SE98A
DDR memory module temp sensor, 1.7 V to 3.6 V
Rev. 04 — 25 November 2009
Product data sheet
1. General description
The NXP Semiconductors SE98A measures temperature from −40 °C and +125 °C with
JEDEC Grade B ±1 °C accuracy between +75 °C and +95 °C communicating via the
I2C-bus/SMBus. It is typically mounted on a Dual In-Line Memory Module (DIMM)
measuring the DRAM temperature in accordance with the new JEDEC (JC-42.4) Mobile
Platform Memory Module Thermal Sensor Component specification.
The SE98A thermal sensor operates over the VDD range of 1.7 V to 3.6 V. The SE98A
does not include the 2 k SPD and is designed for custom DIMM where larger SPD is
required.
The Temp Sensor (TS) consists of an Analog-to-Digital Converter (ADC) that monitors
and updates its own temperature readings 8 times per second, converts the reading to a
digital data, and latches them into the data temperature registers. User-programmable
registers, such as Shutdown or Low-power modes and the specification of temperature
event and critical output boundaries, provide flexibility for DIMM temperature-sensing
applications.
When the temperature changes beyond the specified boundary limits, the SE98A outputs
an EVENT signal using an open-drain output that can be pulled up between 0.9 V and
3.6 V. The user has the option of setting the EVENT output signal polarity as either an
active LOW or active HIGH comparator output for thermostat operation, or as a
temperature event interrupt output for microprocessor-based systems. The EVENT output
can even be configured as a critical temperature output.
The SE98A supports the industry-standard 2-wire I2C-bus/SMBus serial interface. The
SMBus TIMEOUT function is supported to prevent system lock-ups. Manufacturer and
Device ID registers provide the ability to confirm the identify of the device. Three address
pins allow up to eight devices to be controlled on a single bus.
The SE98A is an improved SE98 and is comparable to the thermal sensor in the SE97 but
with voltage range of 1.7 V to 3.6 V.
2. Features
JEDEC (JC-42.4) TS3000B1 DIMM ± 0.5 °C (typ.) between 75 °C and 95 °C
temperature sensor
Optimized for voltage range: 1.7 V to 3.6 V
Shutdown current: 0.1 μA (typ.) and 5.0 μA (max.)
2-wire interface: I2C-bus/SMBus compatible, 0 Hz to 400 kHz
SMBus ALERT and TIMEOUT (programmable)
11-bit ADC Temperature-to-Digital converter with 0.125 °C resolution
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
Operating current: 250 μA (typ.) and 400 μA (max.)
Programmable hysteresis threshold: 0 °C, 1.5 °C, 3 °C, 6 °C
Over/under/critical temperature EVENT output
B grade accuracy:
±0.5 °C/±1 °C (typ./max.) → +75 °C to +95 °C
±1 °C/±2 °C (typ./max.) → +40 °C to +125 °C
±2 °C/±3 °C (typ./max.) → −40 °C to +125 °C
ESD protection exceeds 2000 V HBM per JESD22-A114, 250 V MM per
JESD22-A115, and 1000 V CDM per JESD22-C101
Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
Available packages: TSSOP8, HWSON8 (PSON8 VCED-3) and HXSON8
3. Applications
DDR2 and DDR3 memory modules
Laptops, personal computers and servers
Enterprise networking
Hard disk drives and other PC peripherals
4. Ordering information
Table 1.
Ordering information
Type number
Topside
mark
Package
Name
Description
Version
SE98APW
S98A
TSSOP8
plastic thin shrink small outline package; 8 leads;
body width 4.4 mm
SOT530-1
SE98ATP[1]
98A
HWSON8
plastic thermal enhanced very very thin small outline package;
no leads; 8 terminals; body 2 × 3 × 0.8 mm
SOT1069-2
SE98ATL
8AL
HXSON8
plastic thermal enhanced extremely thin small outline package;
no leads; 8 terminals; body 2 × 3 × 0.5 mm
SOT1052-1
[1]
Industry standard 2 mm × 3 mm × 0.8 mm package to JEDEC VCED-3 PSON8 in 8 mm × 4 mm pitch tape 4 k quantity reels.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
2 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
5. Block diagram
SE98A
TEMPERATURE REGISTER
CRITICAL ALARM TRIP
UPPER ALARM TRIP
LOWER ALARM TRIP
POR
VDD
BAND GAP
TEMPERATURE
SENSOR
VSS
11-BIT ΔΣ ADC
CAPABILITY
EVENT
MANUFACTURING ID
DEVICE/REV ID
SMBus/I2C-BUS
INTERFACE
SCL
SDA
FILTER
SMBus TIMEOUT/ALERT
CONFIGURATION
•
•
•
•
•
•
•
10 V
OVERVOLTAGE
HYSTERESIS
SHUT DOWN TEMP SENSOR
LOCK PROTECTION
EVENT OUTPUT ON/OFF
EVENT OUTPUT POLARITY
EVENT OUTPUT STATUS
CLEAR EVENT OUTPUT STATUS
A0
R
30 kΩ to 800 kΩ
A1
R
30 kΩ to 800 kΩ
A2
POINTER REGISTER
R
30 kΩ to 800 kΩ
002aad756
Fig 1.
Block diagram of SE98A
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
3 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
6. Pinning information
6.1 Pinning
terminal 1
index area
1
A1
2
A0
8
VDD
A1
2
7
EVENT
A2
3
6
SCL
VSS
4
5
VDD
7
EVENT
SDA
A2
3
6
SCL
VSS
4
5
SDA
002aaf008
Transparent top view
002aad757
Fig 2.
8
SE98ATP
1
SE98APW
A0
Pin configuration for TSSOP8
Fig 3.
Pin configuration for HWSON8
SE98ATL
terminal 1
index area
A0
1
8
VDD
A1
2
7
EVENT
A2
3
6
SCL
VSS
4
5
SDA
002aad910
Transparent top view
Fig 4.
Pin configuration for HXSON8
6.2 Pin description
Table 2.
Pin description
Symbol
Pin
Type
Description
A0[1]
1
I
I2C-bus/SMBus slave address bit 0 with internal pull-down
A1
2
I
I2C-bus/SMBus slave address bit 1 with internal pull-down
A2
3
I
I2C-bus/SMBus slave address bit 2 with internal pull-down
VSS
4
ground
device ground
SDA
5
I/O
SMBus/I2C-bus serial data input/output (open-drain).
Must have external pull-up resistor.
SCL
6
I
SMBus/I2C-bus serial clock input/output (open-drain).
Must have external pull-up resistor.
EVENT
7
O
Thermal alarm output for high/low and critical temperature
limit (open-drain). Must have external pull-up resistor.
VDD
8
power
device power supply (1.7 V to 3.6 V)
[1]
This input is overvoltage tolerant to support software write protection when applied to SPD.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
4 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
7. Functional description
7.1 Serial bus interface
The SE98A uses the 2-wire serial bus (I2C-bus/SMBus) to communicate with a host
controller. The serial bus consists of a clock (SCL) and data (SDA) signals. The device
can operate on either the I2C-bus Standard/Fast mode or SMBus. The I2C-bus
Standard-mode is defined to have bus speeds from 0 Hz to 100 kHz, I2C-bus Fast-mode
from 0 Hz to 400 kHz, and the SMBus is from 10 kHz to 100 kHz. The host or bus master
generates the SCL signal, and the SE98A uses the SCL signal to receive or send data on
the SDA line. Data transfer is serial, bidirectional, and is one bit at a time with the Most
Significant Bit (MSB) transferred first, and a complete I2C-bus data is 1 byte. Since SCL
and SDA are open-drain, pull-up resistors must be installed on these pins.
7.2 Slave address
The SE98A uses a 4-bit fixed and 3-bit programmable (A0, A1 and A2) 7-bit slave address
that allows a total of eight devices to coexist on the same bus. The input of each pin is
sampled at the start of each I2C-bus/SMBus access. The A0, A1 and A2 pins are pulled
LOW internally. The A0 pin is also overvoltage tolerant, supporting 10 V software write
protection when applied to the SPD that shares common address lines.
slave address
R/W
MSB
0
LSB
0
1
1
A2
fixed
A1
A0
X
hardware
selectable
002aab304
Fig 5.
Slave address
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
5 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
7.3 EVENT output condition
The EVENT output indicates conditions such as the temperature crossing a predefined
boundary. The EVENT modes are very configurable and selected using the configuration
register (CONFIG). The interrupt mode or comparator mode is selected using CONFIG[0],
using either TCRIT/UPPER/LOWER or TCRIT only temperature bands (CONFIG[2]) as
modified by hysteresis (CONFIG[10:9]). The UPPER/LOWER (CONFIG[6]) and TCRIT
(CONFIG[7]) bands can be locked. Figure 6 shows an example of the measured
temperature versus time, with the corresponding behavior of the EVENT output in each of
these modes.
Upon device power-up, the default condition for the EVENT output is high-impedance to
prevent spurious or unwanted alarms, but can be later enabled (CONFIG[3]). EVENT
output polarity can be set to active HIGH or active LOW (CONFIG[1]). EVENT status can
be read (CONFIG[4]) and cleared (CONFIG[5]).
• Advisory notification:
– NXP device: After power-up, bit 3 (1) and bit 2 or bit 0 (leave as 0 or 1) can be set
at the same time (e.g., in same byte) but once bit 3 is set (1) then changing bit 2 or
bit 0 has no effect on the device operation.
– Competitor device: Does not require that bit 3 be cleared (e.g., set back to (0))
before changing bit 2 or bit 0.
– Work-around: In order to change bit 2 or bit 0 once bit 3 (1) is set, bit 3 (0) must be
cleared in one byte and then change bit 2 or bit 0 and reset bit 3 (1) in the next
byte.
– SE98B will allow bit 2 or bit 0 to be changed even if bit 3 is set.
If the device enters Shutdown mode (CONFIG[8]) with asserted EVENT output, the output
remains asserted during shutdown.
7.3.1 EVENT pin output voltage levels and resistor sizing
The EVENT open-drain output is typically pulled up to a voltage level from 0.9 V to 3.6 V
with an external pull-up resistor, but there is no real lower limit on the pull-up voltage for
the EVENT pin since it is simply an open-drain output. It could be pulled up to 0.1 V and
would not affect the output. From the system perspective, there will be a practical limit.
That limit will be the voltage necessary for the device monitoring the interrupt pin to detect
a HIGH on its input. A possible practical limit for a CMOS input would be 0.4 V. Another
thing to consider is the value of the pull-up resistor. When a low supply voltage is applied
to the drain (through the pull-up resistor) it is important to use a higher value pull-up
resistor, to allow a larger maximum signal swing on the EVENT pin.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
6 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
Tth(crit) − Thys
temperature (°C)
critical
Ttrip(u) − Thys
Ttrip(u) − Thys
Upper Boundary Alarm
Tamb
Ttrip(l) − Thys
Lower Boundary Alarm
Ttrip(l) − Thys
time
EVENT in Comparator mode
EVENT in Interrupt mode
software interrupt clear
EVENT in ‘Critical Temp only’ mode
(1)
(2)
(1) (3)
(4)
(3)(5)
*
(6) (4)
(2)
002aae324
Refer to Table 3 for figure note information.
Fig 6.
Table 3.
EVENT output condition
EVENT output condition
Figure
note
EVENT output boundary
conditions
(1)
EVENT output
Temperature Register Status bits
Comparator
mode
Interrupt
mode
Critical Temp
only mode
Bit 15
Above
Critical
Trip
Bit 14
Above
Alarm
Window
Bit 13
Below
Alarm
Window
Tamb ≥ Ttrip(l)
H
L
H
0
0
0
(2)
Tamb < Ttrip(l) − Thys
L
L
H
0
0
1
(3)
Tamb > Ttrip(u)
L
L
H
0
1
0
(4)
Tamb ≤ Ttrip(u) − Thys
H
L
H
0
0
0
(5)
Tamb ≥ Tth(crit)
L
L
L
1
1
0
(6)
Tamb < Tth(crit) − Thys
L
H
H
0
1
0
When Tamb ≥ Tth(crit) and Tamb < Tth(crit) − Thys the EVENT output is in Comparator mode
and bit 0 of CONFIG (EVENT output mode) is ignored.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
7 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
7.3.2 EVENT thresholds
7.3.2.1
Alarm window
The device provides a comparison window with an UPPER trip point and a LOWER trip
point, programmed through the Upper Boundary Alarm Trip register (02h), and Lower
Boundary Alarm Trip register (03h). The Upper Boundary Alarm Trip register holds the
upper temperature trip point, while the Lower Boundary Alarm Trip register holds the lower
temperature trip point as modified by hysteresis as programmed in the Configuration
register. When enabled, the EVENT output triggers whenever entering or exiting (crossing
above or below) the alarm window.
• Advisory notification:
– NXP device: The EVENT output can be cleared through the Clear EVENT bit
(CEVNT) or SMBus ALERT.
– Competitor device: The EVENT output can be cleared only through the
Clear EVENT bit (CEVNT).
– Work-around: Only clear EVENT output using the Clear EVENT bit (CEVNT).
– There will be no change to the NXP device.
The Upper Boundary Alarm Trip should always be set above the Lower Boundary Alarm
Trip.
• Advisory notification:
– NXP device: Requires one conversion cycle (125 ms) after setting the alarm
window before comparing the alarm limit with temperature register to ensure that
there is correct data in the temperature register before comparing with the Alarm
Window and operating EVENT output.
– Competitor devices: Compares the alarm limit with temperature register at any
time, so they get the EVENT output immediately when new UPPER or LOWER
Alarm Windows and the EVENT output are set at the same time.
– Work-around: Wait at least 125 ms before enabling EVENT output (EOCTL = 1).
– SE98B will compare alarm window and temperature register immediately after
setting.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
8 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
7.3.2.2
Critical trip
The Tth(crit) temperature setting is programmed in the Critical Alarm Trip register (04h) as
modified by hysteresis as programmed in the Configuration register. When the
temperature reaches the critical temperature value in this register (and EVENT is
enabled), the EVENT output asserts and cannot be de-asserted until the temperature
drops below the critical temperature threshold. The EVENT cannot be cleared through the
Clear EVENT bit (CEVNT) or SMBus ALERT.
The Critical Alarm Trip should always be set above the Upper Boundary Alarm Trip.
• Advisory notification:
– NXP device: Requires one conversion cycle (125 ms) after setting the Alarm
Window before comparing the alarm limit with temperature register to ensure that
there is correct data in the temperature register before comparing with the Alarm
Window and operating EVENT output.
– Competitor devices: Compares the Alarm Window with temperature register at any
time, so they get the EVENT output immediately when new Tth(crit) and
EVENT output are set at the same time.
– Work-around: Wait at least 125 ms before enabling EVENT output (EOCTL = 1).
Intel will change Nehalem BIOS so that Tth(crit) is set for more than 125 ms before
EVENT output is enabled and Event value is checked.
1. Set Tth(crit).
2. Doing something else (make sure that exceeds 125 ms).
3. Enable the EVENT output (EOCTL = 1).
4. Wait 20 μs.
5. Read Event value.
– SE98B will compare Alarm Window and temperature register immediately after
setting.
7.3.3 Event operation modes
7.3.3.1
Comparator mode
In comparator mode, the EVENT output behaves like a window-comparator output that
asserts when the temperature is outside the window (e.g., above the value programmed in
the Upper Boundary Alarm Trip register or below the value programmed in the Lower
Boundary Alarm Trip register or above the Critical Alarm Trip resister if Tth(crit) only is
selected). Reads/writes on the registers do not affect the EVENT output in comparator
mode. The EVENT signal remains asserted until the temperature goes inside the alarm
window or the window thresholds are reprogrammed so that the current temperature is
within the alarm window.
The comparator mode is useful for thermostat-type applications, such as turning on a
cooling fan or triggering a system shutdown when the temperature exceeds a safe
operating range.
7.3.3.2
Interrupt mode
In interrupt mode, EVENT asserts whenever the temperature crosses an alarm window
threshold. After such an event occurs, writing a 1 to the Clear EVENT bit in the
configuration register de-asserts the EVENT output until the next trigger condition occurs.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
9 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
In interrupt mode, EVENT asserts when the temperature crosses the alarm upper
boundary. If the EVENT output is cleared and the temperature continues to increase until
it crosses the critical temperature threshold, EVENT asserts again. Because the
temperature is greater than the critical temperature threshold, a Clear EVENT command
does not clear the EVENT output. Once the temperature drops below the critical
temperature, EVENT de-asserts immediately.
• Advisory notification:
– NXP device: If the EVENT output is not cleared before the temperature goes
above the critical temperature threshold EVENT de-asserts immediately when
temperature drops below the critical temperature.
– Competitor devices: If the EVENT output is not cleared before or when the
temperature is in the critical temperature threshold, EVENT will remain asserted
after the temperature drops below the critical temperature until a Clear EVENT
command.
– Work-around: Always clear the EVENT output before temperature exceeds the
critical temperature.
– SE98B will keep EVENT asserted after the temperature drops below the critical
temperature until a Clear EVENT command de-asserts EVENT.
7.4 Conversion rate
The conversion time is the amount of time required for the ADC to complete a
temperature measurement for the local temperature sensor. The conversion rate is the
inverse of the conversion period which describes the number of cycles the temperature
measurement completes in one second—the faster the conversion rate, the faster the
temperature reading is updated. The SE98A’s conversion rate is at least 8 Hz or 125 ms.
7.4.1 What temperature is read when conversion is in progress
The SE98A has been designed to ensure a valid temperature is always available. When a
read to the temperature register is initiated through the SMBus, the device checks to see if
the temperature conversion process (Analog-to-Digital conversion) is complete and a new
temperature is available:
• If the temperature conversion process is complete, then the new temperature value is
sent out on the SMBus.
• If the temperature conversion process in not complete, then the previous temperature
value is sent out on the SMBus.
It is possible that while the SMBus Master is reading the temperature register, a new
temperature conversion completes. However, this will not affect the data (MSB or LSB)
that is being shifted out. On the next read of the temperature register the new temperature
value will be shifted out.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
10 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
7.5 Power-up default condition
After power-on, the SE98A is initialized to the following default condition:
•
•
•
•
•
Starts monitoring local sensor
EVENT register is cleared—EVENT output is pulled HIGH by external pull-ups
EVENT hysteresis is defaulted to 0 °C
Command pointer is defaulted to ‘00h’
Critical Temp, Alarm Temperature Upper and Lower Boundary Trip register are
defaulted to 0 °C
• Capability register is defaulted to ‘0037h’ for the B-grade and VHV capability
• Operational mode: comparator
• SMBus register is defaulted to ‘00h’
7.6 Device initialization
SE98A temperature sensors have programmable registers, which, upon power-up, default
to zero. The open-drain EVENT output is default to being disabled, comparator mode and
active LOW. The alarm trigger registers default to being unprotected. The configuration
registers, upper and lower alarm boundary registers and critical temperature window are
defaulted to zero and need to be programmed to the desired values. SMBus TIMEOUT
feature defaults to being enabled and can be programmed to disable. These registers are
required to be initialized before the device can properly function. Except for the SPD,
which does not have any programmable registers, and does not need to be initialized.
Table 4 shows the default values and the example value to be programmed to these
registers.
Table 4.
Registers to be initialized
Register
Default value
Example value
Description
01h
0000h
0209h
Configuration register
•
•
•
02h
0000h
0550h
EVENT output = Interrupt mode
EVENT output is enabled
Upper Boundary Alarm Trip register = 85 °C
03h
0000h
1F40h
Lower Boundary Alarm Trip register = −20 °C
04h
0000h
05F0h
Critical Alarm Trip register = 95 °C
22h
0000h
0000h
SMBus register = no change
SE98A_4
Product data sheet
hysteresis = 1.5 °C
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
11 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
7.7 SMBus Time-out
The SE98A supports the SMBus time-out feature. If the host holds SCL LOW between
25 ms and 35 ms, the SE98A would reset its internal state machine to the bus idle state to
prevent the system bus hang-up. This feature is turned on by default. The SMBus time-out
is disabled by writing a logic 1 to bit 7 of register 22h.
Remark: When SMBus time-out is enabled, the I2C-bus minimum bus speed is limited by
the SMBus time-out timer, and goes down to only 10 kHz.
The SE98A has no SCL driver, so it cannot hold the SCL line LOW.
Remark: SMBus time-out works over the entire supply range of 1.7 V to 3.6 V unless
shutdown bit (SHMD) is set and turns off the oscillator.
7.8 SMBus ALERT
The SE98A supports SMBus ALERT when it is programmed for the Interrupt mode and
when the EVENT polarity bit is set to logic 0. The EVENT pin can be ANDed with other
EVENT or ALERT signals from other slave devices to signal their intention to
communicate with the host controller. When the host detects EVENT or ALERT signal
LOW, it issues an Alert Response Address (ARA) to which a slave device would respond
with its address. When there are multiple slave devices generating an ALERT the SE98A
performs bus arbitration. If it wins the bus, it responds to the ARA and then clears the
EVENT pin.
Remark: Either in comparator mode or when the SE98A crosses the critical temperature,
the host must also read the EVENT status bit and provide remedy to the situation by
bringing the temperature to within the alarm window or below the critical temperature if
that bit is set. Otherwise, the EVENT pin will not get de-asserted.
Remark: In the SE98A, the ARA is set to default ON. However, in the SE98B the ARA will
be set to default OFF since ARA is not anticipated to be used in DDR3 DIMM applications.
read
START bit
S
host detects
SMBus ALERT
Fig 7.
0
acknowledge
not acknowledge
Alert Response Address
0
0
1
1
0
STOP bit
device address
0
master sends a START bit,
ARA and a read command
1
0
0
0
1
1
A2
A1
Slave acknowledges and
sends its slave address.
The last bit of slave address
is hard coded '0'.
A0
0
1
P
host NACK and
sends a STOP bit
002aab330
How SE98A responds to SMBus ALERT
SE98A_4
Product data sheet
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Rev. 04 — 25 November 2009
12 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
7.9 SMBus/I2C-bus interface
The data registers in this device are selected by the Pointer register. At power-up, the
Pointer register is set to ‘00’, the location for the Capability register. The Pointer register
latches the last location it was set to. Each data register falls into one of three types of
user accessibility:
• Read only
• Write only
• Write/Read same address.
A ‘write’ to this device will always include the address byte and the pointer byte. A write to
any register other than the Pointer register requires two data bytes.
Reading this device can take place either of two ways:
• If the location latched in the Pointer register is correct (most of the time it is expected
that the Pointer register will point to one of the Temperature register (as it will be the
data most frequently read), then the read can simply consist of an address byte,
followed by retrieving the two data bytes.
• If the Pointer register needs to be set, then an address byte, pointer byte,
repeat START, and another address byte will accomplish a read.
The data byte has the most significant bit first. At the end of a read, this device can accept
either Acknowledge (ACK) or No Acknowledge (NACK) from the Master (No Acknowledge
is typically used as a signal for the slave that the Master has read its last byte). It takes
this device 125 ms to measure the temperature. Refer to the timing diagrams in Figure 8,
Figure 9, Figure 10 and Figure 11 on how to program the device.
1
2
3
4
5
6
7
A6
A5
A4
A3
A2
A1
A0
8
9
W
A
1
2
3
4
5
6
7
8
D7
D6
D5
D4
D3
D2
D1
D0
9
SCL
SDA
S
START
device address and write
ACK
by device
A
register address
P
ACK
STOP
by device
002aab308
A = ACK = Acknowledge bit. W = Write bit = 0. R = Read bit = 1.
Fig 8.
SMBus/I2C-bus write to the Pointer register
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
13 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
(cont.)
SCL
A6
SDA
A5
A4
A3
A2
A1
D7
A0
S
W
device address and write
START
by host
1
2
3
4
5
6
7
D15
D14
D13
D12
D11
D10
D9
D6
D5
D4
D3
D2
D1
(cont.)
D0
A
A
ACK
by device
8
9
1
write register address
2
3
4
5
6
7
D6
D5
D4
D3
D2
D1
ACK
by device
8
9
SCL
SDA
D7
D8
D0
A
most significant byte data
by host
P
A
least significant byte data
ACK
by device
STOP
ACK
by device by host
002aab412
A = ACK = Acknowledge bit. W = Write bit = 0. R = Read bit = 1.
Fig 9.
SMBus/I2C-bus write to the Pointer register followed by a write data word
1
2
3
4
5
6
7
8
9
1
2
3
4
5
6
7
8
9
(cont.)
SCL
A6
SDA
A5
A4
A3
A2
A1
D7
A0
S
W
device address and write
START
by host
1
2
3
4
5
D6
D5
7
8
D3
D2
D1
(cont.)
D0
A
read register address
ACK
by device
6
D4
A
ACK
by device
9
(cont.)
SCL
A6
SDA
A5
A4
A3
A2
A1
repeated
START
by host
(cont.)
A0
SR
R
device address and read
A
ACK
by device
1
2
3
4
5
6
7
8
D15
D14
D13
D12
D11
D10
D9
D8
9
1
2
3
4
5
6
7
8
D7
D6
D5
D4
D3
D2
D1
D0
9
SCL
SDA
A
returned most significant byte data
ACK
by host
NA
returned least significant byte data
P
NACK STOP
by host by host
002aab413
A = ACK = Acknowledge bit. NA = Not Acknowledge bit. W = Write bit = 0. R = Read bit = 1.
Fig 10. SMBus/I2C-bus write to Pointer register followed by a repeat START and an immediate data word read
SE98A_4
Product data sheet
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Rev. 04 — 25 November 2009
14 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
1
2
3
4
5
6
7
8
9
(cont.)
SCL
A6
SDA
A5
A4
A3
A2
A1
(cont.)
A0
R
S
device address and read
START
by host
A
ACK
by device
1
2
3
4
5
6
7
8
D15
D14
D13
D12
D11
D10
D9
D8
9
1
2
3
4
5
6
7
8
D7
D6
D5
D4
D3
D2
D1
D0
9
SCL
SDA
A
returned most significant byte data
ACK
by host
NA
returned least significant byte data
P
NACK STOP
by host
002aab414
A = ACK = Acknowledge bit. NA = Not Acknowledge bit. W = Write bit = 0. R = Read bit = 1.
Fig 11. SMBus/I2C-bus word read from register with a pre-set pointer
7.10 Hot plugging
The SE98A can be used in hot plugging applications. Internal circuitry prevents damaging
current backflow through the device when it is powered down, but with the I2C-bus,
EVENT or address pins still connected. The open-drain SDA and EVENT pins (SCL and
address pins are input only) effectively places the outputs in a high-impedance state
during power-up and power-down, which prevents driver conflict and bus contention. The
50 ns noise filter will filter out any insertion glitches from the state machine, which is very
robust and not prone to false operation.
The device needs a proper power-up sequence to reset itself, not only for the device
I2C-bus and I/O initial states, but also to load specific pre-defined data or calibration data
into its operational registers. The power-up sequence should occur correctly with a fast
ramp rate and the I2C-bus active. The SE98A might not respond immediately after
power-up, but it should not damage the part if the power-up sequence is abnormal. If the
SCL line is held LOW, the part will not exit the power-on reset mode since the part is held
in reset until SCL is released.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
15 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8. Register descriptions
8.1 Register overview
This section describes all the registers used in the SE98A. The registers are used for
latching the temperature reading, storing the low and high temperature limits, configuring,
the hysteresis threshold and the ADC, as well as reporting status. The device uses the
Pointer register to access these registers. Read registers, as the name implies, are used
for read only, and the write registers are for write only. Any attempt to read from a
write-only register will result in reading zeroes. Writing to a read-only register will have no
effect on the read even though the write command is acknowledged. The Pointer register
is an 8-bit register. All other registers are 16-bit.
Table 5.
Register summary
Address
POR state
Register name
n/a
n/a
Pointer register
00h
0037h
Capability register (B grade = 0037h)
01h
0000h
Configuration register
02h
0000h
Upper Boundary Alarm Trip register
03h
0000h
Lower Boundary Alarm Trip register
04h
0000h
Critical Alarm Trip register
05h
n/a
Temperature register
06h
1131h
Manufacturer ID register
07h
A102h
Device ID/Revision register
08h to 21h
0000h
reserved registers
22h
0000h
SMBus register
23h to FFh
0000h
reserved registers
A write to reserved registers my cause unexpected results which may result in requiring a
reset by removing and re-applying its power.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
16 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.2 Capability register (00h, 16-bit read-only)
Table 6.
Capability register (address 00h) bit allocation
Bit
15
14
13
12
Symbol
11
10
9
8
RFU[9:2]
Reset
0
0
0
0
0
0
0
0
Access
R
R
R
R
R
R
R
R
Bit
7
6
5
4
3
2
1
0
WRNG
HACC
BCAP
Symbol
RFU[1:0]
VHV
TRES[1:0]
Reset
0
0
1
1
0
1
1
1
Access
R
R
R
R
R
R
R
R
Table 7.
Capability register (address 00h) bit description
Bit
Symbol
Description
15:6
RFU
Reserved for future use. Must be zero.
5
VHV
High voltage standoff for pin A0.
1 — This part can support a voltage up to 10 V on the A0 pin to
support JC42.4 ballot 1435.00.
4:3
TRES
Temperature resolution.
10 — 0.125 °C LSB (11-bit)
2
WRNG
Wider range.
1 — can read temperatures below 0 °C and set sign bit accordingly
1
HACC
Higher accuracy (set during manufacture).
1 — B grade accuracy
0
BCAP
Basic capability.
1 — has Alarm and Critical Trips interrupt capability.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
17 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.3 Configuration register (01h, 16-bit read/write)
Table 8.
Configuration register (address 01h) bit allocation
Bit
15
14
13
Symbol
12
11
10
RFU
9
HEN[1:0]
8
SHMD
Default
0
0
0
0
0
0
0
0
Access
R
R
R
R
R
R/W
R/W
R/W
Bit
7
6
5
4
3
2
1
0
CTLB
AWLB
CEVNT
ESTAT
EOCTL
CVO
EP
EMD
Symbol
Default
0
0
0
0
0
0
0
0
Access
R/W
R/W
R/W
R/W
R/W
R/W
R/W
R/W
Table 9.
Configuration register (address 01h) bit description
Bit
Symbol
Description
15:11
RFU
reserved for future use; must be ‘0’.
10:9
HEN
Hysteresis Enable
00 — Disable hysteresis (default)
01 — Enable hysteresis at 1.5 °C
10 — Enable hysteresis at 3 °C
11 — Enable hysteresis at 6 °C
When enabled, hysteresis is applied to temperature movement around trigger
points. For example, consider the behavior of the ‘Above Alarm Window’ bit
(bit 14 of the Temperature register) when the hysteresis is set to 3 °C. As the
temperature rises, bit 14 will be set to 1 (temperature is above the alarm
window) when the Temperature register contains a value that is greater than
the value in the Alarm Temperature Upper Boundary register. If the
temperature decreases, bit 14 will remain set until the measured temperature
is less than or equal to the value in the Alarm Temperature Upper Boundary
register minus 3 °C. (Refer to Figure 6 and Table 10).
Similarly, the ‘Below Alarm Window’ bit (bit 13 of the Temperature register) will
be set to 0 (temperature is equal to or above the Alarm Window Lower
Boundary Trip register) when the value in the Temperature register is equal to
or greater than the value in the Alarm Temperature Lower Boundary register.
As the temperature decreases, bit 13 will be set to 1 when the value in the
Temperature register is equal to or less than the value in the Alarm
Temperature Lower Boundary register minus 3 °C. Note that hysteresis is also
applied to EVENT pin functionality.
When either of the Critical Trip or Alarm Window lock bits is set, these bits
cannot be altered until unlocked.
8
SHMD
Shutdown Mode.
0 — Enabled Temperature Sensor (default)
1 — Disabled Temperature Sensor
When shut down, the thermal sensor diode and Analog-to-Digital Converter
(ADC) are disabled to save power, no events will be generated. When either of
the Critical Trip or Alarm Window lock bits is set, this bit cannot be set until
unlocked. However, it can be cleared at any time.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
18 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
Table 9.
Configuration register (address 01h) bit description …continued
Bit
Symbol
Description
7
CTLB
Critical Trip Lock bit.
0 — Critical Alarm Trip register is not locked and can be altered (default).
1 — Critical Alarm Trip register settings cannot be altered.
This bit is initially cleared. When set, this bit will return a 1, and remains locked
until cleared by internal Power-on reset. This bit can be written with a single
write and do not require double writes.
6
AWLB
Alarm Window Lock bit.
0 — Upper and Lower Alarm Trip registers are not locked and can be
altered (default).
1 — Upper and Lower Alarm Trip registers setting cannot be altered.
This bit is initially cleared. When set, this bit will return a 1 and remains locked
until cleared by internal power-on reset. This bit can be written with a single
write and does not require double writes.
5
CEVNT
Clear EVENT (write only).
0 — No effect (default).
1 — Clears active EVENT in Interrupt mode. Writing to this register has no
effect in Comparator mode.
When read, this register always returns zero.
4
ESTAT
EVENT Status (read only).
0 — EVENT output condition is not being asserted by this device (default).
1 — EVENT output pin is being asserted by this device due to Alarm
Window or Critical Trip condition.
The actual event causing the EVENT can be determined from the Read
Temperature register. Interrupt Events can be cleared by writing to the
‘Clear EVENT’ bit (CEVNT). Writing to this bit will have no effect.
3
EOCTL
EVENT Output Control.
0 — EVENT output disabled (default).
1 — EVENT output enabled.
When either of the Critical Trip or Alarm Window lock bits is set, this bit cannot
be altered until unlocked.
2
CVO
Critical Event Only.
0 — EVENT output on Alarm or Critical temperature event (default)
1 — EVENT only if temperature is above the value in the critical
temperature register
When the Critical Trip or Alarm Window lock bit is set, this bit cannot be
altered until unlocked.
•
Advisory note:
– JEDEC specification requires only the Alarm Window lock bit to be set.
– Work-around: Clear both Critical Trip and Alarm Window lock bits.
– Future 1.7 V to 3.6 V SE98B will require only the Alarm Window lock
bit to be set.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
19 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
Table 9.
Configuration register (address 01h) bit description …continued
Bit
Symbol
Description
1
EP
EVENT Polarity.
0 — active LOW (default).
1 — active HIGH.
When either of the Critical Trip or Alarm Window lock bits is set, this bit cannot
be altered until unlocked.
0
EMD
EVENT Mode.
0 — comparator output mode (default)
1 — interrupt mode
When either of the Critical Trip or Alarm Window lock bits is set, this bit cannot
be altered until unlocked.
Table 10.
Action
Hysteresis enable
Below Alarm Window bit (bit 13)
Above Alarm Window bit (bit 14)
Above Critical Trip bit (bit 15)
Temperature
slope
Threshold
temperature
Temperature
slope
Threshold
temperature
Temperature
slope
sets
falling
Ttrip(l) − Thys
rising
Ttrip(u)
rising
Tth(crit)
clears
rising
Ttrip(l)
falling
Ttrip(u) − Thys
falling
Tth(crit) − Thys
Threshold
temperature
current temperature
temperature
critical alarm
threshold
hysteresis
upper alarm
threshold
hysteresis
lower alarm
threshold
hysteresis
time
Above Critical Trip
(register 05h;
bit 15 = ACT bit)
clear
set
clear
Above Alarm Window
(register 05h;
bit 14 = AAW bit)
clear
set
clear
Below Alarm Window
(register 05h;
bit 13 = BAW bit)
set
clear
002aac799
Fig 12. Hysteresis: how it works
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
20 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.4 Temperature format
The 16-bit value used in the following Trip Point Set and Temperature Read-Back
registers is 2’s complement with the Least Significant Bit (LSB) equal to 0.0625 °C. For
example:
• A value of 019Ch will represent 25.75 °C
• A value of 07C0h will represent 124 °C
• A value of 1E64h will represent −25.75 °C.
The resolution is 0.125 °C. The unused LSB (bit 0) is set to ‘0’. Bit 11 will have a resolution
of 128 °C.
The upper 3 bits of the temperature register indicate Trip Status based on the current
temperature, and are not affected by the status of the EVENT output.
Table 11 lists the examples of the content of the temperature data register for positive and
negative temperature for two scenarios of status bits: status bits = 000b and
status bits = 111b.
Table 11.
Degree Celsius and Temperature Data register
Temperature
Content of Temperature Data register
Status bits = 000b
Status bits = 111b
Binary
Hex
Binary
Hex
+125 °C
000 0 01111101 000 0
07D0h
111 0 01111101 000 0
E7D0h
+25 °C
000 0 00011001 000 0
0190h
111 0 00011001 000 0
E190h
+1 °C
000 0 00000001 000 0
0010h
111 0 00000001 000 0
E010h
+0.25 °C
000 0 00000000 010 0
0004h
111 0 00000000 010 0
E004h
+0.125 °C
000 0 00000000 001 0
0002h
111 0 00000000 001 0
E002h
0 °C
000 0 00000000 000 0
0000h
111 0 00000000 000 0
E000h
−0.125 °C
000 1 11111111 111 0
1FFEh
111 1 11111111 111 0
FFFEh
−0.25 °C
000 1 11111111 110 0
1FFCh
111 1 11111111 110 0
FFFCh
−1 °C
000 1 11111111 000 0
1FF0h
111 1 11111111 000 0
FFF0h
−20 °C
000 1 11110100 000 0
1F40h
111 1 11110100 000 0
FF40h
−25 °C
000 1 11100111 000 0
1E70h
111 1 11100111 000 0
FE70h
−55 °C
000 1 11001001 000 0
1C90h
111 1 11001001 000 0
FC90h
SE98A_4
Product data sheet
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Rev. 04 — 25 November 2009
21 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.5 Temperature Trip Point registers
8.5.1 Upper Boundary Alarm Trip register (16-bit read/write)
The value is the upper threshold temperature value for Alarm mode. The data format is
2’s complement with bit 2 = 0.25 °C. ‘RFU’ bits will always report zero. Interrupts will
respond to the presently programmed boundary values. If boundary values are being
altered in-system, it is advised to turn off interrupts until a known state can be obtained to
avoid superfluous interrupt activity.
Table 12.
Bit
Upper Boundary Alarm Trip register bit allocation
15
Symbol
14
13
12
RFU
10
SIGN
9
8
UBT[9:6]
Reset
0
0
0
0
0
0
0
0
Access
R
R
R
R/W
R/W
R/W
R/W
R/W
Bit
7
6
5
4
3
2
1
0
Symbol
Reset
Access
UBT[5:0]
RFU
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R
R
Table 13.
Upper Boundary Alarm Trip register bit description
Bit
Symbol
Description
15:13
RFU
reserved; always 0
12
SIGN
Sign (MSB)
11:2
UBT
Upper Boundary Alarm Trip Temperature (LSB = 0.25 °C)
1:0
RFU
reserved; always 0
SE98A_4
Product data sheet
11
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
22 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.5.2 Lower Boundary Alarm Trip register (16-bit read/write)
The value is the lower threshold temperature value for Alarm mode. The data format is
2’s complement with bit 2 = 0.25 °C. RFU bits will always report zero. Interrupts will
respond to the presently programmed boundary values. If boundary values are being
altered in-system, it is advised to turn off interrupts until a known state can be obtained to
avoid superfluous interrupt activity.
Table 14.
Lower Boundary Alarm Trip register bit allocation
Bit
15
Symbol
14
13
12
RFU
11
10
SIGN
9
8
LBT[9:6]
Reset
0
0
0
0
0
0
0
0
Access
R
R
R
R/W
R/W
R/W
R/W
R/W
Bit
7
6
5
4
3
2
1
0
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R
R
Symbol
LBT[5:0]
Reset
Access
RFU
Table 15.
Lower Boundary Alarm Trip register bit description
Bit
Symbol
Description
15:13
RFU
reserved; always 0
12
SIGN
Sign (MSB)
11:2
LBT
Lower Boundary Alarm Trip Temperature (LSB = 0.25 °C)
1:0
RFU
reserved; always 0
8.5.3 Critical Alarm Trip register (16-bit read/write)
The value is the critical temperature. The data format is 2’s complement with
bit 2 = 0.25 °C. RFU bits will always report zero.
Table 16.
Lower Boundary Alarm Trip register bit allocation
Bit
15
Symbol
14
13
12
RFU
10
SIGN
9
8
CT[9:6]
Reset
0
0
0
0
0
0
0
0
Access
R
R
R
R/W
R/W
R/W
R/W
R/W
Bit
7
6
5
4
3
2
1
0
Symbol
CT[5:0]
Reset
Access
RFU
0
0
0
0
0
0
0
0
R/W
R/W
R/W
R/W
R/W
R/W
R
R
Table 17.
Critical Alarm Trip register bit description
Bit
Symbol
Description
15:13
RFU
reserved; always 0
12
SIGN
Sign (MSB)
11:2
CT
Critical Alarm Trip Temperature (LSB = 0.25 °C)
1:0
RFU
reserved; always 0
SE98A_4
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11
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
23 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.6 Temperature register (16-bit read-only)
Table 18.
Bit
Symbol
Temperature register bit allocation
15
14
13
12
ACT
AAW
BAW
SIGN
11
10
9
8
TEMP[10:7]
Reset
0
0
0
0
0
0
0
0
Access
R
R
R
R
R
R
R
R
Bit
7
6
5
4
3
2
1
0
Symbol
TEMP[6:0]
RFU
Reset
0
0
0
0
0
0
0
0
Access
R
R
R
R
R
R
R
R
Table 19.
Temperature register bit description
Bit
Symbol
15
ACT
Description
Above Critical Trip.
Increasing Tamb:
0 — Tamb < Tth(crit)
1 — Tamb ≥ Tth(crit)
Decreasing Tamb:
0 — Tamb < Tth(crit) − Thys
1 — Tamb ≥ Tth(crit) − Thys
14
AAW
Above Alarm Window.
Increasing Tamb:
0 — Tamb ≤ Ttrip(u)
1 — Tamb > Ttrip(u)
Decreasing Tamb:
0 — Tamb ≤ Ttrip(u) − Thys
1 — Tamb > Ttrip(u) − Thys
13
BAW
Below Alarm Window.
Increasing Tamb:
0 — Tamb ≥ Ttrip(l)
1 — Tamb < Ttrip(l)
Decreasing Tamb:
0 — Tamb ≥ Ttrip(l) − Thys
1 — Tamb < Ttrip(l) − Thys
12
SIGN
Sign bit.
0 — positive temperature value
1 — negative temperature value
11:1
TEMP
Temperature Value (2’s complement). (LSB = 0.125 °C)
0
RFU
reserved; always 0
SE98A_4
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Rev. 04 — 25 November 2009
24 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.7 Manufacturer’s ID register (16-bit read-only)
The manufacture’s ID matches that assigned to NXP Semiconductors PCI-SIG (1131h),
and is intended for use to identify the manufacturer of the device.
Table 20.
Bit
Manufacturer’s ID register bit allocation
15
14
13
Symbol
12
11
10
9
8
Manufacturer ID
Reset
0
0
0
1
0
0
0
1
Access
R
R
R
R
R
R
R
R
Bit
7
6
5
4
3
2
1
0
Symbol
(continued)
Reset
0
0
1
1
0
0
0
1
Access
R
R
R
R
R
R
R
R
10
9
8
8.8 Device ID register
The device ID and device revision are A1h and 02h, respectively.
Table 21.
Bit
Device ID register bit allocation
15
14
13
12
Reset
1
0
1
0
0
0
0
1
Access
R
R
R
R
R
R
R
R
Bit
7
6
5
4
3
2
1
0
Reset
0
0
0
0
0
0
1
0
Access
R
R
R
R
R
R
R
R
Symbol
Device ID
Symbol
Device revision
SE98A_4
Product data sheet
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Rev. 04 — 25 November 2009
25 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
8.9 SMBus register
Table 22.
SMBus Time-out register bit allocation
Bit
15
14
13
12
Symbol
11
10
9
8
RFU
Reset
0
0
0
0
0
0
0
0
Access
R
R
R
R
R
R
R
R
Bit
7
6
5
4
3
2
1
0
Symbol
STMOUT
Reset
Access
Table 23.
Bit
RFU
SALRT
0
0
0
0
0
0
0
0
R/W
R
R
R
R
R
R
R/W
SMBus Time-out register bit description
Symbol
Description
15:8
RFU
reserved; always 0
7
STMOUT
SMBus time-out.
0 — SMBus time-out is enabled (default)
1 — disable SMBus time-out
When either of the Critical Trip or Alarm Window lock bits is set, this bit
cannot be altered until unlocked.
6:1
RFU
reserved; always 0
0
SALRT
SMBus ALERT.
0 — SMBus ALERT is enabled (default)
1 — disable SMBus ALERT
When either of the Critical Trip or Alarm Window lock bits is set, this bit
cannot be altered until unlocked.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
26 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
9. Application design-in information
In a typical application, the SE98A behaves as a slave device and interfaces to the master
(or host) via the SCL and SDA lines. The host monitors the EVENT output pin, which is
asserted when the temperature reading exceeds the programmed values in the alarm
registers. The A0, A1 and A2 pins are directly connected to the shared SPD’s A0, A1 and
A2 pins, otherwise they must be pulled HIGH or LOW. The SDA and SCL serial interface
pins are open-drain and require pull-up resistors, and are able to sink a maximum current
of 3 mA with a voltage drop less than 0.4 V. Typical pull-up values for SCL and SDA are
10 kΩ, but the resistor values can be changed in order to meet the rise time requirement if
the capacitance load is too large due to routing, connectors, or multiple components
sharing the same bus.
slave
VDD
SCL
VSS
SCL
SDA
SPD
master
10 kΩ
(3×)
VDD
EVENT
A0
A1
A2
A0
A1
A2
HOST
CONTROLLER
SDA
SE98A
VSS
002aad900
Fig 13. Typical application
mother board
3.3 V
1.1 V
0.1 μF
0.1 μF
VDD
10 kΩ
10 kΩ
SCL
SE98A
A0
A1
A2
0.1 μF
VCC(B) VCC(A)
B2
A2
PCA9509
SDA
B1
A1
EVENT
10 kΩ
10 kΩ
SCL
SDA
HOST
CONTROLLER
EVENT
EN
VSS
002aad759
Fig 14. SE98A interfacing with 1.1 V host controller
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
27 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
9.1 SE98A in memory module application
Figure 15 shows the SE98A being placed in the memory module application with the
SPD. The SE98A is centered in the memory module to provide the function to monitor the
temperature of the DRAM. In the event of overheat, the SE98A triggers the EVENT output
and the memory controller can throttle the memory bus to slow the DRAM, or the CPU can
increase the refresh rate for the DRAM. The memory controller can also read the SE98A
and watch the DRAM thermal behavior.
DIMM
SPD
DRAM
DRAM
DRAM
DRAM
SE98A
SDA
SCL
SMBus
EVENT
MEMORY CONTROLLER
CPU
002aad760
Fig 15. System application
9.2 Layout consideration
The SE98A does not require any additional components other than the host controller to
measure temperature. A 0.1 μF bypass capacitor between the VDD and VSS pins is
located as close as possible to the power and ground pins for noise protection.
9.3 Thermal considerations
In general, self-heating is the result of power consumption and not a concern, especially
with the SE98A, which consumes very low power. In the event the SDA and EVENT pins
are heavily loaded with small pull-up resistor values, self-heating affects temperature
accuracy by approximately 0.5 °C.
Equation 1 is the formula to calculate the effect of self-heating:
ΔT = R th ( j-a ) ×
[ ( V DD × I DD ( AV ) ) + ( V OL ( SDA ) × I OL ( sin k ) ( SDA ) ) + ( V OL ( EVENT ) × I OL ( sin k )EVENT ) ]
(1)
where:
ΔT = Tj − Tamb
Tj = junction temperature
Tamb = ambient temperature
Rth(j-a) = package thermal resistance
VDD = supply voltage
IDD(AV) = average supply current
VOL(SDA) = LOW-level output voltage on pin SDA
VOL(EVENT) = LOW-level output voltage on pin EVENT
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
28 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
IOL(sink)(SDA) = SDA output current LOW
IOL(sink)EVENT = EVENT output current LOW
10. Limiting values
Table 24. Limiting values
In accordance with the Absolute Maximum Rating System (IEC 60134).
Symbol
Parameter
Conditions
Min
Max
Unit
VDD
supply voltage
Vn
voltage on any other pin
SDA, SCL, EVENT pins
−0.3
+4.2
V
−0.3
+4.2
V
VA0
voltage on pin A0
overvoltage input; A0 pin
−0.3
+12.5
V
Isink
sink current
at SDA, SCL, EVENT pins
−1
+50.0
mA
Tj(max)
Tstg
maximum junction temperature
-
150
°C
storage temperature
−65
+165
°C
11. Characteristics
Table 25. Characteristics
VDD = 1.7 V to 3.6 V; Tamb = −40 °C to +125 °C; unless otherwise specified.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
Tacc
temperature accuracy
B grade temperature accuracy;
VDD = 1.7 V to 3.6 V
Tamb = 75 °C to 95 °C
−1.0
< ±0.5
+1.0
°C
Tamb = 40 °C to 125 °C
−2.0
< ±1
+2.0
°C
Tamb = −40 °C to +125 °C
−3.0
< ±2
+3.0
°C
Tres
temperature resolution
-
0.125
-
°C
IDD(AV)
average supply current
-
250
400
μA
IDD(stb)
standby supply current
-
0.1
5
μA
Tconv
conversion period
-
100
120
ms
Ef(conv)
conversion rate error
−30
-
+30
%
ILIL
LOW-level input leakage current pins A0, A1, A2; VI = VSS
−1.0
-
+1.0
μA
Ipd
pull-down current
internal; pins A0, A1, A2;
VI = 0.3VDD to VDD
0.05
-
4.0
μA
ZIL
LOW-level input impedance
pins A0, A1, A2; VI < 0.3VDD
30
-
-
kΩ
ZIH
HIGH-level input impedance
pins A0, A1, A2; VI ≥ 0.3VDD
800
-
-
kΩ
VDD
supply voltage
1.7
1.8 or 2.5
or 3.3
3.6
V
SMBus inactive
percentage error in programmed
data
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
29 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
Table 26. SMBus DC characteristics
VDD = 1.7 V to 3.6 V; Tamb = −20 °C to +120 °C; unless otherwise specified. These specifications are guaranteed by design.
Symbol
Parameter
Conditions
Min
Typ
Max
Unit
VIH
HIGH-level input voltage
SCL, SDA;
VDD = 1.7 V to 3.6 V
0.7VDD
-
VDD + 1
V
VIL
LOW-level input voltage
SCL, SDA;
VDD = 1.7 V to 3.6 V
-
-
0.3VDD
V
VI(ov)
overvoltage input voltage
pin A0;
VI(ov) − VDD > 4.8 V
7.0
-
10
V
Vth(POR)H
HIGH-level power-on reset
threshold voltage
-
-
1.7
V
Vth(rec)POR
power-on reset recovery
threshold voltage
for device reset
-
-
0.5
V
IOL(sink)EVENT
LOW-level output sink current on
pin EVENT
VOL = 0.4 V
6
-
-
mA
IOL(sink)(SDA)
LOW-level output sink current on
pin SDA
VOL = 0.5 V
3
-
-
mA
ILOH
HIGH-level output leakage current
VOH = VDD
-
-
1.0
μA
ILIH
HIGH-level input leakage current
pins SCL, SDA;
VI = VDD or VSS
−1.0
-
+1.0
μA
ILIL
LOW-level input leakage current
pins SCL, SDA;
VI = VDD or VSS
−1.0
-
+1.0
μA
Ci
input capacitance
SCL, SDA pins
-
5
10
pF
[1]
[1]
High-voltage input voltage applied to pin A0 during RWP and CRWP operations of the equivalent SPD-included parts. The JEDEC
specification is 7 V (min.) and 10 V (max.). When VDD is 3.6 V, then VI(ov) > 4.8 V + VDD or > 4.8 V + 3.6 V then the minimum voltage is
8.4 V.
002aae374
350
IDD(AV)
(μA)
250
IDD(AV)
(μA)
VDD = 3.6 V
3.0 V
2.3 V
1.7 V
002aae375
VDD = 3.6 V
3.0 V
2.3 V
1.7 V
250
150
50
−50
350
150
−25
0
25
50
a. I2C-bus inactive
75
125
100
Tamb (°C)
50
−50
−25
0
25
50
75
125
100
Tamb (°C)
b. I2C-bus active
Fig 16. Average supply current
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
30 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
002aad881
5
Tacc
(°C)
Isd(VDD)
(μA)
002aae376
3.0
2.0
1.0
3
VDD = 3.6 V
3.0 V
2.3 V
1.7 V
0
−1.0
1
−2.0
−1
−40
0
40
80
120
Tamb (°C)
−3.0
−50
I2C-bus and temp sensor inactive.
−25
0
25
50
75
100
125
Tamb (°C)
VDD = 1.7 V to 3.6 V.
Fig 17. Shutdown supply current
Fig 18. Typical temperature accuracy
002aae377
30
IOL(sink)EVENT
(mA)
002aae378
30
IOL(sink)SDA
(mA)
20
VDD = 3.6 V
3.0 V
2.3 V
1.7 V
20
10
10
0
−50
VDD = 3.6 V
3.0 V
2.3 V
1.7 V
−25
0
25
50
75
125
100
Tamb (°C)
0
−50
VOL = 0.4 V.
−25
0
25
50
125
100
Tamb (°C)
75
VOL = 0.5 V.
Fig 19. EVENT output current
Fig 20. SDA output current
002aad886
15
conversion rate
(conv/s)
13
002aad887
140
Tconv
(ms)
120
11
100
9
80
7
5
−40
0
VDD = 3.0 V to 3.6 V.
Fig 21. Conversion rate
40
80
120
Tamb (°C)
60
−40
40
80
120
Tamb (°C)
VDD = 3.0 V to 3.6 V.
Fig 22. Conversion period
SE98A_4
Product data sheet
0
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
31 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
002aad889
3.0
Vth
(V)
002aad891
120
thermal
response
(%)
2.5
80
(1)
(2)
2.0
40
1.5
1.0
−40
0
40
80
0
120
Tamb (°C)
0
1
2
3
4
5
time (s)
From 25 °C (air) to 120 °C (oil bath).
For temp sensor conversion.
(1) TSSOP8
(2) HWSON8
Fig 23. Average power-on threshold voltage
Fig 24. Package thermal response
002aad892
5
temp error
(˚C)
3
1
−1
102
103
104
105
106
107
108
noise frequency (Hz)
VDD = 3.3 V + 150 mV (p-p); 0.1 μF AC coupling capacitor; no decoupling capacitor; Tamb = 25 °C.
Fig 25. Temperature error versus power supply noise frequency
002aae379
3.0
Ipd
(μA)
Ipd
(μA)
2.0
2.0
VDD = 3.6 V
3.0 V
2.3 V
1.7 V
VDD = 3.6 V
3.0 V
2.3 V
1.7 V
1.0
0
−50
002aae380
3.0
1.0
−25
0
25
50
75
a. VI = 0.3VDD; pins A0, A1, A2
125
100
Tamb (°C)
0
−50
−25
0
25
50
75
125
100
Tamb (°C)
b. VI = 0.7VDD; pins A0, A1, A2
Fig 26. Typical pull-down current
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
32 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
Table 27. SMBus AC characteristics
VDD = 1.7 V to 3.6 V; Tamb = −40 °C to +125 °C; unless otherwise specified. These specifications are guaranteed by design.
The AC specifications fully meet or exceed SMBus 2.0 specifications, but allow the bus to interface with the I2C-bus from DC
to 400 kHz.
Symbol
Parameter
Conditions
Standard mode
Min
Fast mode
Unit
Max
Min
Max
400
fSCL
SCL clock frequency
10[1]
100
10[1]
tHIGH
HIGH period of the SCL clock 70 % to 70 %
4000
-
600
-
ns
tLOW
LOW period of the SCL clock 30 % to 30 %
4700
-
1300
-
ns
tto(SMBus)
SMBus time-out time
25
35
25
35
ms
tr
rise time of both SDA and
SCL signals
-
1000
20
300
ns
tf
fall time of both SDA and SCL
signals
-
300
-
300
ns
tSU;DAT
data set-up time
250
-
100
-
ns
th(i)(D)
data input hold time
LOW period to reset
SMBus
[2][3]
kHz
0
-
0
-
ns
data hold time
[4]
200
3450
200
900
ns
tSU;STA
set-up time for a repeated
START condition
[5]
4700
-
600
-
ns
tHD;STA
hold time (repeated) START
condition
[6]
4000
-
600
-
ns
tSU;STO
set-up time for STOP
condition
4000
-
600
-
ns
tBUF
bus free time between a
STOP and START condition
4700
-
1300
-
ns
tSP
pulse width of spikes that
must be suppressed by the
input filter
-
50
-
50
ns
tVD;DAT
data valid time
from clock
200
-
200
-
ns
tf(o)
output fall time
-
-
-
250
ns
tPOR
power-on reset pulse time
power supply falling
0.5
-
0.5
-
μs
tHD;DAT
30 % of SDA to
70 % of SCL
[2]
[1]
Minimum clock frequency is 0 kHz if SMBus Time-out is disabled.
[2]
Delay from SDA STOP to SDA START.
[3]
A device must internally provide a hold time of at least 200 ns for SDA signal (referenced to the VIH(min) of the SCL signal) to bridge the
undefined region of the falling edge of SCL.
[4]
Delay from SCL HIGH-to-LOW transition to SDA edges.
[5]
Delay from SCL LOW-to-HIGH transition to restart SDA.
[6]
Delay from SDA START to first SCL HIGH-to-LOW transition.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
33 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
tLOW
tr
tf
VIH
VIL
SCL
tHD;STA
tHD;DAT
tBUF
tHIGH
tSU;STA
tSU;STO
tSU;DAT
tHD;DAT
VIH
VIL
SDA
P
S
S
P
VIH
VIL
SCL
tSU;STA
tSU;STO
VIH
VIL
SDA
tW
STOP
condition
write cycle
START
condition
002aae750
S = START condition
P = STOP condition
Fig 27. AC waveforms
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
34 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
12. Package outline
TSSOP8: plastic thin shrink small outline package; 8 leads; body width 4.4 mm
SOT530-1
E
A
D
X
c
y
HE
v M A
Z
8
5
A2
A
(A3)
A1
pin 1 index
θ
Lp
L
detail X
1
4
e
w M
bp
0
2.5
5 mm
scale
DIMENSIONS (mm are the original dimensions)
UNIT
A
max.
A1
A2
A3
bp
c
D(1)
E(2)
e
HE
L
Lp
v
w
y
Z(1)
θ
mm
1.1
0.15
0.05
0.95
0.85
0.25
0.30
0.19
0.20
0.13
3.1
2.9
4.5
4.3
0.65
6.5
6.3
0.94
0.7
0.5
0.1
0.1
0.1
0.70
0.35
8°
0°
Notes
1. Plastic or metal protrusions of 0.15 mm maximum per side are not included.
2. Plastic or metal protrusions of 0.25 mm maximum per side are not included.
OUTLINE
VERSION
SOT530-1
REFERENCES
IEC
JEDEC
JEITA
MO-153
EUROPEAN
PROJECTION
ISSUE DATE
00-02-24
03-02-18
Fig 28. Package outline SOT530-1 (TSSOP8)
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
35 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
HWSON8: plastic thermal enhanced very very thin small outline package; no leads;
8 terminals; body 2 x 3 x 0.8 mm
SOT1069-2
X
A
B
D
A2
A
E
A1
A3
terminal 1
index area
detail X
e1
terminal 1
index area
e
1
4
C
C A B
C
v
w
b
y
y1 C
L
K
E2
8
5
D2
0
1
scale
Dimensions
Unit
mm
2 mm
A(1)
A1
A2
max 0.80 0.05 0.65
nom 0.75 0.02 0.55
min 0.70 0.00 0.45
A3
b
D(1)
D2
E(1)
E2
0.2
0.30
0.25
0.18
2.1
2.0
1.9
1.6
1.5
1.4
3.1
3.0
2.9
1.6
1.5
1.4
e
0.5
e1
1.5
K
L
0.40 0.45
0.35 0.40
0.30 0.35
v
0.1
w
y
y1
0.05 0.05 0.05
Note
1. Plastic or metal protrusions of 0.075 mm maximum per side are not included.
References
Outline
version
IEC
JEDEC
JEITA
SOT1069-2
---
MO-229
---
sot1069-2_po
European
projection
Issue date
09-10-22
09-11-18
Fig 29. Package outline SOT1069-2 (HWSON8)
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
36 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
HXSON8: plastic thermal enhanced extremely thin small outline package; no leads;
8 terminals; body 2 x 3 x 0.5 mm
X
b
v
A B
M
B
D
SOT1052-1
A
A
E
A1
detail X
terminal 1
index area
C
1/2 e
terminal 1
index area
y1 C
e
1
y
4
L
(8×)
Eh
8
5
Dh
0
1
scale
DIMENSIONS (mm are the original dimensions)
UNIT
mm
max
nom
min
A(1)
A1
b
D
D1
E
E1
0.5
0.04
0.3
2.1
2.0
1.9
1.6
3.1
3.0
2.9
1.6
0.2
1.4
2 mm
e
L
v
y
y1
0.1
0.05
0.05
0.45
0.5
1.4
0.35
Note
1. Dimension A is including plating thickness. The package footprint is compatible with JEDEC MO229
OUTLINE
VERSION
SOT1052-1
REFERENCES
IEC
JEDEC
JEITA
EUROPEAN
PROJECTION
ISSUE DATE
08-01-11
08-03-11
MO-229
Fig 30. Package outline SOT1052-1 (HXSON8)
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
37 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
13. Soldering of SMD packages
This text provides a very brief insight into a complex technology. A more in-depth account
of soldering ICs can be found in Application Note AN10365 “Surface mount reflow
soldering description”.
13.1 Introduction to soldering
Soldering is one of the most common methods through which packages are attached to
Printed Circuit Boards (PCBs), to form electrical circuits. The soldered joint provides both
the mechanical and the electrical connection. There is no single soldering method that is
ideal for all IC packages. Wave soldering is often preferred when through-hole and
Surface Mount Devices (SMDs) are mixed on one printed wiring board; however, it is not
suitable for fine pitch SMDs. Reflow soldering is ideal for the small pitches and high
densities that come with increased miniaturization.
13.2 Wave and reflow soldering
Wave soldering is a joining technology in which the joints are made by solder coming from
a standing wave of liquid solder. The wave soldering process is suitable for the following:
• Through-hole components
• Leaded or leadless SMDs, which are glued to the surface of the printed circuit board
Not all SMDs can be wave soldered. Packages with solder balls, and some leadless
packages which have solder lands underneath the body, cannot be wave soldered. Also,
leaded SMDs with leads having a pitch smaller than ~0.6 mm cannot be wave soldered,
due to an increased probability of bridging.
The reflow soldering process involves applying solder paste to a board, followed by
component placement and exposure to a temperature profile. Leaded packages,
packages with solder balls, and leadless packages are all reflow solderable.
Key characteristics in both wave and reflow soldering are:
•
•
•
•
•
•
Board specifications, including the board finish, solder masks and vias
Package footprints, including solder thieves and orientation
The moisture sensitivity level of the packages
Package placement
Inspection and repair
Lead-free soldering versus SnPb soldering
13.3 Wave soldering
Key characteristics in wave soldering are:
• Process issues, such as application of adhesive and flux, clinching of leads, board
transport, the solder wave parameters, and the time during which components are
exposed to the wave
• Solder bath specifications, including temperature and impurities
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
38 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
13.4 Reflow soldering
Key characteristics in reflow soldering are:
• Lead-free versus SnPb soldering; note that a lead-free reflow process usually leads to
higher minimum peak temperatures (see Figure 31) than a SnPb process, thus
reducing the process window
• Solder paste printing issues including smearing, release, and adjusting the process
window for a mix of large and small components on one board
• Reflow temperature profile; this profile includes preheat, reflow (in which the board is
heated to the peak temperature) and cooling down. It is imperative that the peak
temperature is high enough for the solder to make reliable solder joints (a solder paste
characteristic). In addition, the peak temperature must be low enough that the
packages and/or boards are not damaged. The peak temperature of the package
depends on package thickness and volume and is classified in accordance with
Table 28 and 29
Table 28.
SnPb eutectic process (from J-STD-020C)
Package thickness (mm)
Package reflow temperature (°C)
Volume (mm3)
≥ 350
< 350
< 2.5
235
220
≥ 2.5
220
220
Table 29.
Lead-free process (from J-STD-020C)
Package thickness (mm)
Package reflow temperature (°C)
Volume (mm3)
< 350
350 to 2000
> 2000
< 1.6
260
260
260
1.6 to 2.5
260
250
245
> 2.5
250
245
245
Moisture sensitivity precautions, as indicated on the packing, must be respected at all
times.
Studies have shown that small packages reach higher temperatures during reflow
soldering, see Figure 31.
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
39 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
maximum peak temperature
= MSL limit, damage level
temperature
minimum peak temperature
= minimum soldering temperature
peak
temperature
time
001aac844
MSL: Moisture Sensitivity Level
Fig 31. Temperature profiles for large and small components
For further information on temperature profiles, refer to Application Note AN10365
“Surface mount reflow soldering description”.
14. Abbreviations
Table 30.
Abbreviations
Acronym
Description
ADC
Analog-to-Digital Converter
ARA
Alert Response Address
BIOS
Basic Input/Output System
CDM
Charged-Device Model
CMOS
Complementary Metal-Oxide Semiconductor
CPU
Central Processing Unit
CRWP
Clear Reversible Write Protection
DDR
Double Data Rate
DDR2
Double Data Rate 2
DDR3
Double Data Rate 3
DIMM
Dual In-line Memory Module
DRAM
Dynamic Random Access Memory
ESD
ElectroStatic Discharge
HBM
Human Body Model
I2C-bus
Inter IC bus
I/O
Input/Output
LSB
Least Significant Bit
MM
Machine Model
MSB
Most Significant Bit
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
40 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
Table 30.
Abbreviations …continued
Acronym
Description
RDIMM
Registered Dual In-line Memory Module
SO-DIMM
Small Outline Dual In-line Memory Module
PC
Personal Computer
POR
Power-On Reset
RWP
Reversible Write Protection
SMBus
System Management Bus
SPD
Serial Presence Detect
15. Revision history
Table 31.
Revision history
Document ID
Release date
Data sheet status
Change notice
Supersedes
SE98A_4
20091125
Product data sheet
-
SE98A_3
Modifications:
SE98A_3
•
Table 1 “Ordering information”: for Type number SE98ATP, the Version is changed from
“SOT1069-1” to “SOT1069-2”
•
Figure 29: package outline drawing changed from “SOT1069-1” to “SOT1069-2”
20090817
Product data sheet
-
SE98A_2
SE98A_2
20090806
Product data sheet
-
SE98A_1
SE98A_1
20090305
Product data sheet
-
-
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
41 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
16. Legal information
16.1 Data sheet status
Document status[1][2]
Product status[3]
Objective [short] data sheet
Development
This document contains data from the objective specification for product development.
Preliminary [short] data sheet
Qualification
This document contains data from the preliminary specification.
Product [short] data sheet
Production
This document contains the product specification.
Definition
[1]
Please consult the most recently issued document before initiating or completing a design.
[2]
The term ‘short data sheet’ is explained in section “Definitions”.
[3]
The product status of device(s) described in this document may have changed since this document was published and may differ in case of multiple devices. The latest product status
information is available on the Internet at URL http://www.nxp.com.
16.2 Definitions
Draft — The document is a draft version only. The content is still under
internal review and subject to formal approval, which may result in
modifications or additions. NXP Semiconductors does not give any
representations or warranties as to the accuracy or completeness of
information included herein and shall have no liability for the consequences of
use of such information.
Short data sheet — A short data sheet is an extract from a full data sheet
with the same product type number(s) and title. A short data sheet is intended
for quick reference only and should not be relied upon to contain detailed and
full information. For detailed and full information see the relevant full data
sheet, which is available on request via the local NXP Semiconductors sales
office. In case of any inconsistency or conflict with the short data sheet, the
full data sheet shall prevail.
16.3 Disclaimers
General — Information in this document is believed to be accurate and
reliable. However, NXP Semiconductors does not give any representations or
warranties, expressed or implied, as to the accuracy or completeness of such
information and shall have no liability for the consequences of use of such
information.
Right to make changes — NXP Semiconductors reserves the right to make
changes to information published in this document, including without
limitation specifications and product descriptions, at any time and without
notice. This document supersedes and replaces all information supplied prior
to the publication hereof.
Suitability for use — NXP Semiconductors products are not designed,
authorized or warranted to be suitable for use in medical, military, aircraft,
space or life support equipment, nor in applications where failure or
malfunction of an NXP Semiconductors product can reasonably be expected
to result in personal injury, death or severe property or environmental
damage. NXP Semiconductors accepts no liability for inclusion and/or use of
NXP Semiconductors products in such equipment or applications and
therefore such inclusion and/or use is at the customer’s own risk.
Applications — Applications that are described herein for any of these
products are for illustrative purposes only. NXP Semiconductors makes no
representation or warranty that such applications will be suitable for the
specified use without further testing or modification.
Limiting values — Stress above one or more limiting values (as defined in
the Absolute Maximum Ratings System of IEC 60134) may cause permanent
damage to the device. Limiting values are stress ratings only and operation of
the device at these or any other conditions above those given in the
Characteristics sections of this document is not implied. Exposure to limiting
values for extended periods may affect device reliability.
Terms and conditions of sale — NXP Semiconductors products are sold
subject to the general terms and conditions of commercial sale, as published
at http://www.nxp.com/profile/terms, including those pertaining to warranty,
intellectual property rights infringement and limitation of liability, unless
explicitly otherwise agreed to in writing by NXP Semiconductors. In case of
any inconsistency or conflict between information in this document and such
terms and conditions, the latter will prevail.
No offer to sell or license — Nothing in this document may be interpreted or
construed as an offer to sell products that is open for acceptance or the grant,
conveyance or implication of any license under any copyrights, patents or
other industrial or intellectual property rights.
Export control — This document as well as the item(s) described herein
may be subject to export control regulations. Export might require a prior
authorization from national authorities.
16.4 Trademarks
Notice: All referenced brands, product names, service names and trademarks
are the property of their respective owners.
I2C-bus — logo is a trademark of NXP B.V.
17. Contact information
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
SE98A_4
Product data sheet
© NXP B.V. 2009. All rights reserved.
Rev. 04 — 25 November 2009
42 of 43
SE98A
NXP Semiconductors
DDR memory module temp sensor, 1.7 V to 3.6 V
18. Contents
1
2
3
4
5
6
6.1
6.2
7
7.1
7.2
7.3
7.3.1
7.3.2
7.3.2.1
7.3.2.2
7.3.3
7.3.3.1
7.3.3.2
7.4
7.4.1
7.5
7.6
7.7
7.8
7.9
7.10
8
8.1
8.2
8.3
8.4
8.5
8.5.1
8.5.2
8.5.3
8.6
8.7
General description . . . . . . . . . . . . . . . . . . . . . . 1
Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
Applications . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
Ordering information . . . . . . . . . . . . . . . . . . . . . 2
Block diagram . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Pinning information . . . . . . . . . . . . . . . . . . . . . . 4
Pinning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Pin description . . . . . . . . . . . . . . . . . . . . . . . . . 4
Functional description . . . . . . . . . . . . . . . . . . . 5
Serial bus interface . . . . . . . . . . . . . . . . . . . . . . 5
Slave address . . . . . . . . . . . . . . . . . . . . . . . . . . 5
EVENT output condition . . . . . . . . . . . . . . . . . . 6
EVENT pin output voltage levels and resistor
sizing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
EVENT thresholds . . . . . . . . . . . . . . . . . . . . . . 8
Alarm window . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Critical trip. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
Event operation modes. . . . . . . . . . . . . . . . . . . 9
Comparator mode. . . . . . . . . . . . . . . . . . . . . . . 9
Interrupt mode . . . . . . . . . . . . . . . . . . . . . . . . . 9
Conversion rate . . . . . . . . . . . . . . . . . . . . . . . 10
What temperature is read when conversion
is in progress . . . . . . . . . . . . . . . . . . . . . . . . . 10
Power-up default condition . . . . . . . . . . . . . . . 11
Device initialization . . . . . . . . . . . . . . . . . . . . . 11
SMBus Time-out . . . . . . . . . . . . . . . . . . . . . . . 12
SMBus ALERT . . . . . . . . . . . . . . . . . . . . . . . . 12
SMBus/I2C-bus interface . . . . . . . . . . . . . . . . 13
Hot plugging . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Register descriptions . . . . . . . . . . . . . . . . . . . 16
Register overview . . . . . . . . . . . . . . . . . . . . . . 16
Capability register
(00h, 16-bit read-only) . . . . . . . . . . . . . . . . . . 17
Configuration register
(01h, 16-bit read/write) . . . . . . . . . . . . . . . . . . 18
Temperature format . . . . . . . . . . . . . . . . . . . . 21
Temperature Trip Point registers . . . . . . . . . . 22
Upper Boundary Alarm Trip register
(16-bit read/write) . . . . . . . . . . . . . . . . . . . . . . 22
Lower Boundary Alarm Trip register
(16-bit read/write) . . . . . . . . . . . . . . . . . . . . . . 23
Critical Alarm Trip register
(16-bit read/write) . . . . . . . . . . . . . . . . . . . . . . 23
Temperature register (16-bit read-only) . . . . . 24
Manufacturer’s ID register
(16-bit read-only) . . . . . . . . . . . . . . . . . . . . . . 25
8.8
8.9
9
9.1
9.2
9.3
10
11
12
13
13.1
13.2
13.3
13.4
14
15
16
16.1
16.2
16.3
16.4
17
18
Device ID register . . . . . . . . . . . . . . . . . . . . .
SMBus register . . . . . . . . . . . . . . . . . . . . . . .
Application design-in information . . . . . . . . .
SE98A in memory module application . . . . . .
Layout consideration . . . . . . . . . . . . . . . . . . .
Thermal considerations . . . . . . . . . . . . . . . . .
Limiting values . . . . . . . . . . . . . . . . . . . . . . . .
Characteristics . . . . . . . . . . . . . . . . . . . . . . . .
Package outline. . . . . . . . . . . . . . . . . . . . . . . .
Soldering of SMD packages . . . . . . . . . . . . . .
Introduction to soldering. . . . . . . . . . . . . . . . .
Wave and reflow soldering. . . . . . . . . . . . . . .
Wave soldering . . . . . . . . . . . . . . . . . . . . . . .
Reflow soldering . . . . . . . . . . . . . . . . . . . . . .
Abbreviations . . . . . . . . . . . . . . . . . . . . . . . . .
Revision history . . . . . . . . . . . . . . . . . . . . . . .
Legal information . . . . . . . . . . . . . . . . . . . . . .
Data sheet status . . . . . . . . . . . . . . . . . . . . . .
Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . .
Disclaimers . . . . . . . . . . . . . . . . . . . . . . . . . .
Trademarks . . . . . . . . . . . . . . . . . . . . . . . . . .
Contact information . . . . . . . . . . . . . . . . . . . .
Contents. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
25
26
27
28
28
28
29
29
35
38
38
38
38
39
40
41
42
42
42
42
42
42
43
Please be aware that important notices concerning this document and the product(s)
described herein, have been included in section ‘Legal information’.
© NXP B.V. 2009.
All rights reserved.
For more information, please visit: http://www.nxp.com
For sales office addresses, please send an email to: salesaddresses@nxp.com
Date of release: 25 November 2009
Document identifier: SE98A_4
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