SL900A
EPC Class 3 Sensory Tag Chip - For
Automatic Data Logging
General Description
The SL900A is an EPC global Class 3 sensory tag chip optimized
for single-cell and dual-cell, battery-assisted smart labels with
sensor functionality. The chip is ideal for applications using thin
and flexible batteries but can also be powered from the RF field
(electromagnetic waves from an RFID reader).
The chip has a fully integrated temperature sensor with a typical
nonlinearity of ±0.5ºC over the specified temperature range.
The external sensor interface provides a flexible way of adding
additional sensors to the system and supports up to 2 external
sensors.
Ordering Information and Content Guide appear at end of
datasheet.
Key Benefits & Features
The benefits and features of SL900A, EPC Class 3 Sensory Tag
Chip - For Automatic Data Logging are listed below:
Figure 1:
Added Value of using SL900A
Benefits
Features
Versatile temperature and data logging
High Temperature Range: -40°C to +125°C
Worldwide EPC compliant
Frequency: 860 to 960 MHz
Works fully passive or in BAP mode
Battery supply: 1.5V or 3V
Programmable logging modes with various sensors
Data logging from:
• On-chip temperature sensor
• 2 external sensors
Works with EPC readers
EPC Class 1 and Class 3 Compliant
Provides supply for external sensors
Energy harvesting from reader field
Autonomous data logging with timestamp
Real-time clock for data logging
Sensor alert function
External sensor interrupt capability
Supports fast communication via SPI
Serial peripheral interface
Storage for up to 841 events with timestamps
On-chip 9k bit EEPROM
Alert for shelf life expiration
Integrated dynamic shelf life calculation
Programmable sensor limits
Advanced logging with 4 user-selectable limits
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 1
Package Options
The available SL900A package options are:
• 16-pin QFN (5 x 5 mm)
• Tested wafer (8”)
Applications
The SL900A device is ideal suited for:
• Monitoring and tracking of temperature-sensitive
products
• Temperature monitoring of medical products
• Pharmaceutical logistics
• Monitoring of fragile goods transportation
• Dynamic Shelf Life applications
• RFID to SPI interface
Block Diagram
The functional blocks of this device for reference are
shown below:
Figure 2:
SL900A Block Diagram
VBAT
1.5V
or 3V
VSS
Power
Management
EXT1
Temperature
Sensor
VDD
VPOS
Battery Voltage
External
Sensor
Front-End
VSSA
ANT
SCLK
SPI
Port
(Slave)
Processing
Digital Control
EPC Gen2
Class 3
(cool-Log™)
FIFO
SEN
MEAS
ANA TEST
DIGI TEST
EXC
VREF
860 - 960 MHz
AFE
DIN
DOUT
EXT2
1152 x 8 Bit
EEPROM
MUX
10-Bit A/D
Converter
Oscillator
with RTC
SL900A
SL900A Block Diagram: Basic block diagram of SL900A
SL900A – 2
ams Datasheet: 2014-May-06 [v1-01]
Pi n A s s i g n m e n t
The SL900A pin assignments are described below.
Pin Assignment
ANA_TEST
EXC
MEAS
VBAT
Figure 3:
Pin Layout
16
15
14
13
VPOS
1
12
DOUT
VSSA
2
11
DIN
10
SCLK
9
SEN
DIGI_TEST
4
VREF
5
6
7
8
VSS
3
EXT2
ANT
EXT1
SL900A
Figure 4:
Pin Description
Pin Number
Pin Name
1
VPOS
RF rectifier output
2
VSSA
Chip substrate ground – connect to antenna ground
3
ANT
Antenna coil
4
DIGI_TEST
5
VREF
Reference voltage output (Vo2)
6
EXT1
Analog input for external sensor
7
EXT2
Analog input for external sensor
8
VSS
Chip substrate ground – connect to negative battery
terminal. Recommended to connect to VSSA!
9
SEN
Enable input for the SPI interface
10
SCLK
SPI clock
11
DIN
12
DOUT
ams Datasheet: 2014-May-06 [v1-01]
Description
Test input – must be left open
SPI data input
SPI data output
SL900A – 3
Bare Die Pad Layout
Pin Number
Pin Name
Description
13
VBAT
Positive supply input
14
MEAS
Test pin for use during test – must be left open
15
EXC
16
ANA-TEST
Supply voltage for the external sensors or a AC signal source
for external sensors
Analog test pin – must be left open
Pin Description: This table shows a detailed pin description of the SL900A.
Bare Die Pad Layout
Figure 5:
Pad Location Diagram
SL900A – 4
ams Datasheet: 2014-May-06 [v1-01]
B a r e D i e Pa d L a y o u t
Figure 6:
Pad Parameters
Pad name
X position (μm)
Y position (μm)
Pad window (μm)
Type
VREF
77.5
2040.5
85 x 85
Analog Output
EXT1
77.5
1787.5
85 x 85
EXT2
77.5
1098.5
85 x 85
VSS
77.5
223.5
85 x 85
SEN
1822.5
77.5
85 x 85
SCLK
2005.5
77.5
85 x 85
SDATAI
2271.5
77.5
85 x 85
SDATAO
2454.5
77.5
85 x 85
Digital Output
E_SDATAO
2653.5
82.5
85 x 85
Test Pad
VBAT
2657.5
275.5
85 x 85
Supply
MEAS
2648.3
509.15
85 x 85
Test Pad
EXC
2657.5
2144.5
85 x 85
Analog Output
ANA_TEST
2657.5
2327.5
85 x 85
Test Pad
VPOS
2657.5
2510.5
85 x 85
Analog Output
VSSA
2292
2689.5
85 x 85
Supply
ANT2
1396
2696
See RF pad drawing
ANT1
1177
2694
See RF pad drawing
DIGI_TEST
955
2707.5
85 x 85
Analog Input/Output
Supply
Digital Input
Radio-frequency Pad,
Test Pad
Pad locations: Pad locations are measured from lower left chip edge to pad centre.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 5
Absolute Maximum Ratings
Stresses beyond those listed under “Absolute Maximum
Ratings” may cause permanent damage to the device. These are
stress ratings only. Functional operation of the device at these
or any other conditions beyond those indicated under
“Operating Conditions” is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
Absolute Maximum Ratings
Figure 7:
Absolute Maximum Ratings (Operating free-air temperature range, unless otherwise noted)
Parameter
Min
Max
Units
Comments
-0.3
3.7
V
All voltage values are with respect to
substrate ground terminal VSS
100
mA
2
kV
ESD Rating, HBM (RF input pin ANT)
500
V
Maximum Operating Virtual Junction
Temperature, TJ
+150
°C
+150
°C
+260
°C
Input Voltage Range
Maximum Current VPOS, ANT
ESD Rating, HBM (all pins except ANT)
Storage Temperature Range, Tstg
-65
Lead Temperature (soldering, 10 sec.)
Absolute Maximum Ratings: This figure shows the absolute maximum ratings of the SL900A.
Electrical Discharge Sensitivity
This integrated circuit can be damaged by ESD. We recommend
that all integrated circuits are handled with appropriate
precautions. Failure to observe proper handling and installation
procedures can cause damage. ESD damage can range from
subtle performance degradation to complete device failure.
Precision integrated circuits may be more susceptible to
damage because very small parametric changes could cause
the device not to meet the published specifications. RF
integrated circuits are also more susceptible to damage due to
use of smaller protection devices on the RF pins, which are
needed for low capacitive load on these pins.
Operating Conditions
Figure 8:
Operating Conditions
Symbol
VBAT
TA
SL900A – 6
Parameter
Min
Typ
Max
Units
Input Supply Voltage
1.2
1.5
3.6
V
Operating ambient temperature range
-40
+125
°C
ams Datasheet: 2014-May-06 [v1-01]
Electrical Characteristics
Electrical Characteristics
All limits are guaranteed. The parameters with min and max
values are guaranteed with production tests or SQC (Statistical
Quality Control) methods.
TA = -40°C to +125°C, VBAT = 1.5V, unless otherwise noted.
Typical values are at TA = 25°C (1).
Figure 9:
Electrical Characteristics
Symbol
Parameter
Conditions
Min
Typ
Max
Units
3.6
V
Operating Input Voltage
TA = 25°C
VBAT(SU)
Minimum Start-Up Input Voltage
TA = 25°C
1.3
IBAT-OP15
Operating Current into VBAT
Temperature
conversion,
VBAT=1.5V
200
250
μA
IBAT-OP30
Operating Current into VBAT
Temperature
conversion, VBAT=3V
290
350
μA
IBAT-Q
Quiescent Current into VBAT
VBAT = 1.5V; timer
running
1.6
μA
IBAT-SD
Shutdown Current into VBAT
VBAT = 1.5V
0.5
μA
Maximum Current from VPOS pin
In electromagnetic
field
200
μA
VPOS limiter point
In electromagnetic
field
3.4
V
ANTI-QFN
Antenna pad impedance
Measured at
900MHz, QFN
package for PCB
assembly
31-j3
20
Ω
ANTI-DIE
Antenna pad impedance
Measured at
900MHz, bare die for
inlay assembly
9-j33
0
Ω
ANTS
Antenna pad sensitivity
Measured at
900MHz, battery
assisted mode
-15
dBm
VBAT = 1.5V
0.4
V
VBAT = 3V
1
V
VBAT = 1.5V
1
V
2.1
V
VBAT
IEXT
VPOS-l
VIL
VIH
Voltage Input Threshold, Low
(SEN, SCLK, DIN)
Voltage Input Threshold, High
(SEN, SCLK, DIN)
ams Datasheet: 2014-May-06 [v1-01]
VBAT = 3V
1.2
V
SL900A – 7
Electrical Characteristics
Symbol
VOL
VOH
fSCLK
fc
TS-R
TS-R EXT
Parameter
Voltage Output Threshold, Low
DOUT pin
Voltage Output Threshold, High
DOUT pin
Conditions
Min
Typ
Units
VBAT = 1.5V, IDOUT =
1mA
VSS
450m
V
VBAT = 3V, IDOUT =
1mA
VSS
300m
V
1
VBAT
V
2.7
VBAT
V
VBAT = 1.5V
1
MHz
VBAT = 3V
5
MHz
VBAT = 1.5V, IDOUT =
-1mA
VBAT = 3V, IDOUT =
-1mA
SCLK serial data clock
Carrier Frequency
860
960
MHz
Temperature Sensor Range
-20
60
ºC
Extended temperature sensor
range with reduced accuracy
-40
+125
ºC
TS-NL
Temperature sensor nonlinearity
Inside TS-R
±0.5
TS-A
Temperature Sensor Accuracy
Inside TS-R
±1
tsens
Measurement interval
Programmable
tRTC-I
Real-Time Clock, Interval
tRTC-A
Real-Time Clock, Accuracy
Over specified TS-R
temperature range
tRTC-CA
Real-Time Clock, Calibration
Accuracy
TA = 35°C
SL900A – 8
Max
1
ºC
32,768
1
Sec
Sec
-3
+3
%
-0.2
+0.2
%
ams Datasheet: 2014-May-06 [v1-01]
Short Description
Symbol
Parameter
Conditions
Min
Typ
Max
Units
tRTC-B
Real-time Clock, Accuracy
VBAT=1.3V ~ 3V
tRTC-C
Real time clock, Accuracy
VBAT= 1.2V~1.3V;
3V~3.6V
EWCYC
EEPROM Erase/Write Cycles
TA = 25°C
100,000
Cycles
tDR
EEPROM Data Retention Time
TA = 125°C
20
Years
tE/W
EEPROM Erase/Write Speed
rEXC
EXC pin output resistance
rEXT
External sensor interface pads
resistance (EXT1, EXT2, VREF)
±3
-7
+5
7
EXC internally
connected to VBAT
for ext. sensor
supply
%
%
7.5
ms
400
Ω
200
Ω
Note(s) and/or Footnote(s):
1. Limits are 100% production tested at TA = 35°C. Limits over the operating temperature range are guaranteed by design.
Short Description
The SL900A is designed for use in smart active labels (SAL),
semi-passive labels and passive labels. Smart active labels are
defined as thin and flexible labels that contain an integrated
circuit and a power source. SAL includes in its definition both
“fully active” smart labels, and semi-active smart labels, also
known as battery-assisted back-scattered passive labels, both
of which enable enhanced functionality and performance over
passive labels. The IC includes sensor functionality and logging
of sensor data (see Figure 10 below).
The SL900A is operating at 860 to 960 MHz and is fully EPC
global Class 1 compliant. The chip is supplied from a single-cell
battery of typically 1.5V, or from a dual cell battery (3V). The
on-chip temperature sensor and real-time clock (RTC)
accommodate temperature data logging.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 9
Short Description
Supply Arrangement
The SL900A is supplied from either the battery or through the
electromagnetic waves from a reader. The device is normally
supplied from the battery unless there is no battery attached
(passive label), or when the battery is drained.
Figure 10:
Block Diagram
VBAT
1.5V
or 3V
VSS
Power
Management
EXT1
Temperature
Sensor
VDD
VPOS
Battery Voltage
External
Sensor
Front-End
VSSA
ANT
SCLK
860 - 960 MHz
AFE
SPI
Port
(Slave)
Processing
Digital Control
EPC Gen2
Class 3
(cool-Log™)
FIFO
SEN
MEAS
ANA TEST
EXC
VREF
DIN
DOUT
EXT2
1152 x 8 Bit
EEPROM
MUX
10-Bit A/D
Converter
Oscillator
with RTC
SL900A
DIGI TEST
Analog Front End (AFE)
The analog front end is designed according to EPC Gen 2. The
forward link (reader to tag) is amplitude modulated and the
backward link (tag to reader) is amplitude modulated (load
modulation is used).
Processing and Digital Control
The SL900A is fully EPC Class 1 compliant, with additional
custom commands for extended functions. The maximum
transponder to interrogator data rate according to Class
1/Gen.2 is 640 kbit/s. The maximum interrogator to
transponder data rate is 160 kbit/s.
Figure 11:
Supported Data Rates
Data Rate
Min
Max
Interrogator to transponder
40 kbit/s
160 kbit/s
Transponder to interrogator
5 kbit/s
640 kbit/s
SL900A – 10
ams Datasheet: 2014-May-06 [v1-01]
Short Description
Serial Interface (SPI)
The integrated serial interface (SPI) can be used to initialize the
chip and to set the parameters. The logging procedure can be
started and stopped with the SPI. The SPI bus can also be used
for the communication between a microcontroller that is
attached to the SL900A and the RFID reader.
Real-Time Clock (RTC)
The on-chip real-time clock (RTC) is started through the START
LOG command in which the start time is programmed in UTC
format. The interval for sensing and data logging can be
programmed in the range from 1 second up to 9 hours. The
accuracy of the timer is ±3%. The timer oscillator is calibrated
at 35 ºC within ±0.2%.
Temperature Sensor
The on-chip temperature sensor can measure the temperature
in the range from -20ºC to 60ºC with a typical accuracy of ±1ºC.
The full temperature range of -40ºC to +125ºC has a reduced
accuracy.
External Sensors
The on-chip external sensor front end provides a flexible
interface for analog external sensors. It has an auto-range and
interrupt function. It supports various types of analog sensors
from pressure, humidity, temperature, light …
Analog to Digital Converter
The chip has an integrated 10-bit analog to digital converter
with selectable voltage references. It is used for conversion of
temperature, external sensors and battery voltage.
External Sensor Interrupt
The external sensor inputs EXT1 and EXT2 can be used for
event-triggered logging. In this mode, the logging is not
triggered in predefined time intervals from the internal timer,
but can be triggered externally, either with a sensor, switch or
a microcontroller.
The interrupt source can be the EXT1, EXT2 input or both, were
the EXT1 input has the higher priority. The user application can
select which measurements are triggered by the interrupt
event.
In the interrupt mode, the sensor value is stored together with
the 32-bit real time clock value. For a correct real-time clock
value, the correct Start time has to be supplied. The interrupt
mode is started with the START LOG command and the correct
setting in the registers (SET LOG MODE command).
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 11
Short Description
Data Protection
Additional to the Gen2 lock protection, the SL900A offers
read/write protection using 3 password sets for 3 memory
areas. Each 32-bit password is divided into 2 16-bit passwords,
where the lower 16 bits are reserved for the Write protection
and the higher 16 bits are reserved for the Read/Write
protection.
Shelf Life
The SL900A device has an integrated shelf life algorithm that
can dynamically calculate the remaining shelf life of the
product. It has an automatic alarm function for the shelf life
expiration. This can be used to directly drive a LED or as an
interrupt for an external microcontroller.
Memory arrangement
The SL900A device has an integrated 9kbit EEPROM. It is
organized into 5 memory banks shown below.
Figure 12:
Memory Arrangement
Memory Bank
Bank Size (bits)
SYSTEM
512
System parameters like calibration data and log
parameters
RESERVED
64
Access and Kill password
EPC
144
PC and EPC value
TID
80
Unique identifier – programmed and locked during
production
USER
8416
SL900A – 12
Comments
User and measurement data
ams Datasheet: 2014-May-06 [v1-01]
System Description
System Description
Figure 14 shows the different states and their interactions.
Figure 22 shows the command overview.
Initializing the Chip
A virgin chip (not initialized) can be initialized either through
the SPI port or through the electromagnetic field from a reader
in the standby mode. The power source is either from a battery
(VBAT ) or extracted from the RF field via the AFE circuit. After
the initializing procedure, the chip will enter the ready mode.
Power Modes
Ready Mode
In the ready mode, all parameters can be set, read and changed
through a reader with the appropriate passwords.
Active Mode
In active mode, the real-time clock (RTC) is running, the desired
parameters are set, and the on-chip temperature sensor is in
standby.
Logging Mode
A log flag from the timer will enable the logging mode in which
the sensor and the A/D converter will be activated, and the
measured value will be stored in the EEPROM together with the
time of the event. If the external sensor flag is set, the external
sensors will also be activated and the measured data stored.
The A/D converter can be multiplexed between internal
temperature sensor, external sensors or battery voltage. After
the event, the chip will return to the active mode.
Interrupt Mode
In the interrupt mode, the external sensor interrupt block is
running with minimal power consumption. When the external
sensor value exceeds a specified threshold, the chip goes into
the logging mode where the selected sensor values and real
time of the event are stored to the EEPROM.
Stand-by Mode
In passive mode, all blocks in the chip are turned off and only
the leakage current is flowing. When the label enters an RF field,
it will go from Stand-by mode to Ready mode. If the SEN pin
rises high, the chip will go from the Stand by mode to the serial
mode
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 13
System Description
Figure 13:
Modes of Operation
Mode
IBAT (Typ.)
Power from AFE
In passive mode the chip is turned off and only the
leakage current is flowing
0.1 μA
No
Serial
Enables initializing and executing of all commands via
the SPI bus
50 μA
No
Ready
Chip is initialized and all commands can be executed
via the reader
50 μA
Yes
2 μA
No
Stand-by
Description
Active
• RTC running
• Sensor standby
Interrupt
• RTC running
• External sensor minimum supply
2.5 μA
No
Logging
• Sensor reading (on-chip temperature sensor,
battery voltage level and/or external sensor
through the MMI pin)
• Measured data stored in EEPROM
• RTC time stored in EEPROM
180 μA
No
State Diagram
Figure 14:
State Transition Diagram
SPI REQUEST:
ALL
SEN=0
SPI Stop
logging
Serial
SPI Start
Logging
SEN=1
Stand-by
LOG-TIMER or
IRQ
SEN=1
SEN=0
Active or
Interrupt
Logging
START-LOG
RF on
LOG-FINISHED
Ready
END-LOG
RF off
READER REQUEST:
ALL COMMANDS
SL900A – 14
READER REQUEST:
ALL EPC standard
COMMANDS
SET PASSWORD
GET MEASUREMENT SETUP
SET PASSIVE
GET LOG STATE
GET CALIBRATION DATA
GET BATTERY LEVEL
OPEN AREA
GET SENSOR VALUE
Temperature
measurement.
Battery
measurement.
Limits comparison.
Shelf life.
External sensor
measurement.
Log to EEPROM.
ams Datasheet: 2014-May-06 [v1-01]
System Description
Data Protection
Additional to the Gen2 lock protection, the SL900A offers
read/write protection using 3 password sets for 3 memory
areas. The System area is protected by the System password,
the Application area is protected by the Application password,
and the Measurement area is protected by the Measurement
password. Each 32-bit password is divided into 2 16-bit
passwords, where the lower 16 bits are reserved for the Write
protection and the higher 16 bits are reserved for the
Read/Write protection.
The password can be set either with the custom RFID command
SET PASSWORD, or through the SPI, by writing the password to
the password locations.
The password protection is activated immediately after the SET
PASSWORD command. In case the passwords are written with
the SPI interface, the protection is activated when the
transponder re-enters an RF field.
Password protection does not block any read/write operation
on the SPI interface; it is active only for the RFID interface.
Figure 15:
Password Storage in System Memory
Address
Data
0x000
System Password [31:24]
0x001
System Password [23:16]
0x002
System Password [15:8]
0x003
System Password [7:0]
0x004
Application Password [31:24]
0x005
Application Password [23:16]
0x006
Application Password [15:8]
0x007
Application Password [7:0]
0x008
Measurement Password [31:24]
0x009
Measurement Password [23:16]
0x00A
Measurement Password [15:8]
0x00B
Measurement Password [7:0]
Function
System Password – read/write protect
System Password - write protect
Application Password – read/write protect
Application Password - write protect
Measurement Password – read/write protect
Measurement Password - write protest
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 15
System Description
Data Log Functions
The SL900A device supports various flexible data log formats.
The data log format depends on the Logging form. The data log
formats are defined in Figure 23.
The Logging form is set with the SET LOG MODE command and
is stored in “Logging form [2:0]” (SPI address 0x026) bits in the
EEPROM.
Figure 16:
Supported Logging Formats
Bit 2
Bit 1
Bit 0
0
0
0
Dense
All values are stored to the measurement area. No
additional time information is stored to the measurement
area.
1
All values out of
limits
All values that are out of the specified limits are stored to
the measurement area. Additional to the sensor value,
also the measurement number is stored, so the
application can reconstruct the time-sensor points.
Limits crossing
Only the crossing point of each limit boundary is stored.
Additional to the sensor value, also the measurement
number is stored, so the application can reconstruct the
time-sensor points.
IRQ, EXT1
Interrupt triggered on the EXT1 external sensor input. At
each trigger event the selected sensor values are stored.
Additional to the sensor values, also the real-time clock
offset is stored.
IRQ, EXT2
Interrupt triggered on the EXT2 external sensor input. At
each trigger event the selected sensor values are stored.
Additional to the sensor values, also the real-time clock
offset is stored.
IRQ, EXT1, EXT2
Interrupt triggered on the EXT1 and EXT2 external sensor
input. At each trigger event the selected sensor values are
stored. Additional to the sensor values, also the real-time
clock offset is stored.
0
0
1
1
1
0
1
0
1
1
1
1
0
1
Logging From
Description
When the “IRQ + timer enable” bit (Initialize command, SPI
address 0x02A) is set to 1, the logging will be triggered on the
selected time interval (timer) and also on an interrupt from
external sensor1, sensor 2 or both – depending on the selected
logging mode.
The Storage rule bit defines what happens when the logging
area in the EEPROM is full.
SL900A – 16
ams Datasheet: 2014-May-06 [v1-01]
System Description
Figure 17:
Storage Rule
Bit
Storage Rule
Description
0
Normal
When the logging area in the EEPROM is full, the chip does not store any new
sensor data to the EEPROM, but it will still increment the measurement counter
and RTC.
Rolling
When the logging area is full, the chip continues with writing new sensor data
to the EEPROM form the beginning of the logging area. Thus the chip
overwrites the old stored data and increments the “Number of memory
replacements [5:0]” field in the System status group.
1
Limits Counter
The Limits counter can be used as an advanced alarm
mechanism. It is enabled in all log formats and it will display
the cumulative number of measurements that are outside
limits. The application does not have to read the whole EEPROM
content in order to determine if the temperature limits have
been exceeded, just the Limits counter block. The Limits
counter block can be read out with the GET LOG STATE
command.
The system uses 4 limits that can be set by the user:
• Extreme upper limit
• Upper limit
• Lower limit
• Extreme lower limit
There is a dedicated 8-bit counter for each of the 4 limits in the
Limits counter block. The appropriate counter will increment
each time a sensor value is outside a limit.
The user can select which sensor will be used in the limits
comparison. The internal temperature sensor is selected by
default. Other sensors can be selected with the SET SFE
PARAMETERS command with the “Verify sensor ID[1:0]” field
(SPI address 0x018):
Figure 18:
Modes of Operation
Verify Sensor ID Bit 1
Verify Sensor ID Bit 0
0
0
Internal temperature sensor - DEFAULT
0
1
External sensor 1
1
0
External sensor 2
1
1
Battery voltage
ams Datasheet: 2014-May-06 [v1-01]
Sensor Selected for Limits Comparison
SL900A – 17
System Description
Logging Timer
The SL900A device has an integrated RC oscillator that is
calibrated to 1024Hz. This oscillator drives the logging timer.
The logging timer resolution is 1 second. The maximum period
is 9.1 hours (32768 seconds). The logging interval is
programmed with the SET LOG MODE command.
The measurement real time is derived from 4 parameters - the
Start time (ST), the Delay time (DT), the log interval (LT), and
the # of the measurement (NM). This value has to be calculated
in the reader by the equation:
Real time = ST+DT+LT*NM
Delay Time
The SL900A supports delayed start of the logging procedure.
The Delay time has a resolution of 8 minutes - 32 seconds (512
seconds) and a maximum value of 582 hours (12 bits). The delay
time value is set with the Initialize command, while the Delay
time counter starts counting when the device receives the
START LOG command.
The delay time can also be disabled and an external push button
can be used for starting the logging procedure.
Analog to Digital Conversion
The chip has an integrated analog to digital converter with
10-bit resolution and selectable voltage references. By default,
the references are selected as: Vo1 = 0V and Vo2 = 310mV. This
results in a voltage input range of 310mV ~ 620mV, for the
temperature conversion this is -89.3ºC ~ +94.6ºC.
The voltage references are individually selectable in 50mV steps
with a fine adjustment for offset calibration. Additionally, the
Vo1 reference voltage can be tied directly to ground if the bit
“gnd_switch” in the SET CALIBRATION DATA command is set to
1 (SPI address 0x012).
SL900A – 18
ams Datasheet: 2014-May-06 [v1-01]
System Description
Figure 19:
AD Reference Voltages
Calib. Code
Vo1
Vo2
0b000
160mV
260mV
0b001
210mV
310mV
0b010
260mV
360mV
0b011
310mV
410mV
0b100
360mV
460mV
0b101
410mV
510mV
0b110
460mV
560mV
0b111
510mV
610mV
The Vo2 voltage defines the lower temperature limit for the
temperature conversion – note that normal operation is not
guaranteed below -40 ºC.
Figure 20:
Theoretical Lower Temperature Limit
Vo2
Low. Temp. Lim.
260mV
-118.9 ºC
310mV
-89.3 ºC
360mV
-59.6 ºC
410mV
-29.0 ºC
460mV
0.3 ºC
510mV
29.3 ºC
560mV
59.0 ºC
610mV
88.7 ºC
The voltage difference between the Vo2 and Vo1 references
define the resolution and temperature range.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 19
System Description
Figure 21:
Temperature Conversion Resolution and Range
Vo2 - Vo1
Resolution
Range
310mV (default)
0.18 ºC
183.9 ºC
50mV
0.029 ºC
29.7 ºC
100mV
0.058 ºC
59.3 ºC
150mV
0.086 ºC
88.0 ºC
200mV
0.116 ºC
118.6 ºC
250mV
0.145 ºC
148.3 ºC
260mV
0.151 ºC
154.2 ºC
300mV
0.174 ºC
177.9 ºC
350mV
0.203 ºC
207.6 ºC
360mV
0.209 ºC
213.5 ºC
400mV
0.232 ºC
237.2 ºC
Example:
Vo1 = 310mV, Vo2 = 410mV -> A/D conversion temperature
range = -29.3ºC ~ 30.0 ºC.
Temperature resolution = 0.058 ºC.
The converted voltage can be calculated from the following
equation:
Vo2 – Vo1
V SENS = code ⋅ ---------------------------- + Vo2
1024
SL900A – 20
ams Datasheet: 2014-May-06 [v1-01]
System Description
Temperature Conversion
The calibration data does not have to be included in the
temperature conversion equation. The temperature value
calculation is dependent on the selected voltage references
(See “Analog to Digital Conversion” on page 18.):
T ⋅ ( °C ) = code∗ Resolution – Low ⋅ temp ⋅ limit
By default (factory setting), the voltage references are set: Vo1
= 0V, Vo2 = 310mV. This yields a theoretical temperature
conversion range of -89.3ºC ~ +94.6ºC. The temperature
conversion equation for this setting is:
T ⋅ ( °C ) = code∗ 0.18°C – 89.3°C
LSB = 0.18°C
Offset = ( – 89.3 )°C
When the reference voltages are set to some other value, the
following equation needs to be used for temperature
conversion:
Vo2 [ mV ] ⋅ ( code + 1024 ) – code ⋅ Vo1 [ mV ]
T ⋅ ( °C ) = ------------------------------------------------------------------------------------------------------------------ – 273.15
1024 ⋅ 1.686
The Vo1 and Vo2 in the above equation have to be in mV.
Battery Voltage Conversion
The battery voltage conversion is dependent on the initial
battery voltage (1.5V or 3V) and on the selected voltage
references (See “Analog to Digital Conversion” on page 18.). The
conversion equations with factory selected voltage references
(Vo1 = 0V, Vo2 = 310mV) are:
For 1.5V battery, the equation is:
• V = code*0.85mV + 873mV
• LSB = 0.85mV
• Offset = 873mV
For 3V battery:
• V = code*1.65mV + 1.69V
• LSB = 1.65mV
• Offset = 1.69V
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 21
Commands
Some commands can be password protected by 3 different
passwords: System password (S), Application password (A) or
Measurement password (M).
Commands
Figure 22:
EPC Gen2 and Cool-Log™ Command Overview
SERIAL
READY
01
QueryRep
0b00
-
√
√
02
ACK
0b01
-
√
√
03
Query
0b1000
-
√
04
QuaryAdjust
0b1001
-
05
Select
0b1010
06
NAK
07
Req_RN
09
Read
Write
10
SL900A – 22
Kill
STAND-BY
Command
08
ACTIVE
#
LOGGING
Allowed in Modes
Command
Code
Mode
Change
Security
Level
√
-
No
/
EPC Gen2
anticollision round
command
√
-
Yes
/
EPC Gen2
anticollision round
command
√
√
-
No
/
EPC Gen2
anticollision round
command
√
√
√
-
No
/
EPC Gen2
anticollision round
command
-
√
√
√
-
No
/
EPC Gen2
anticollision round
command
0xC0
-
√
√
√
-
No
/
EPC Gen2
anticollision round
command
0xC1
-
√
√
√
-
No
/
Request for a new
16-bit random
number
A or M
Reads the selected
block in the
specified memory
bank
A or M
Writes the selected
block in the
specified memory
bank
/
Kills the transponder
– no RFID access is
possible after this
command (SPI
remains active)
0xC2
0xC3
0xC4
-
-
-
√
√
√
√
√
√
√
√
√
-
-
-
No
No
No
Definition
ams Datasheet: 2014-May-06 [v1-01]
Commands
Command
Code
SERIAL
READY
11
Lock
0xC5
-
√
√
12
Access
0xC6
-
√
√
√
14
BlockWrite
BlockErase
0xC7
0xC8
-
-
√
√
√
√
STAND-BY
Command
13
ACTIVE
#
LOGGING
Allowed in Modes
Mode
Change
Security
Level
√
-
No
/
Locks the selected
memory banks
-
No
/
Puts the transponder
to the secured state
A or M
Writes the selected
block in the
specified memory
bank
A or M
Erases the selected
block in the
specified memory
bank
√
√
-
-
No
No
Definition
Note: The cool-Log commands are defined as EPC custom commands. All custom commands have a 16-bit
command code, where the 1st command code is defined as 0xE0, the second command code is in the
table below.
15
Set Password
0xA0
-
√
√
√
-
No
S, M or A
Sets the passwords
to EEPROM
16
Set Log Mode
0xA1
-
√
√
-
-
No
S
Sets logging mode
17
Set Log
Limits
S
Sets the
measurement limits
for limits logging
mode
0xA2
-
√
√
-
-
No
18
Get
measurement
setup
0xA3
-
√
√
√
-
No
S
Reads 4 system
blocks - Start time,
Log limits, Log
mode, and Delay
time + application
area size
19
Set SFE
parameters
0xA4
-
√
√
-
-
No
S
Sets parameter for
the External sensor
front end
20
Set
Calibration
Data
S
Sets the calibration
data for the
temperature sensor
and timer
S
Stops the log
procedure and
returns the chip to
Standby mode
21
End Log
0xA5
0xA6
ams Datasheet: 2014-May-06 [v1-01]
-
-
√
√
√
-
-
√
-
-
No
Yes
SL900A – 23
Commands
Command
Code
SERIAL
READY
22
Start Log
0xA7
-
√
√
23
Get Log State
0xA8
-
√
√
24
Get
calibration
data
0xA9
-
√
25
Get Battery
level
0xAA
-
26
Set Shelf Life
0xAB
-
Initialize
0xAC
-
STAND-BY
Command
27
ACTIVE
#
LOGGING
Allowed in Modes
Mode
Change
Security
Level
Definition
-
-
Yes
S
Starts the timer and
the selected log
procedure
√
-
No
S
Gets the log state of
the chip
√
√
-
No
S
Reads the internal
and external
calibration data
√
√
√
-
No
/
Measures the
battery voltage
√
√
-
-
No
/
Set the shelf life
parameters
S
Initializes the chip
and sets the
aapplication area
size and the logging
delay
√
√
-
-
No
28
Get Sensor
Value
0xAD
-
√
√
√
-
No
/
Measures the
specified sensor –
temperature, ext.
sensor1 or ext.
sensor 2
29
Open Area
0xAE
-
√
√
√
-
No
/
Opens access to the
specified EEPROM
area
/
Reads or writes the
8-byte FIFO register
(for fast SPI to RFID
data transfer)
30
Access FIFO
SL900A – 24
0xAF
-
√
√
√
-
No
ams Datasheet: 2014-May-06 [v1-01]
Commands
Supported EPC Gen2 Commands
QuerryREP - #01
The QUERRY_REP command instructs tags to decrement their
slot counter and is specified for one out of 4 sessions. If the slot
counter becomes 0 after decrementing, the tag will backscatter
its RN16.
ACK - #02
When a tag receives the ACK command in the Reply state, it will
transition to the Acknowledged state and backscatter the EPC.
The EPC can be truncated if this has been requested by the
reader in the SELECT command. The ACK command can also be
processed in the Open or Secured states, but in this case no
state transition will occur.
Query - #03
The QUERY command initiates and specifies an inventory
round. It sets the TX and RX data rates. It also defines the
number of slots used for the inventory round. When the tag
receives the QUERY command, it will calculate a random RN16
if it has a matching Sel and Target. The tag will backscatter the
RN16 value in case the slot counter is loaded with 0.
QueryAdjust - #04
The QUERY_ADJUST command increments or decrements the
Q number (number of slots) for the current inventory round.
Select - #05
The SELECT command selects a tag population that will
participate in the inventory round, based on user-defined
criteria. The tag can receive any number of successive SELECT
commands.
NAK - #06
When a tag receives the NAK command, it will transition to the
Arbitrate state, unless it is in the Kill or Ready states. The tag
will not send any reply to the NAK command.
Req_RN - #07
The REQ_RN command will instruct the tag to backscatter a new
RN16. When a tag in the Acknowledged state receives a correct
REQ_RN command, it will transition to the Open or Secured
state. When the tag is in the Open or Secured state, it will
backscatter a new RN16 and no state transition will occur.
Read - #08
The Read command instructs the tag to read and backscatter a
part or all of the Reserved, EPC, TID or User memory.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 25
Commands
Write - #09
The WRITE command allows the interrogator to write a word (16
bits) in the tags Reserved, EPC, TID or User memory. Prior to
sending the Write command, the interrogator has to send the
REQ_RN command in order to receive a new RN16 that will be
used for cover-coding the data by EXOR-ing it with the RN16.
In case the data writing has been successful, the tag will
backscatter the response within 20ms after receiving the
command.
Kill - #10
The KILL command is used to permanently disable a tag. When
the tag receives the correct multi-step Kill procedure, it will
transition to the Killed state and will not send any response
thereafter.
Lock - #11
The LOCK command instructs the tag to lock the specified block
of the EEPROM memory. The Kill and Access passwords can be
Read/Write locked, while the EPC, TID and User block can only
be Write locked. The command will only be executed in the
Secured state.
Access - #12
The ACCESS command with a correct password and correct
multi-step procedure instructs the tag to transition from the
Open to the Secured state. When the tag has successfully
received the multi-step access procedure, it will backscatter its
handle.
BlockWrite - #13
The BLOCK_WRITE command writes a single word of data (16
bits) to the specified memory address. It provides faster data
writing than the WRITE command as it does not need a new
RN16 for every word of data that has to be written. In case the
data writing has been successful, the tag will backscatter the
response within 20ms after receiving the command.
BlockErase - #14
The BLOCK_ERASE command erases a single word in the
specified memory bank. In case the erase has been successful,
the tag will backscatter the response within 20ms after
receiving the command.
SL900A – 26
ams Datasheet: 2014-May-06 [v1-01]
Commands
Cool-Log Custom Commands
Set Password - #15
The SET PASSWORD command sets the password for the
specified memory area. This is the System area, Application area
and Measurement area. The System area is in the Reserved
memory bank. The Application and Measurement areas are in
the User memory bank. In case the command has executed
successfully, the tag will backscatter the response within 20ms
after receiving the command.
Set Log Mode - #16
The SET LOG MODE command sets various parameters for the
logging procedure. In case the command has executed
successfully, the tag will backscatter the response within 20ms
after receiving the command.
Set Log Limits - #17
The SET LOG LIMITS command write the 4 limits that are going
to be used for logging measurement data. The limits are:
Extreme upper limit, Upper limit, Lower limit and Extreme lower
limit. In case the command has executed successfully, the tag
will backscatter the response within 20ms after receiving the
command.
Get Measurement Setup - #18
The GET MEASUREMENT SETUP command reads 4 system blocks
- Start time, Log limits, Log mode and Delay time.
Set SFE Parameters - #19
The SET SFE PARAMETERS command sets the parameters for the
External sensor front end.
Set Calibration Data - #20
The SET CALIBRATION DATA command sets the calibration
values for the internal temperature sensor.
WARNING – the factory preset calibration data can be
overwritten. It is advised to read the calibration data, change
only the required bits and write back with the SET CALIBRATION
DATA command.
End Log - #21
The END LOG command stops the logging procedure and
returns the chip to passive mode. It also stops the timer.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 27
Commands
Start Log - #22
The START LOG command starts the logging procedure and sets
the Start time in UTC format. In logging state the chips
automatically performs the measurements and data logging in
the specified time intervals. Supported is also a delayed start,
which means that the chip will start with the logging procedure
with a specified delay after it receives the START LOG command.
This command also starts the Interrupt mode of operation
where the measurements and data-logging are driven from
external events.
Get Log State - #23
The GET LOG STATE command gets the log state of following
parameters: measurement status and out of limits counter. This
gives the ability to quickly check the state of the package
without the need to read the whole temperature data log.
Get Calibration Data - #24
The GET CALIBRATION DATA command reads the calibration
data for the internal and external sensors.
Get Battery Level - #25
The GET BATTERY LEVEL command measures and reads the
voltage level of the battery.
Set Shelf Life - #26
The SET SHELF LIFE command writes the shelf life algorithm
parameters and enables the dynamic shelf life calaculation.
Initialize - #27
The INITIALIZE command sets the size of the application data
area and sets the delay time. The command clears the
measurement status and limits counter blocks.
Get Sensor Value - #28
The GET SENSOR VALUE command measures and backscatters
the value of the specified sensor – internal, external 1 or
external 2.
Open Area - #29
The OPEN AREA command opens the specified area of the
memory (System, Application, and Measurement). The
password is stored in a RAM location and compared with the
password in EEPROM. When the tag leaves the RF field, this RAM
location is cleared.
Access FIFO - #30
The ACCESS FIFO command can read or write the 8-byte FIFO.
The FIFO can also be accessed from the SPI so this command
can be used for fast data transfer between a microcontroller
connected to the SPI and an RFID reader.
SL900A – 28
ams Datasheet: 2014-May-06 [v1-01]
Custom Command Description
Custom Command Description
Upon receiving a valid command, the tag always transmits a
reply. If the command can not be executed, the tag replies with
the following error message:
Reply Structure (error):
SOF
Header
Error code
Handle
CRC
EOF
Pilot tone + preamble
1 bit [1]
8 bits
16 bits
16 bits
Dummy bit [1]
The error codes are defined as:
Error Code
Error Name
Error Description
Condition
Other error
For error s that are not covered by
the other specified error codes
00000011
Memory overrun
The specified memory location
does not exist or the EPC length
field is not supported by the tag
The EBV address is outside the
physical address of the EEPROM
or outside the specified memory
bank.
00000100
Memory locked
The specified memory location is
locked and/or permalocked and
can not be read or written.
The lock bit for the specified
memory bank or password is
set.
00001011
Insufficient power
The tag has insufficient power to
perform the memory write
operation.
This error code can only be set in
fully passive mode when the
supply voltage is to low.
10100000
Incorrect password
The password is incorrect – tag is
not open.
The IDS custom password
protection is active.
10100010
Battery
measurement error
The battery measurement can not
be started.
The tag is fully passive and there
is no battery attached.
00000000
10100011
Command not
allowed
Command is not allowed in active
state.
Custom commands that can
modify logging and calibration
parameters are not allowed
when the tag is in active state
(RTC running).
10100110
EEPROM busy error
The memory can not be accessed
as the measurement unit or SPI is
accessing the EEPROM.
This error is reported when the
EEPROM is used by the SPI or
measurement unit.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 29
Custom Command Description
Set Password
The SET PASSWORD command writes a 32 - bit password to the
EEPROM. The password protection for the specified area is
automatically enabled if the password is any other value
except 0.
Command Structure:
SOF
Custom
Command Code
Password Level
Password
Handle
CRC
Frame-sync
0xE0
0xA0
8 bits
32 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
The “Password Level” bits are:
Password Level Bits
b1
b0
Passw. level
0
0
Not allowed
0
1
System
1
0
Application
1
1
Measurement
Bits b7 - b2 are X
When the System area is open for writing, the Set password can
change the passwords for all 3 password levels. When the
System area is write-protected, the Set password command can
not change the System password, but it can change the
Application password, if the Application area is open, and the
Measurement password when the Measurement area is open.
Set Log Mode
The SET LOG MODE command sets the logging form, storage
rule, enables sensors that are used in the logging process and
sets the logging interval (in 1 second steps).
Command Structure:
SOF
Custom
Command Code
Log Mode
Handle
CRC
Frame - sync
0xE0
0xA1
24 bits
16 bits
16 bits
SL900A – 30
ams Datasheet: 2014-May-06 [v1-01]
Custom Command Description
In case the operation is successful, the following reply will be
sent:
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
The “Log mode” field is composed as:
Bit
Number
23 … 21
20
19
18
17
16
15 … 1
0
Function
Logging
form [2:0]
Storage
rule
Ext.1 sensor
enable
Ext.2 sensor
enable
Temp. sensor
enable
Battery check
enable
Log interval
[14:0]
RFU
Set Log Limits
The SET LOG LIMITS command writes the 4 limits that are used
in the logging process. All 4 limits are 10 bits long.
Command Structure:
SOF
Custom
Command Code
Log Limits
Handle
CRC
Frame - sync
0xE0
0xA2
40 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
The “Log Limits” field is composed as:
Bit Number
39 … 30
29 ... 20
19 … 10
9…0
Function
Extreme lower limit
Lower limit
Upper limit
Extreme upper limit
Get Measurement Setup
The GET MEASUREMENT SETUP command will read the current
system setup of the chip.
Command Structure:
SOF
Custom
Command Code
Handle
CRC
Frame - sync
0xE0
0xA3
16 bits
16 bits
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 31
Custom Command Description
Successful Reply Structure:
SOF
Hea
der
Start
Time
Log
Limits
Log
Mode
Log
Interval
Delay
Time
Applic
ation
Data
Han
dle
CRC
EOF
Pilot tone
+
preamble
1 bit
[0]
32
bits
40
bits
8
bits
16
bits
16
bits
16
bits
16
bits
16
bits
Dum
my
bit [1]
The “Log Limits” field is composed as:
Bit Number
39 … 30
29 ... 20
19 … 10
9…0
Function
Extreme lower limit
Lower limit
Upper limit
Extreme upper limit
The “Log Mode” field is composed as:
Bit Number
7 ... 5
4
3
2
Function
Logging form [2:0]
Storage rule
Ext.1 sensor enable
Ext.2 sensor enable
The “Log Interval” field is composed as:
Bit Number
15 … 1
0
Function
Log interval [14:0]
RFU
The “Delay Time” field is composed as:
Bit Number
15 … 4
3…2
1
0
Function
Delay time [11:0]
RFU [1:0]
Delay mode [0 – timer, 1 –
external switch]
IRQ+timer enable
The “Application Data” field is composed as:
Bit Number
15 … 7
6…3
2…0
Function
Number of words for application data [8:0]
RFU [3:0]
Broken word pointer [2:0]
SL900A – 32
ams Datasheet: 2014-May-06 [v1-01]
Custom Command Description
Set SFE Parameters
The SET SFE PARAMETERS command writes the Sensor Front
End parameters to the memory. Those parameters include the
range preset values for the external sensor inputs, external
sensor types and the also the sensor that will be used for limits
comparison.
Command Structure:
SOF
Custom
Command Code
SFE Parameters
Handle
CRC
Frame - sync
0xE0
0xA4
16 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
The “SFE Parameters” field is composed as:
Bit Number
15 … 11
10 … 6
5…4
3
2
1…0
Function
Rang [4:0]
Seti [4:0]
EXT1 [1:0]
EXT2
Autorange
disable
Verify sensor
ID [1:0]
Set Calibration Data
The SET CALIBRATION DATA write to the calibration block in the
EEPROM memory. The calibration data is preset during
manufacturing, but can also be changed in the application if
needed. The SET CALIBRATION DATA will write only to the
EEPROM, but it will not update the calibration values in the
calibration registers. The calibration registers are automatically
updated with each START LOG command.
Command Structure:
SOF
Custom
Command Code
Calibration Data
Handle
CRC
Frame - sync
0xE0
0xA5
56 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
Note: The “Calibration data” field is composed of 7 bytes (See “Calibration Bits” on page 63.).
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 33
Custom Command Description
End Log
The END LOG command stops the logging procedure and turns
off the real time clock. It also clears the Active flag that is store
in the “System status” field in the EEPROM.
Command Structure:
SOF
Custom
Command Code
Handle
CRC
Frame - sync
0xE0
0xA6
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
Start Log
The START LOG command starts the logging process. It
refreshes the data in the calibration registers, enables the RTC,
writes the Start time and sets the Active bit in the “System
status” field in the EEPROM.
Command Structure:
SOF
Custom
Command Code
Start Time
Handle
CRC
Frame - sync
0xE0
0xA7
32 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
The “Start Time” field is composed as:
Bit Number
31 … 26
25 … 22
21 … 17
16 … 12
11 … 6
5…0
Function
Year [5:0]
Month [3:0]
Day [4:0]
Hour [4:0]
Minute [5:0]
Second [5:0]
SL900A – 34
ams Datasheet: 2014-May-06 [v1-01]
Custom Command Description
Get Log State
The GET LOG STATE command reads the status of the logging
process. The command can be used to quickly determine the
current state of the product, together with the Shelf life and the
Limit counter.
Command Structure:
SOF
Custom
Command Code
Handle
CRC
Frame - sync
0xE0
0xA8
16 bits
16 bits
Successful Reply Structure:
SOF
Hea
der
Limit
Counter
System
Status
SL-bloc
k 0&1
Current
Shelf
Life
Status
Flags
Han
dle
CRC
EOF
Pilot tone
+
preamble
1 bit
[0]
32
bits
32
bits
64 bits
(see Note)
24 bits
(see Note)
8
bits
16
bits
16
bits
Dum
my
bit [1]
OPTIONAL - only when Shelf Life flag is set in the EEPROM.
The “Limit Counter” field is composed as:
Bit Number
31 … 24
23 … 16
15 … 8
7…0
Function
Extreme lower [7:0]
Lower [7:0]
Upper [7:0]
Extreme upper [7:0]
The “System Status” field is composed as:
Bit Number
31 … 22
21 … 16
15 … 1
0
Function
Measurement address
pointer [9:0]
Number of memory
replacements [5:0]
Number of
measurements [14:0]
Active
The “Status Flags” field is composed as:
Bit Number
7
6
5
4
3
2
1
0
Function
Active
(logging
process)
Measure
ment
area full
Measurement
overwritten
AD
error
Low
battery
Shelf life
low error
Shelf life
high
error
Shelf
Life
expired
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 35
Custom Command Description
Get Calibration Data
The GET CALIBRATION DATA command reads the calibration
data field and the SFE parameters field.
Command Structure:
SOF
Custom
Command Code
Handle
CRC
Frame - sync
0xE0
0xA9
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Calibration Data & SFE
Parameters
Handle
CRC
EOF
Pilot tone +
preamble
1 bit [0]
72 bits
16 bits
16 bits
Dummy bit [1]
The content of the Calibration data field and the SFE parameters
field is displayed in the Memory map in “SPI Interface” on
page 45.
Get Battery Level
The GET BATTERY LEVel command starts the AD conversion on
the battery voltage and returns the voltage level with the
battery type (1.5V or 3V).
Command Structure:
SOF
Custom
Command Code
Battery retrigger
Handle
CRC
Frame - sync
0xE0
0xAA
8 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
A/D
Error
Battery
Type
Zeros
Battery
Level
Handle
CRC
EOF
Pilot tone
+
preamble
1 bit [0]
1 bit error [1]
1 bit - [0 =
1.5V, 1 = 3V]
4 bits
[0000]
10 bits
16 bits
16 bits
Dummy
bit [1]
The application can also request the battery type re-check if
the Battery retrigger field has the value “00000001”, otherwise
the Battery retrigger field needs to have the value “00000000”.
SL900A – 36
ams Datasheet: 2014-May-06 [v1-01]
Custom Command Description
Set Shelf Life
The SET SHELF LIFE command programs parameters for the
dynamic shelf life algorithm.
Command Structure:
SOF
Custom
Command Code
SL Block 0
SL Block 1
Handle
CRC
Frame - sync
0xE0
0xAB
32 bits
32 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
The “SL Block 0” field is composed as:
Bit Number
31 … 24
23 … 16
15 … 8
7…0
Function
Tmax [7:0]
Tmin [7:0]
Tstd [7:0]
Ea [7:0]
The “SL Block 1” field is composed as:
Bit Number
31 … 16
15 … 6
5…4
3
2
1…0
Function
SLinit [15:0]
Tinit [9:0]
Shelf life
sensor ID [1:0]
Enable
negative
shelf life
Shelf life
algorithm
enable
RFU [1:0]
Initialize
The INITIALIZE command clears the System status field, the
Limit counters and sets the Delay time field and the Application
data field. The Initialize command is needed before the START
LOG command as it will clear the pointers and counters. If the
application needs to run the logging process from the previous
point on, the Initialize command ca be left out.
Command Structure:
SOF
Custom
Command Code
Delay Time
Application time
Handle
CRC
Frame - sync
0xE0
0xAC
16 bits
16 bits
16 bits
16
bits
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 37
Custom Command Description
Successful Reply Structure:
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
The “Delay Time” field is composed as:
Bit Number
15 … 4
3…2
1
0
Function
Delay time [11:0]
RFU [1:0]
Delay mode [0 – timer, 1 –
external switch]
IRQ+timer enable
The “Application Data” field is composed as:
Bit Number
15 … 7
6…3
2…0
Function
Number of words for application data [8:0]
RFU [3:0]
Broken word pointer [2:0]
Get Sensor Value
The GET SENSOR VALUE command starts the AD conversion on
the specified sensor and returns the value.
Command Structure:
SOF
Custom
Command Code
Sensor Type
Handle
CRC
Frame - sync
0xE0
0xAD
8 bits
16 bits
16 bits
Successful Reply Structure:
SOF
Header
A/D Error
Range/Limit
Sensor Value
Handle
CRC
EOF
Pilot tone +
preamble
1 bit [0]
1 bit - error
[1]
5 bits (1), (2)
10
bits
16
bits
16
bits
Dummy
bit [1]
Note(s) and/or Footnote(s):
1. RANGE - for external sensors
2. LIMIT CURRENT - for self heating compensation.
The “Sensor Type” field is composed as:
Bit Number
Function
SL900A – 38
7…2
RFU [5:0] – all 0’s
1…0
Sensor type:
• 00 – Temperature sensor
• 01 – External sensor 1
• 10 – External sensor 2
• 11 – Battery voltage
ams Datasheet: 2014-May-06 [v1-01]
Custom Command Description
Open Area
The OPEN AREA command opens the specified area (System,
Application, and Measurement) that is protected by a password.
Command Structure:
SOF
Custom
Command Code
Password Level
Password
Handle
CRC
Frame - sync
0xE0
0xAE
8 bits
32 bits
16 bits
16 bits
SOF
Header
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
16 bits
16 bits
Dummy bit [1]
Successful Reply Structure:
The “Password Level” field is composed as:
Password Level Bits
b1
b0
Passw. level
0
0
Not allowed
0
1
System
1
0
Application
1
1
Measurement
Bits b7 - b2 are X
Access FIFO
The ACCESS FIFO command can read and write data from the
FIFO and can also read the FIFO status register.
Command Structure:
SOF
Custom
Command Code
Sub-command
Payload
Handle
CRC
Frame - sync
0xE0
0xAF
8 bits
0 ~ 8 bytes
16 bits
16 bits
Successful Reply Structure:
SOF
Header
Payload
Handle
CRC
EOF
Pilot tone + preamble
1 bit [0]
0 ~ 8 bytes (data from FIFO or
FIFO status register)
16 bits
16 bits
Dummy bit [1]
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 39
Custom Command Description
Possible Subcommand codes are defined as:
Subcommand bits
Function
Comment
7
6
5
1
0
0
Read data from FIFO
The bits 3-0 specify the number of bytes that will
be read from FIFO
1
0
1
Write data to FIFO
The bits 3-0 specify the number of bytes that will
be written to FIFO
1
1
0
Read status register
The FIFO status register is defined as:
Bit #
Function
7
FIFO busy
6
Data ready
5
No data
4
0 – data from SPI, 1 – data from RFID
3
2
1
Number of valid bytes in FIFO register (0000 – FIFO empty, 0001 – 1 byte,
1000 – 8 bytes)
0
Access FIFO command example:
• Frame sync + E0 AF A5 11 22 33 44 55 + Handle + CRC
• This example command will write 5 bytes to the FIFO.
SL900A – 40
ams Datasheet: 2014-May-06 [v1-01]
L o g g i n g Fo r m a t s
The logging format is selected with the SET LOG MODE
command in the “Logging Mode[2:0]” field.
Logging Formats
Figure 23:
Supported Logging Formats
Logging Mode [2:0]
Logging Form
Description
Bit 2
Bit 1
Bit 0
0
0
0
Dense
All values are stored to the measurement area. No additional
time information is stored to the measurement area.
All values that are out of the specified limits are stored to the
measurement area. Limits comparison is done on the
selected sensor (“Verify sensor ID [1:0]”). The measurement
number is stored, additional to the sensor value.
0
0
1
All values out of
limits
0
1
0
RFU
Reserved for future use – this setting is not allowed
0
1
1
Limits crossing
Only the crossing point of each limit boundary is stored.
Limits comparison is done on the selected sensor (“Verify
sensor ID [1:0]”). The measurement number is stored,
additional to the sensor value.
1
0
0
RFU
Reserved for future use – this setting is not allowed
1
0
1
IRQ, EXT1
Interrupt triggered on the EXT1 external sensor input
1
1
0
IRQ, EXT2
Interrupt triggered on the EXT2 external sensor input
1
1
1
IRQ, EXT1, EXT2
Interrupt triggered on the EXT1 and EXT2 external sensor
input
Dense Logging Form
The dense logging form provides maximum usage of the
non-volatile memory space. 8 sensor values are stored into 5
words of memory when only the internal temperature sensor is
used:
Figure 24:
Dense Form - Only Internal Temperature Sensor
Bits
Block #
15
14
13
12
0x00
0x01
0x04
10
9
8
7
6
5
4
Temp. 1
Temp. 3
Temp. 4
Temp. 5
Temp. 7
2
1
0
Temp. 4
Temp. 5
Temp. 6
ams Datasheet: 2014-May-06 [v1-01]
3
Temp. 2
Temp. 2
0x02
0x03
11
Temp. 7
Temp. 8
SL900A – 41
Lo g gi ng For m ats
In case external sensors are used for logging, the chip will use
the following storage format:
Figure 25:
Dense Form with External Sensors
Bits
Block #
15
0x00
1
Range 5 bits
External sensor 1 - 10 bits
0x01
1
Range 5 bits
External sensor 2 - 10 bits
0x02
14
13
12
11
10
9
8
7
Bat. meas. 6 bits
6
5
4
3
2
1
0
Temperature meas. - 10 bits
In the dense logging form, no time information is stored in the
measurement area of the EEPROM in order to maximize the
number of stored sensor values. The real time of a particular
measurement can be calculated by using the Start time and Log
interval.
Out-of-Limits Logging Form
This logging form uses the limits that are set by the user. The
limits can be set with the SET LOG LIMITS command. The storage
data format is the same for the “All values out-of-limits” form
and the “Limits crossing” form.
Figure 26:
Limits Mode with Internal Sensor Only
Bits
Block #
15
14
0x00
13
12
11
10
9
8
7
6
Battery voltage
5
4
3
2
1
0
3
2
1
0
Temperature
0x01
Measurement #
Figure 27:
Limits Mode with External Sensors
Bits
Block #
15
0x00
1
Range 5 bits
External sensor 1 - 10 bits
0x01
1
Range 5 bits
External sensor 2 - 10 bits
0x02
0x03
SL900A – 42
14
13
12
11
Bat. meas. 6 bits
10
9
8
7
6
5
4
Temperature meas. - 10 bits
Measurement #
ams Datasheet: 2014-May-06 [v1-01]
L o g g i n g Fo r m a t s
Interrupt Logging Form
This logging form is used when the interrupts from external
sensors are enabled. In this case, the real time clock is stored
together with the sensor values.
Figure 28:
Interrupt Mode
Bits
Block #
15
14
0x00
1
Range 5 bits
External sensor 1 - 10 bits
0x01
1
Range 5 bits
External sensor 2 - 10 bits
0x02
13
12
11
10
Bat. meas. 6 bits
9
8
7
6
5
4
3
2
1
0
Temperature meas. - 10 bits
0x03
Real time clock - Higher 16 bits
0x04
Real time clock - Lower 16 bits
Note(s) and/or Footnote(s):
1. The interrupt source can either be the external sensor 1, external sensor 2 or both external sensors. The limits are ignored in the
interrupt mode.
Storage Capacity
The storage capacity is the number of measurement points that
can be stored to the EEPROM. It is dependent on the selected
logging form.
Figure 29:
Storage Capacity:
Selected Sensors
Dense
Limits (both modes)
Event Triggered
Only temperature
841
263
175
Temperature + battery
526
263
175
1 External
526
263
175
Temperature + External
263
175
131
Temperature + External + Battery
263
175
131
2 External
263
175
131
Temperature + 2 external
175
131
105
All 4 sensors
175
131
105
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 43
Storage Rule
Storage Rule
The Storage rule defines how the device handles a completely
full Measurement area. The device has 2 storage rules – normal
or rolling.
Normal storage rule
In this storage rule, the logging of new data is stopped when
the memory is completely full. When this happens, the bit 6 in
the Status Flags (Measurement area full) is set to 1 and no new
data is stored to the EEPROM. However, the timer is still active
and the Number of measurements counter will still be
incremented.
Rolling storage rule
In this mode, the device will overwrite the old data with new
data once the measurement area is completely full. When this
happens, the bit 6 (Measurement area full) and bit 5
(Measurement overwritten) in the Status Flags are set to 1 and
the Number of memory replacements counter is incremented.
The new measurement is stored to the beginning of the
Measurement area.
When the dense logging mode with temperature sensor is used
with the rolling storage mode and the memory is overwritten,
the new data is stored from the beginning of the Measurement
area starting with a fresh 5-block 8-measurements super-block.
It does not matter if the last super-block at the end of the
memory was not completed due to the end of the memory.
When more sensors are enabled or the limits mode is used, it
can happen that the last measurement at the end of the
memory can not be written, because there is not enough space.
An example for this is if all 4 sensors are enabled in dense
logging mode. In this case, 1 measurement is 3 blocks long. If
it happens that there are only 2 blocks free in the memory, the
measurement will be written to the beginning of the
Measurement area, so the last 2 blocks are not used.
When the Number of memory replacement counter reaches its
maximum value, the logging is stopped and no new data is
written to the EEPROM. However, the timer will still be active
and the Number of measurements counter will still be
incremented.
SL900A – 44
ams Datasheet: 2014-May-06 [v1-01]
SPI Inter face
Full and unlimited EEPROM access is possible through the SPI
interface. The primary function of the SPI interface is
production calibration and UID programming, but it can also
be used in application, for the data transmission between the
interrogator and a microcontroller attached to the SPI interface.
The chip has a basic arbitration implemented that controls the
EEPROM access from the RFID interface, the automatic data
logger and the SPI interface. The RFID interface has the highest
priority, second is the automatic data logger, and last is the SPI
interface.
SPI Interface
The first 2 bits in the frame are the MODE bits, which define the
SPI operation (00 – Write memory, 01 – Read memory, 10 – Test,
11 – Direct command). The EEPROM address is an 11-bit address
that point to the physical locations in the EEPROM. The write
command can be executed on a single byte, or any number of
successive bytes on a single page (up to 16 bytes). The minimum
number of bytes in the Page write operation is 2. The Read
operation is a continuous operation, so any number of bytes
can be read with a single frame. The address is the starting
address and is automatically incremented in the chip.
The Test MODE is reserved for production testing and cannot
be used in application.
The maximum SCLK frequency is 10MHz at 3V battery supply
(dual cell). With a 1.5V battery supply the maximum frequency
is 2MHz.
Figure 30:
SPI Communication Modes
MODE
EEPROM Address / Command Code
Data
Byte
A15
A14
A13
A12
A11
A10...A0
D7...D0
Write Mode
0
0
0
0
0
Physical EEPROM address
DI7 … DI0
Page Write
Mode
0
0
0
0
1
Physical EEPROM address
DI7 … DI0
...16 data bytes
Read Mode
0
1
0
0
0
Physical EEPROM address
DO7...DO0
...Continuous
read (n*8 bits)
Test Mode
Command
Mode
RESERVED for PRODUCTION
1
1
ams Datasheet: 2014-May-06 [v1-01]
C5...C0
SL900A – 45
SPI Inter face
Figure 31:
SPI Timings
t sc
t ch
t cl
t ds
t dh
Figure 32:
SPI Timing for 3V Supply Voltage
Symbol
Min
Max
Description
tsc
150us
-
SEN to first SCLK rising edge setup time
tch
100ns
-
SCLK high period
tcl
100ns
-
SCLK low period
tds
50ns
-
Data setup time
tdh
50ns
-
Data hold time
Figure 33:
SPI Timing for 1.5V Supply Voltage
Symbol
Min
Max
tsc
150us
-
SEN to first SCLK rising edge setup time
tch
500ns
-
SCLK high period
tcl
500ns
-
SCLK low period
tds
50ns
-
Data setup time
tdh
50ns
-
Data hold time
SL900A – 46
Description
ams Datasheet: 2014-May-06 [v1-01]
SPI Inter face
Figure 34:
SPI Write Mode
A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0
Figure 35:
SPI Read Mode
A10 A9 A8 A7 A6 A5 A4 A3 A2 A1 A0
D7 D6 D5 D4 D3 D2 D1 D0
Figure 36:
SPI Command Mode - Start Log and Stop Log, Reset command
C5 C4 C3 C2 C1 C0
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 47
SPI Inter face
Figure 37:
SPI Command Mode – Get Temperature, Get Ext. Sensor, Get Battery, Read Fifo, Read Remaining Shelf
Life
C5 C4 C3 C2 C1 C0
D7 D6 D5 D4 D3 D2 D1 D0 D7 D6 D5 D4 D3 D2 D1 D0
Figure 38:
SPI Write FIFO Command
Figure 39:
SPI Read FIFO Status Command
SL900A – 48
ams Datasheet: 2014-May-06 [v1-01]
SPI Direct Commands
SPI Direct Commands
Figure 40:
SPI Direct Commands
Command Code
Command
Comment
0x00
Reset command - same
effect as POR
All calibration registers are refreshed from the EEPROM
0x01
Get temperature
After SDATAO signal goes high send additional 16 clock
pulses for conversion data read-out
0x02
Get battery
After SDATAO signal goes high send additional 16 clock
pulses for conversion data read-out
0x03
Get Ext. sensor 1
After SDATAO signal goes high send additional 16 clock
pulses for conversion data read-out
0x04
Get Ext. sensor 2
After SDATAO signal goes high send additional 16 clock
pulses for conversion data read-out
0x05
Start Logging
Starts the timer or IRQ mode - generates the sta_log
pulse signal - the start time has to be written before with
the SPI Write mode
0x06
Stop Logging
Stops the timer or IRQ mode - generates the end_log
pulse signal
0x07
Read FIFO status
Read the FIFO status byte (8-bit)
0x08
Read Remaining shelf life
Reads the remaining shelf life (24-bit)
0x20
Read FIFO
Reads up to 8 bytes from the FIFO
0x21
Write FIFO
Writes up to 8 bytes to the FIFO
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 49
SPI Direct Commands
FIFO
The SL900A device has an integrated 8-byte FIFO register that
can be used for fast data transmission between the RFID reader
and the microcontroller that is connected to the SPI port.
The FIFO status can be determined by reading the FIFO status
register:
Bit #
Function
7
FIFO busy
6
Data ready
5
No data
4
0 – data from SPI, 1 – data from RFID
3
2
1
Number of valid bytes in FIFO register (0000 – FIFO empty, 0001 – 1 byte, 1000
– 8 bytes)
0
The FIFO can be read and written from the SPI and the RFID
interface. From the RFID interface, the ACCESS FIFO command
is used to access the FIFO register and the FIFO status. From the
SPI interface, 3 commands are used – 0x07, 0x20 and 0x21. The
0x07 commands reads the FIFO status byte. Up to 8 bytes can
be read from the FIFO with the 0x20 command and up to 8 bytes
written with the 0x21 command.
SL900A – 50
ams Datasheet: 2014-May-06 [v1-01]
A l t e r n a t e Pa d Fu n c t i o n s
Alternate Pad Functions
Some functions are multiplexed on same pads, so some
functions of the device can not be used in parallel.
Manual Log Start with Button
The SL900A device supports 2 delayed start possibilities for the
logging. Delayed start means that the logging is not started
immediately when the device receives the Start Log command,
but some time after the reception of this command. The
application can set a fixed delay for the logging, or the logging
can be started manually (without a RFID reader).
Figure 41 shows the external push button connection for the
manual delayed start function. The DIN pin has an integrated
pull-down resistor, so the only required external component is
the button. When the DIN pin is connected to V BAT, the logging
will be started.
Figure 41:
Push Button Connection
VBAT
DIN
R=
100k
In order to enable this function, the application needs to set
the “Delay mode” bit to 1. This is done with the “Initialize”
command on page 37
External Shelf Life Alarm Function
The SL900A device can generate an alarm when the Shelf Life
algorithm is used and the shelf life expires. The EXC pin is used
for this function.
This signal can be used as an interrupt on a microcontroller, or
can be directly used to drive a LED diode. The EXC driver
resistance is 400Ω.
Figure 42 shows how to connect an LED diode to the EXC pin.
This is possible only when the transponder uses a 3V battery
supply as most of the LED diodes have a threshold above 1.5V.
Depending on the type of the LED diode, also an external
current-limiting resistor needs to be used.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 51
Alternate Pa d Func ti ons
Figure 42:
LED Connection for Shelf Life Alarm
VBAT
EXC
400 Ohm
VSS
Gnd
The external alarm function is activated automatically when the
Shelf Life algorithm is used. The “sw_ext_en” bit in Calibration
data has to be 0. If the “sw_ext_en” bit is set to 1, the EXC pin
is used for external sensor supply.
SL900A – 52
ams Datasheet: 2014-May-06 [v1-01]
E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )
External Sensor Front-End (SFE)
The SL900A device can process the internal temperature sensor,
the battery voltage and up to 2 external sensors. The result of
the A/D conversion can be logged to the EEPROM or sent
directly back to the interrogator (if the GET SENSOR VALUE
command is used). The external sensors and the integrated
temperature sensor can only be processed in serial manner. This
is done through a multiplex amplifier, as the SL900A device has
only one A/D converter integrated.
Figure 43:
External Sensor Front End
ext_sw
Vbat
2 Predrive
current
1
4
IRQ
5
REFERENCES
SFE CONTROLS
6
9
EXT2
A-D CONVERTER
V-AGC
7
EXT1
11
VREF
I-AGC
S/H
EXC
3
8
Programmable Current
Sources
ARC
TIMING, IRQ
REFERENCE
10
MEMORY
Vbat
shelf_life
SFE Interface
The external sensor interface consists of 4 pads:
• EXT1 – connection for external sensor 1 that can be a
linear-resistive sensor, a DC voltage source (sensor with
external analog processing), capacitive and resistive
sensors with AC driving,
• EXT2 – connection for external sensor 2 that can be a
linear-conductive sensor, a reverse-polarized diode, DC
voltage source with serial resistance or a DC current
source to V SS,
• EXC – supply voltage for the external sensors or a AC signal
source for external sensors that do not allow a DC voltage.
• V REF – reference voltage (Vo2) pin used for capacitive and
resistive sensors with AC excitation.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 53
External Sensor Front-End (SFE)
The SFE can be used for measurements with resistive sensors
with linear resistance or conductance. It can be used for
capacitive sensors and optical sensors (diode). It can also be
used for connecting integrated sensors with voltage output
(high impedance input).
The SFE allows a connection of a resistor bridge sensor
arrangement, where the bridge is supplied by the EXC pad
(battery voltage) and the 2 sensing points are attached to the
EXT1 and EXT2 inputs. The 4th point of the resistive bridge has
to be attached to the V SS point. The AD conversion for the 2
sensing points is done with 2 successive measurements. First
the EXT1 point and next the EXT2 point. The final calculation
has to be done in the application software.
Also a capacitive or resistive sensor that does not allow a DC
voltage can be attached to the SFE. In this case, the sensing
point is the EXT1 input, the AC stimulus signal is provided by
the EXC pin and the V REF pad outputs an adjustable DC
reference voltage.
SFE Interface
Figure 44:
Sensor Front End Setting Bits
SFE Group Bits
Function
Description
rang[4:0]
External sensor 2 range
Resistor feedback ladder – see application note for SFE
seti[4:0]
External sensor 1 range
Current source value – see application note for SFE
00 – linear resistive sensor
01 – high impedance input (voltage follower), bridge
EXT1[1:0]
external sensor 1 type
10 – reserved
11 – capacitive or resistive sensor without DC (AC signal
on EXC pin)
EXT2
external sensor 2 type
0 – linear conductive sensor, opto sensor, current source
sensor
1 - high impedance input (voltage follower), bridge
Range preset
Use preset range
Autorange function is turned off
00 – first selected sensor
Verify sensor ID[1:0]
Sensor used in limit check
(sensor enable bits in log
mode group)
01 – second selected sensor
10 – third selected sensor
11 – fourth selected sensor
SL900A – 54
ams Datasheet: 2014-May-06 [v1-01]
E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )
The external sensor interface has an auxiliary output pin (EXC)
that can be used for supplying the external sensor either with
a constant voltage or with an AC voltage signal (for capacitive
sensor).
Figure 45:
EXC Output Pin Operation
EXC Pin Controls
EXT1 [1:0]
sw_ext_en
stand-by mode
00
0
0
HI-Z
The output drivers are
disconnected
00
0
1
HI-Z
The output drivers are
disconnected
11
X
X
AC signal during external
sensor conversion
Is to be used only with
capacitive sensors
00
1
0
VBAT
The output is connected to
the battery voltage for the
duration of the conversion
00
1
1
HI-Z
The output drivers are
disconnected
00
1
0
VBAT
The output is connected to
the battery voltage for the
duration of the conversion
00
1
1
HI-Z
The output drivers are
disconnected
ams Datasheet: 2014-May-06 [v1-01]
EXC Signal Output
Comment
SL900A – 55
External Sensor Front-End (SFE)
External Sensor 1 Interface
The external sensor 1 interface (EXT1 pin) can be used for
measurements with linear resistive sensors and capacitive
sensors with AC excitation. It can also be used to measure 1
point of a resistive bridge (with the second point connected to
the EXT2 pad).
The processing of an external capacitive sensor without DC
voltage is possible in case an external reference capacitor is
used. The external sensor in this case is excitated with an AC
signal from the EXC pin. The connection for this kind of sensors
is shown on Figure 46.
Figure 46:
External Capacitive Sensor with AC Excitation (EXT1[1:0] = 11)
EXC
SENS
VREF
REF.
CAP.
EXT1
EXT2
VSS
Cap. No_DC
sensor
SL900A – 56
SL900A
ams Datasheet: 2014-May-06 [v1-01]
E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )
The external capacitive sensor in Figure 46 is excitated with a
square wave signal around the reference voltage V REF. The
amplitude of the AC signal is equal to the V REF voltage. Input
AC amplitude:
C REF ⋅ CAP
V EXT1 = V EXC ⋅ -----------------------------------------------------( C REF ⋅ CAP + C SENS )
The selection of the reference capacitor depends on the AD
converter input voltage range. The input AC amplitude V EXT1 at
minimum capacitance C_SENS must be at a maximum AD level:
V AD
– max
= 2 ⋅ V vo2 – V vo1
The input AC amplitude V EXT1 at minimum capacitance C_SENS
must be close to minimum AD level:
V AD
– min
= V vo2
The external sensor interface can also be used for resistive
sensor with linear resistance and with resistive sensor that do
not allow any DC voltage (AC excitation). The connection
diagrams are on Figure 47 and Figure 48.
For a resistive sensor with AC excitation The following relation
is valid:
V VREF
V VREF < V VREF + --------------------------------------------------------- ⋅ R REF ⋅ RES ≤ V VREF + vo1
R R – SENS + R REF ⋅ RES
The proper ratio between sensor and reference resistor can be
chosen to fulfill the upper relation and the range of sensor’s
resistivity.
Figure 47:
External Linear Resistive Sensor (EXT1[1:0] = 00)
EXC
VREF
EXT1
EXT2
VSS
Resistive type
sensor - linear
SL900A
resistance
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 57
External Sensor Front-End (SFE)
An additional external reference resistor has to be used for
processing external resistive sensor with AC excitating.
Figure 48:
External Resistive Sensor with AC Signal (EXT1[1:0] = 11)
EXC
R_SENS
VREF
REF.
RES.
EXT1
EXT2
VSS
Res. No_DC
sensor
SL900A
A resistive bridge has to be connected to both sensor inputs
(Figure 49). The 2 input voltages are converted one after the
other. In automatic logging, both external sensors have to be
enabled. If the resistor bridge is also used with the GET SENSOR
VALUE RFID command, this command has to be sent twice – first
for external sensor 1, second for external sensor 2.
Figure 49:
Resistor Bridge Sensor (EXT1[1:0] = 01, EXT2 = 1)
EXC
VREF
EXT1
EXT2
VSS
External bridge
SL900A
sensor
SL900A – 58
ams Datasheet: 2014-May-06 [v1-01]
E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )
External Sensor 2 Interface
The external sensor 2 interface (EXT2 pin) can be used for
measurements with linear conductive sensors, optical sensors
(diode) and to measure the second point of a resistive bridge
(with the first point connected to the EXT1 pad) (see Figure 49).
The Figure 50 shows the connection diagram for a resistive
sensor with linear conductance (like a pressure sensor).
Figure 50:
External Resistive Sensor - Linear Conductance (EXT2 = 0)
EXC
VREF
EXT1
EXT2
VSS
Resistive type
sensor - linear
conductance SL900A
The EXT2 pad can also be used for measurements with an
optical sensor based on reverse polarized diode current
(Figure 51).
Figure 51:
External Optical Sensor (EXT2 = 0)
EXC
VREF
EXT1
EXT2
VSS
Opto sensor
SL900A
A voltage source output sensor can be connected to the EXT2
pin. This can be used for integrated sensors with an analog
output signal.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 59
External Sensor Front-End (SFE)
Figure 52:
External Voltage Source Sensor (EXT2 = 1)
EXC
VREF
EXT1
EXT2
VSS
Sensor -voltage
source
SL900A
The EXT1 interface can also be used for external current source
output sensors (Figure 53).
Figure 53:
External Current Source Sensor (EXT2 = 0)
EXC
VREF
EXT1
EXT2
VSS
Sensor - current
source
SL900A
External Sensor Interface Settings
The external sensor interface is set up either with the SPI
interface or with RFID custom commands. The commands
required for external sensor operation are: SET LOG MODE, SET
SFE PARAMETERS, SET CALIBRATION DATA and INITIALIZE.
The SET LOG MODE command is used to setup various
parameters required for the automatic logging process. The
command is described in “Set Log Mode” on page 30. If external
sensors are used in the logging process, they have to be enabled
with this command.
The SET SFE PARAMETERS command (“Set SFE Parameters” on
page 33) is used to set up the SFE functionality. The SFE can be
used as an automatic range selection block, for sensors with a
SL900A – 60
ams Datasheet: 2014-May-06 [v1-01]
E x t e r n a l S e n s o r Fr o n t - E n d ( S F E )
wide output range. It can also be used as a fixed gain
preamplifier for sensors with a low output range. In this case,
the user application has to preset the range and enable the
preset values. The preset range has to be selected in case the
internal limits are used with an external sensor.
The EXT1 interface gain is preset with the “seti [4:0]” field. The
EXT2 gain is preset with the “rang [4:0]” field. The preset values
are enabled with the “Autorange Preset” flag.
The external sensor type “EXT1[1:0]” and “EXT2” can be set with
the SET SFE PARAMETERS command. This command is also used
for selecting the sensor (“Verify Sensor ID”) that will be used
with the limits in out of limits logging mode.
The SET CALIBRATION DATA command is used to set up the
supply switch for external sensors (“sw_ext_en”) and to setup
the interrupt voltage level for external sensors (“irlev[1:0]”). The
external sensors can be supplied with the battery voltage from
the EXC pin only during the conversion time. This will save
power compared to a system where the sensor is supplied
directly from the battery. This is especially useful for a resistive
bridge sensor.
The INITIALIZE command is used to setup interrupt and timer
logging modes in parallel (“IRQ + timer enable” flag). This
special logging mode can be used for regular interval-based
sensor sampling combined with the interrupt capability of the
SFE.
External Sensor Interrupt
The external sensor interface can be used for sampling short
events on the EXT1 and EXT2 pins. This can be used for shock
sensors, acceleration sensors and other pulse response sensors.
It is also useful for counting events on the external sensor pins.
The sensors are pre-driven with a small current of 125nA and
are constantly observed with a very low consumption
comparator. The overall current consumption of the interrupt
block is 0.5μA at room temperature. In case the sensor voltage
exceeds the specified threshold (“irlev[1:0]”), the SFE will
generate and IRQ request. This will wake up the whole system
and the sensor data, together with the real time information,
will be logged to the memory.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 61
External Sensor Front-End (SFE)
The interrupt mode is selected with the SET LOG MODE
command with the “Logging Mode[2:0]” field (“Logging
Formats” on page 41). The implemented IRQ modes are:
Figure 54:
IRQ Logging Modes
Bit 2
Bit 1
Bit 0
Logging Form
Description
1
0
1
IRQ, EXT1
Interrupt triggered on the EXT1 external
sensor input
1
1
0
IRQ, EXT2
Interrupt triggered on the EXT2 external
sensor input
1
1
1
IRQ, EXT1, EXT2
Interrupt triggered on the EXT1 and EXT2
external sensor input
Either of the 2 external sensor pads, or both of them, can be
used for generating an interrupt. This function can also be used
for button-triggered measurements, as the user can select
which sensor will be logged during an interrupt event.
The interrupt level can be selected by the application with the
SET CALIBRATION DATA command (“irlev[1:0]”). The setting is
valid for EXT1 and EXT2.
Figure 55:
Sensor Front End Setting Bits
Irlev [1:0]
EXT1 resistive – [MΩ]
EXT2 resistive - [MΩ]
IRQ level - % of
supply voltage
Bit 1
Bit 0
0
0
> 2)}
}
SL900A – 68
ams Datasheet: 2014-May-06 [v1-01]
Memory Map Overview
Memory Map Overview
Figure 62:
Memory Map Overview
Loc. #
Physical
Address
1
0x000
Bank
Bank
Name
Logical
Address
Content
System Password
[31:24]
2
0x001
System Password
[23:16]
3
0x002
System Password
[15:8]
4
0x003
System Password [7:0]
5
0x004
User Password [31:24]
6
0x005
User Password [23:16]
7
0x006
User Password [15:8]
8
0x007
User Password [7:0]
9
0x008
Measurement
Password [31:24]
10
0x009
X
11
0x00A
12
0x00B
13
0x00C
SYSTEM
Measurement
Password [23:16]
Measurement
Password [15:8]
Measurement
Password [7:0]
Group
System Password - read
protect
System Password write protect
User Password - read
protect
User Password - write
protect
Measurement Password
- read protect
Measurement Password
- write protest
Year [5:0]
Month [3:2]
Month [1:0]
14
0x00D
Day [4:0]
Hour [4]
Start time
Hour [3:0]
15
0x00E
Minute [5:2]
Minute [1:0]
16
0x00F
Second [5:0]
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 69
Memory Map Overview
Loc. #
Physical
Address
Bank
Bank
Name
Logical
Address
Content
Group
ad1[4:0] - reference
voltage 1 fine cal.
17
0x010
coars1[2:0] - reference
voltage 1 coarse cal.
ad2[4:0] - reference
voltage 2 fine cal.
18
0x011
coars2[2:0] - reference
voltage 2 coarse cal.
gnd_switch
19
selp12[1:0] - 1.5V
battery POR level
0x012
adf[4:0] - 635mV
reference voltage cal.
20
df[7:0] - timer oscillator
cal.
0x013
sw_ext_en - switched
battery supply for ext.
sensor
21
0x014
X
SYSTEM
selp22[1:0] - 3V battery
POR level
Calibration
irlev[1:0]
ring_cal[4:2] - 1.92MHz
oscillator cal.
ring_cal[1:0]
22
0x015
off_int[6:1] temperature offset
calibration
off_int[0]
reftc[3] - band gap
temperature
coefficient cal.
23
0x016
reftc[2:0] - band gap
temperature
coefficient cal.
exc_res - excitate for
resistive sensors
without DC
RFU[1:0]
SL900A – 70
ams Datasheet: 2014-May-06 [v1-01]
Memory Map Overview
Loc. #
24
Physical
Address
Bank
Bank
Name
Logical
Address
Content
Group
rang[4:0] - ext. sensor 2
range (feedback
resistor)
0x017
seti[4:2] - ext. sensor 1
range (current source)
seti[1:0] - ext. sensor 1
range
SFE parameters
sext1[1:0] - external
sensor 1 type
25
0x018
sext2 - external sensor
2 type
Auto range preset
Verify sensor ID[1:0]
26
27
Extreme lower limit
[9:2]
0x019
0x01A
Extreme lower limit
[1:0]
X
SYSTEM
Lower limit [9:4]
Lower limit [3:0]
28
0x01B
Limits
Upper limit [9:6]
Upper limit [5:0]
29
0x01C
30
0x01D
Extreme upper limit
[7:0]
31
0x01E
Ext. lower limits
counter [7:0]
32
0x01F
Lower limits counter
[7:0]
33
0x020
Higher limits counter
[7:0]
34
0x021
Ext. higher limits
counter [7:0]
Extreme upper limit
[9:8]
Limits counter
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 71
Memory Map Overview
Loc. #
Physical
Address
35
0x022
Bank
Bank
Name
Logical
Address
Content
Group
Measurement address
pointer [9:2]
Measurement address
pointer [1:0]
36
0x023
Number of memory
replacements [5:0]
37
38
System status
Number of
measurements [14:7]
0x024
Number of
measurements [6:0]
0x025
Active
Logging form [2:0]
Storage rule (0 normal, 1 - rolling)
39
0x026
Ext.1 sensor enable
X
SYSTEM
Log mode
Ext.2 sensor enable
Temp. sensor enable
Battery check enable
40
0x027
41
0x028
Log interval [14:7]
Log interval [6:0]
Log interval
RFU
42
0x029
Delay time [11:4]
Delay time [3:0]
Single use flag
43
0x02A
Delay time
RFU
Delay mode (0 - timer
or 1 - switch)
IRQ+timer enable
SL900A – 72
ams Datasheet: 2014-May-06 [v1-01]
Memory Map Overview
Loc. #
Physical
Address
44
0x02B
Bank
Bank
Name
Logical
Address
Content
Number of blocks for
user data [8:1]
Number of blocks for
user data [0]
45
Group
User data
RFU [3:0]
0x02C
Broken word pointer
[2:0]
46
0x02D
RFU[7:0]
RFU
Kill lock [1:0]
Access lock [1:0]
47
0x02E
EPC [1:0]
TID lock [1:0]
Lock bits, write ONLY
with the 'Lock'
command
USER lock [1:0]
48
0x02F
RFU [5:0]
49
0x030
50
0x031
Tmin[7:0]
51
0x032
Tstd[7:0]
52
0x033
Ea[7:0]
53
0x034
SLinit[15:8]
54
0x035
Slinit[7:0]
55
0x036
Tinit[9:2]
X
SYSTEM
Tmax[7:0]
Shelf Life block 0
Tinit[1:0]
ShelfLife Sensor ID
[1:0]
56
0x037
Shelf Life block 1
Enable Negative
ShelfLife
Shelf life algorithm
enable
Skip log [1:0]
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 73
Memory Map Overview
Loc. #
57
58
Physical
Address
Bank
Bank
Name
Logical
Address
Content
Group
T1_delay [3:0]
Adjust bits for the T1
timer (default value is
“0111”
FIRO_enable
Enable FIRO RNG
cl_sh_diss
Disables the clock shop
T2_diss
Disables the T2 timing
RFU
Reserved for future use
RFU[6:0]
Reserved for future use
KILL
KILL flag
0x038
0x039
X
SYSTEM
59
0x03A
RFU[7:0]
60
0x03B
RFU[7:0]
61
0x03C
RFU[7:0]
62
0x03D
RFU[7:0]
63
0x03E
RFU[7:0]
64
0x03F
RFU[7:0]
65
0x040
RFU
Kill Password [31:24]
0x00
66
0x041
Kill Password [23:16]
67
0x042
Kill Password [15:8]
68
0x043
69
0x044
Kill Password
0x01
Kill Password [7:0]
0
Access Password
[31:24]
RESERVED
0x02
70
0x045
71
0x046
Access Password
[23:16]
Access Password
Access Password [15:8]
0x03
72
0x047
Access Password [7:0]
RAM - 1
RAM 0x00
CRC-16 [15:8]
RAM - 2
RAM 0x01
73
0x048
0x00
1
CRC-16 [7:0]
EPC
PC [15:8]
0x01
74
SL900A – 74
0x049
CRC-16 is stored in the
RAM portion and is
mapped to the EPC
memory block
PC
PC [7:0]
ams Datasheet: 2014-May-06 [v1-01]
Memory Map Overview
Loc. #
Physical
Address
75
0x04A
Bank
Bank
Name
Logical
Address
Content
Group
EPC [127:120]
0x02
76
0x04B
77
0x04C
EPC [119:112]
EPC [111:104]
0x03
78
0x04D
79
0x04E
EPC [103:96]
EPC [95:88]
0x04
80
0x04F
81
0x050
EPC [87:80]
EPC [79:72]
0x05
82
0x051
EPC [71:64]
1
83
0x052
84
0x053
85
0x054
EPC
EPC
EPC [63:56]
0x06
EPC [55:48]
EPC [47:40]
0x07
86
0x055
87
0x056
EPC [39:32]
EPC [31:24]
0x08
88
0x057
89
0x058
EPC [23:16]
EPC [15:8]
0x09
90
0x059
91
0x05A
EPC [7:0]
TID [7:0] – 0xE0
0x00
92
0x05B
93
0x05C
TID [15:8] – 0x36
TID [23:16]
0x01
94
0x05D
95
0x05E
TID [31:24]
TID [39:32]
2
96
0x05F
97
0x060
TID
TID (same format as UID
in ISO 15693),
READ ONLY
0x02
TID [47:40]
TID [55:48]
0x03
98
0x061
99
0x062
TID [63:56]
Chip version [7:0]
0x04
100
0x063
ams Datasheet: 2014-May-06 [v1-01]
RFU [7:0]
Version, etc...
READ ONLY
SL900A – 75
Memory Map Overview
Loc. #
Physical
Address
101
0x064
Bank
Bank
Name
Logical
Address
0x000
102
0x065
~
~
~
~
1151
0x47E
1152
0x47F
3
USER
Content
Group
USER memory start UMI
USER / MEASUREMENT
memory – 1052 bytes
~
~
0x20D
SL900A – 76
USER memory end
ams Datasheet: 2014-May-06 [v1-01]
Applications
Applications
Battery-Assisted Transponder – Temperature
Data Logger
In the battery-assisted transponder application, only 4 pads are
used – the antenna pads and the battery pads. This kind of
circuit is suitable for a temperature data logger application.
Dipole
Antenna
16
15
14
13
ANA_TEST
EXC
MEAS
VBAT
Figure 63:
Battery-Assisted Transponder – Temperature Data Logger
1
VPOS
2
VSSA
3
ANT
4
DIGI_TEST
DOUT
12
DIN
11
SCLK
10
SEN
9
Battery
1.5V or 3V
VREF
EXT1
EXT2
VSS
SL900A
5
6
7
8
Passive Transponder – Passive Temperature
Sensor
In the passive transponder, 2 pads are required for the antenna
(ANT, V SSA). For extended read range an external capacitor
connected between the V POS and VSS pads is recommended.
ams Datasheet: 2014-May-06 [v1-01]
VBAT
VSSA
13
MEAS
2
14
EXC
VPOS
15
DOUT
12
DIN
11
SCLK
10
SEN
9
SL900A
DIGI_TEST
VSS
4
EXT2
ANT
EXT1
3
VREF
Dipole
Antenna
1
16
ANA_TEST
Figure 64:
Passive Transponder – Passive Temperature Sensor
5
6
7
8
Optional
External
Capacitor
SL900A – 77
Applications
Battery-Assisted Transponder with External
Microcontroller
An external microcontroller can be connected to the SL900A
device using the SPI interface. The microcontroller can read and
write the EEPROM, start and stop logging, perform an AD
conversion and data can be transmitted to the RFID reader. The
microcontroller can be used to perform additional tasks to
extend the functionality of the system.
Figure 65:
Battery-Assisted Transponder with External Microcontroller
VDD
VBAT
VSSA
13
MEAS
2
14
EXC
VPOS
15
DOUT
12
DIN
DIN
11
DOUT
SCLK
10
SCLK
SEN
9
SEN
SL900A
VSS
DIGI_TEST
EXT2
4
EXT1
ANT
VREF
3
5
6
7
8
μC
VSS
Dipole
Antenna
1
16
ANA_TEST
Battery
1.5V or 3V
Battery-Assisted Transponder with Pushbutton
for Manual Delayed Log Start
In the battery-assisted transponder application, 5 pads are used
– the antenna pads, the battery pads and DIN for push button
input. This kind of circuit is suitable for a temperature data
logger application with manual logging start.
SL900A – 78
VBAT
VSSA
13
MEAS
2
14
EXC
VPOS
15
DOUT
12
DIN
11
SCLK
10
SEN
9
SL900A
DIGI_TEST
VSS
4
EXT2
ANT
EXT1
3
VREF
Dipole
Antenna
1
16
ANA_TEST
Figure 66:
Battery-Assisted Transponder with Pushbutton for Manual Delayed Log Start
5
6
7
8
Battery
1.5V or 3V
ams Datasheet: 2014-May-06 [v1-01]
Applications
Dense Mode Logging – First 8 Measurements
This is a short representation of the Measurement memory, the
address pointer and the measurement counter for dense
logging mode with the integrated temperature sensor. Shown
are only the first 8 measurements – all other measurements are
stored in same manner.
Temperature data is: 0x2AA, 0x3FF, 0x2AA, 0x3FF, …
Figure 67:
Dense Mode Logging – First 8 Measurements:
No Measurement:
0
00000000
00000000
Address pointer
0
1
00000000
00000000
Measurement counter
0
2
00000000
00000000
Broken Word Pointer
0
3
00000000
00000000
4
00000000
00000000
5
00000000
00000000
Measurement 1:
0
10101010
10000000
Address pointer
0
1
00000000
00000000
Measurement counter
1
2
00000000
00000000
Broken Word Pointer
5
3
00000000
00000000
4
00000000
00000000
5
00000000
00000000
Measurement 2:
0
10101010
10111111
Address pointer
1
1
11110000
00000000
Measurement counter
2
2
00000000
00000000
Broken Word Pointer
2
3
00000000
00000000
4
00000000
00000000
5
00000000
00000000
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 79
Applications
Measurement 3:
0
10101010
10111111
Address pointer
1
1
11111010
10101000
Measurement counter
3
2
00000000
00000000
Broken Word Pointer
7
3
00000000
00000000
4
00000000
00000000
5
00000000
00000000
Measurement 4:
0
10101010
10111111
Address pointer
2
1
11111010
10101011
Measurement counter
4
2
11111111
00000000
Broken Word Pointer
4
3
00000000
00000000
4
00000000
00000000
5
00000000
00000000
Measurement 5:
0
10101010
10111111
Address pointer
3
1
11111010
10101011
Measurement counter
5
2
11111111
10101010
Broken Word Pointer
1
3
10000000
00000000
4
00000000
00000000
5
00000000
00000000
Measurement 6:
0
10101010
10111111
Address pointer
3
1
11111010
10101011
Measurement counter
6
2
11111111
10101010
Broken Word Pointer
6
3
10111111
11110000
4
00000000
00000000
5
00000000
00000000
SL900A – 80
ams Datasheet: 2014-May-06 [v1-01]
Applications
Measurement 7:
0
10101010
10111111
Address pointer
4
1
11111010
10101011
Measurement counter
7
2
11111111
10101010
Broken Word Pointer
3
3
10111111
11111010
4
10101000
00000000
5
00000000
00000000
Measurement 8:
0
10101010
10111111
Address pointer
5
1
11111010
10101011
Measurement counter
8
2
11111111
10101010
Broken Word Pointer
0
3
10111111
11111010
4
10101011
11111111
5
00000000
00000000
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 81
Pack age Drawings & Mark ings
Package Drawings & Markings
Figure 68:
Package Drawings
SL900A
Symbol
Min
Nom
Max
A
0.80
0.90
1.00
A1
b
0.203 REF
0.33
0.40
D
5.00 BSC
E
5.00 BSC
0.47
D1
3.15
3.25
3.35
E1
3.15
3.25
3.35
e
-
0.80 BSC
-
L
0.255
0.355
0.455
L1
0.10
P
45º BSC
aaa
0.10
ccc
0.10
SL900A Package Drawings: The reflow peak soldering temperature (body temperature) is specified according
IPC/JEDEC J-STD-020C “Moisture/Reflow Sensitivity Classification for Nonhermetic Solid State Surface Mount
Devices”.
Note(s) and/or Footnote(s):
1. Dimensioning and tolerances conform to ASME Y14.5M-1994.
2. All dimensions are in millimeters. Angles are in degrees.
3. Dimension b applies to metalized terminal and is measured between 0.25mm and 0.30mm from terminal tip. Dimension L1 represents
terminal full back from package edge up to 0.1mm is acceptable.
4. Co-planarity applies to the exposed heat slug as well as the terminal.
5. Radius on terminal is optional.
6. This drawing is subject to change without notice.
SL900A – 82
ams Datasheet: 2014-May-06 [v1-01]
RoHS Compliant & ams Green Statement
RoHS Compliant & ams Green
Statement
RoHS: The term RoHS compliant means that ams products fully
comply with current RoHS directives. Our semiconductor
products do not contain any chemicals for all 6 substance
categories, including the requirement that lead not exceed
0.1% by weight in homogeneous materials. Where designed to
be soldered at high temperatures, RoHS compliant products are
suitable for use in specified lead-free processes.
ams Green (RoHS compliant and no Sb/Br): ams Green
defines that in addition to RoHS compliance, our products are
free of Bromine (Br) and Antimony (Sb) based flame retardants
(Br or Sb do not exceed 0.1% by weight in homogeneous
material).
Important Information: The information provided in this
statement represents ams knowledge and belief as of the date
that it is provided. ams bases its knowledge and belief on
information provided by third parties, and makes no
representation or warranty as to the accuracy of such
information. Efforts are underway to better integrate
information from third parties. ams has taken and continues to
take reasonable steps to provide representative and accurate
information but may not have conducted destructive testing or
chemical analysis on incoming materials and chemicals. ams
and ams suppliers consider certain information to be
proprietary, and thus CAS numbers and other limited
information may not be available for release.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 83
Ordering & Contact Information
Ordering & Contact Information
Figure 69:
Ordering Information
Ordering
Code
SL900A-AQFT
SL900A-ASWB
Description
Smart active label IC with
on-chip temperature
sensor and 9k EEPROM
Operating
Temperature
Range
Package
Type
Device
Marking
-40°C to 125°C
QFN 16
(5 x 5 mm)
SL900A
-40ºC to 125ºC
-
Shipping
Form
Tape & reel
(1,000/reel)
Tested wafers
Ordering Information: Order quantities should be a multiple of shipping form.
Buy our products or get free samples online at:
www.ams.com/ICdirect
Technical Support is available at:
www.ams.com/Technical-Support
For further information and requests, e-mail us at:
ams_sales@ams.com
For sales offices, distributors and representatives, please visit:
www.ams.com/contact
Headquarters
ams AG
Tobelbaderstrasse 30
8141 Unterpremstaetten
Austria, Europe
Tel: +43 (0) 3136 500 0
Website: www.ams.com
SL900A – 84
ams Datasheet: 2014-May-06 [v1-01]
Copyrights & Disclaimer
Copyrights & Disclaimer
Copyright ams AG, Tobelbader Strasse 30, 8141
Unterpremstaetten, Austria-Europe. Trademarks Registered. All
rights reserved. The material herein may not be reproduced,
adapted, merged, translated, stored, or used without the prior
written consent of the copyright owner.
Devices sold by ams AG are covered by the warranty and patent
indemnification provisions appearing in its Terms of Sale. ams
AG makes no warranty, express, statutory, implied, or by
description regarding the information set forth herein. ams AG
reserves the right to change specifications and prices at any
time and without notice. Therefore, prior to designing this
product into a system, it is necessary to check with ams AG for
current information. This product is intended for use in
commercial applications. Applications requiring extended
temperature range, unusual environmental requirements, or
high reliability applications, such as military, medical
life-support or life-sustaining equipment are specifically not
recommended without additional processing by ams AG for
each application. This Product is provided by ams “AS IS” and
any express or implied warranties, including, but not limited to
the implied warranties of merchantability and fitness for a
particular purpose are disclaimed.
ams AG shall not be liable to recipient or any third party for any
damages, including but not limited to personal injury, property
damage, loss of profits, loss of use, interruption of business or
indirect, special, incidental or consequential damages, of any
kind, in connection with or arising out of the furnishing,
performance or use of the technical data herein. No obligation
or liability to recipient or any third party shall arise or flow out
of ams AG rendering of technical or other services.
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 85
Document Status
Document Status
Document Status
Product Preview
Preliminary Datasheet
Datasheet
Datasheet (discontinued)
SL900A – 86
Product Status
Definition
Pre-Development
Information in this datasheet is based on product ideas in
the planning phase of development. All specifications are
design goals without any warranty and are subject to
change without notice
Pre-Production
Information in this datasheet is based on products in the
design, validation or qualification phase of development.
The performance and parameters shown in this document
are preliminary without any warranty and are subject to
change without notice
Production
Information in this datasheet is based on products in
ramp-up to full production or full production which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade
Discontinued
Information in this datasheet is based on products which
conform to specifications in accordance with the terms of
ams AG standard warranty as given in the General Terms of
Trade, but these products have been superseded and
should not be used for new designs
ams Datasheet: 2014-May-06 [v1-01]
Revision Information
Revision Information
Changes from 1-00 (2013-Aug) to current revision 1-01 (2014-May-06)
Page
Removed “Confidential” from footer
ams Datasheet: 2014-May-06 [v1-01]
SL900A – 87
Content Guide
Content Guide
SL900A – 88
1
1
2
2
2
General Description
Key Benefits & Features
Package Options
Applications
Block Diagram
3
4
6
6
6
7
Pin Assignment
Bare Die Pad Layout
Absolute Maximum Ratings
Electrical Discharge Sensitivity
Operating Conditions
Electrical Characteristics
9
10
10
10
11
11
11
11
11
11
12
12
12
Short Description
Supply Arrangement
Analog Front End (AFE)
Processing and Digital Control
Serial Interface (SPI)
Real-Time Clock (RTC)
Temperature Sensor
External Sensors
Analog to Digital Converter
External Sensor Interrupt
Data Protection
Shelf Life
Memory arrangement
13
13
13
13
13
13
13
13
14
15
16
17
18
18
18
21
21
System Description
Initializing the Chip
Power Modes
Ready Mode
Active Mode
Logging Mode
Interrupt Mode
Stand-by Mode
State Diagram
Data Protection
Data Log Functions
Limits Counter
Logging Timer
Delay Time
Analog to Digital Conversion
Temperature Conversion
Battery Voltage Conversion
22
25
25
25
25
25
25
25
25
Commands
Supported EPC Gen2 Commands
QuerryREP - #01
ACK - #02
Query - #03
QueryAdjust - #04
Select - #05
NAK - #06
Req_RN - #07
ams Datasheet: 2014-May-06 [v1-01]
Content Guide
ams Datasheet: 2014-May-06 [v1-01]
25
26
26
26
26
26
26
27
27
27
27
27
27
27
27
28
28
28
28
28
28
28
28
28
Read - #08
Write - #09
Kill - #10
Lock - #11
Access - #12
BlockWrite - #13
BlockErase - #14
Cool-Log Custom Commands
Set Password - #15
Set Log Mode - #16
Set Log Limits - #17
Get Measurement Setup - #18
Set SFE Parameters - #19
Set Calibration Data - #20
End Log - #21
Start Log - #22
Get Log State - #23
Get Calibration Data - #24
Get Battery Level - #25
Set Shelf Life - #26
Initialize - #27
Get Sensor Value - #28
Open Area - #29
Access FIFO - #30
29
30
30
31
31
33
33
34
34
35
36
36
37
37
38
39
39
Custom Command Description
Set Password
Set Log Mode
Set Log Limits
Get Measurement Setup
Set SFE Parameters
Set Calibration Data
End Log
Start Log
Get Log State
Get Calibration Data
Get Battery Level
Set Shelf Life
Initialize
Get Sensor Value
Open Area
Access FIFO
41
41
42
43
43
Logging Formats
Dense Logging Form
Out-of-Limits Logging Form
Interrupt Logging Form
Storage Capacity
44
44
44
Storage Rule
Normal storage rule
Rolling storage rule
45
SPI Interface
SL900A – 89
Content Guide
49
50
SPI Direct Commands
FIFO
51
51
51
Alternate Pad Functions
Manual Log Start with Button
External Shelf Life Alarm Function
53
53
54
56
59
60
61
External Sensor Front-End (SFE)
SFE Interface
SFE Interface
External Sensor 1 Interface
External Sensor 2 Interface
External Sensor Interface Settings
External Sensor Interrupt
63
Calibration Bits
64
65
Shelf Life Calculation
Shelf Life Sensor ID [1:0]
69
Memory Map Overview
77
77
79
Applications
Battery-Assisted Transponder – Temperature
Data Logger
Passive Transponder – Passive Temperature Sensor
Battery-Assisted Transponder with
External Microcontroller
Battery-Assisted Transponder with Pushbutton for
Manual Delayed Log Start
Dense Mode Logging – First 8 Measurements
82
83
84
85
Package Drawings and Markings
RoHS Compliant & ams Green Statement
Ordering & Contact Information
Copyrights & Disclaimer
77
78
78
SL900A – 90
ams Datasheet: 2014-May-06 [v1-01]
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