DATASHEET
X95820
FN8212
Rev 2.00
July 18, 2006
Dual Digital Controlled Potentiometers (XDCP™) Low Noise/Low Power/I2C
Bus/256 Taps
The X95820 integrates two digitally controlled
potentiometers (XDCP) on a monolithic CMOS integrated
circuit.
The digitally controlled potentiometers are implemented with
a combination of resistor elements and CMOS switches. The
position of the wipers are controlled by the user through the
I2C bus interface. Each potentiometer has an associated
volatile Wiper Register (WR) and a non-volatile Initial Value
Register (IVR), that can be directly written to and read by the
user. The contents of the WR controls the position of the
wiper. At power up the device recalls the contents of the two
DCP’s IVR to the corresponding WRs.
Features
• Two potentiometers in one package
• 256 resistor taps-0.4% resolution
• I2C serial interface
- Three address pins, up to eight devices/bus
• Wiper resistance: 70 typical @ 3.3V
• Non-volatile storage of wiper position
• Standby current < 5µA max
• Power supply: 2.7V to 5.5V
The DCPs can be used as three-terminal potentiometers or
as two-terminal variable resistors in a wide variety of
applications including control, parameter adjustments, and
signal processing.
• 50k, 10k total resistance
Ordering Information
• 14 Ld TSSOP
PART NUMBER
PART
MARKING
X95820WV14I-2.7*
X95820WV G
• High reliability
- Endurance: 150,000 data changes per bit per register
- Register data retention: 50 years @ T 75°C
• Pb-free plus anneal available (RoHS compliant)
RESISTANCE
OPTION
PACKAGE
10k
14 Ld TSSOP
X95820WV14IZ-2.7* X95820WV Z G
(Note)
10k
14 Ld TSSOP
(Pb-free)
X95820UV14I-2.7*
50k
14 Ld TSSOP
VCC
1
14
50k
14 Ld TSSOP
(Pb-free)
WP
2
13
A0
RH0
3
12
RH1
4
11
RL1
10
RW1
X95820UV G
X95820UV14IZ-2.7* X95820UV Z G
(Note)
Pinouts
X95820
(14 LD TSSOP)
TOP VIEW
A1
*Add "T1" suffix for tape and reel.
RL0
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
compatible with both SnPb and Pb-free soldering operations. Intersil
Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of
IPC/JEDEC J STD-020.
RW0
5
A2
6
9
GND
SCL
7
8
SDA
FN8212 Rev 2.00
July 18, 2006
Page 1 of 12
X95820
Block Diagram
VCC
I2C
INTERFACE
SDA
SCL
RH1
POWER-UP,
INTERFACE,
CONTROL AND
STATUS LOGIC
WR1
RW1
RL1
A2
RH0
A1
A0
WR0
NON-VOLATILE
REGISTERS
WP
RW0
RL0
GND
PiN Descriptions
PIN
SYMBOL
1
VCC
Power supply pin
2
WP
Hardware write protection pin. Active low. Prevents any “Write” operation of the I2C interface.
3
RH0
“High” terminal of DCP0
4
RL0
“Low” terminal of DCP0
5
RW0
“Wiper” terminal of DCP0
6
A2
7
SCL
I2C interface clock
8
SDA
Serial data I/O for the I2C interface
9
GND
Ground
10
RW1
“Wiper” terminal of DCP1
11
RL1
“Low” terminal of DCP1
12
RH1
“High” terminal of DCP1
13
A0
Device address for the I2C interface
14
A1
Device address for the I2C interface
FN8212 Rev 2.00
July 18, 2006
DESCRIPTION
Device address for the I2C interface
Page 2 of 12
X95820
Absolute Maximum Ratings
Recommended Operating Conditions
Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . .-65C to +150C
Voltage at Any Digital Interface Pin
with Respect to GND . . . . . . . . . . . . . . . . . . . . . . . -0.3V to VCC+0.3
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V
Voltage at Any DCP Pin with Respect to GND . . . . . . -0.3V to VCC
Lead Temperature (soldering, 10s) . . . . . . . . . . . . . . . . . . . . . 300C
IW (10s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±6mA
Temperature Range (Industrial) . . . . . . . . . . . . . . . . . . -40°C to 85°C
VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7V to 5.5V
Power Rating of Each DCP . . . . . . . . . . . . . . . . . . . . . . . . . . . .5mW
Wiper Current of Each DCP. . . . . . . . . . . . . . . . . . . . . . . . . . ±3.0mA
CAUTION: Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only; functional
operation of the device (at these or any other conditions above those listed in the operational sections of this specification) is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect device reliability.
Analog Specifications
SYMBOL
RTOTAL
Over recommended operating conditions unless otherwise stated.
PARAMETER
RH to RL Resistance
TEST CONDITIONS
W, U versions respectively
RH to RL Resistance Tolerance
RW
CH/CL/CW
ILkgDCP
Wiper Resistance
MIN
MAX
10, 50
-20
VCC = 3.3V @ 25°C
Wiper current = VCC/RTOTAL
70
Potentiometer Capacitance (Note 15)
Leakage on DCP Pins (Note 15)
TYP
(Note 1)
k
+20
%
200
10/10/25
Voltage at pin from GND to VCC
0.1
UNIT
pF
1
µA
-1
1
LSB
(Note 2)
-0.5
0.5
LSB
(Note 2)
LSB
(Note 2)
VOLTAGE DIVIDER MODE (0V @ RLi; VCC @ RHi; measured at RWi, unloaded; i = 0 or 1)
INL (Note 6)
Integral Non-linearity
DNL (Note 5) Differential Non-linearity
ZSerror
(Note 3)
Zero-scale Error
FSerror
(Note 4)
Full-scale Error
VMATCH
(Note 7)
DCP to DCP Matching
TCV (Note 8) Ratiometric Temperature Coefficient
Monotonic over all tap positions
U option
0
1
7
W option
0
0.5
2
U option
-7
-1
0
W option
-2
-1
0
Any two DCPs at same tap position, same
voltage at all RH terminals, and same
voltage at all RL terminals
-2
DCP Register set to 80 hex
2
±4
LSB
(Note 2)
LSB
(Note 2)
ppm/°C
RESISTOR MODE (Measurements between RWi and RLi with RHi not connected, or between RWi and RHi with RLi not
connected. i = 0 or 1)
RINL
(Note 12)
Integral Non-linearity
RDNL
(Note 11)
Differential Non-linearity
Roffset
(Note 10)
Offset
DCP register set between 20 hex and
FF hex. Monotonic over all tap positions
1
MI
(Note 9)
-0.5
0.5
MI
(Note 9)
DCP Register set to 00 hex, U option
0
1
7
MI
(Note 9)
DCP Register set to 00 hex, W option
0
0.5
2
MI
(Note 9)
-2
2
MI
(Note 9)
RMATCH
(Note 13)
DCP to DCP Matching
Any two DCPs at the same tap position with
the same terminal voltages.
TCR
(Note 14)
Resistance Temperature Coefficient
DCP register set between 20 hex and FF
hex
FN8212 Rev 2.00
July 18, 2006
-1
±45
ppm/°C
Page 3 of 12
X95820
Operating Specifications Over the recommended operating conditions unless otherwise specified.
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
TYP
(Note 1)
MAX
UNITS
1
mA
ICC1
VCC Supply Current
(Volatile write/read)
fSCL = 400kHz;SDA = Open; (for I2C,
ICC2
VCC Supply Current
(nonvolatile write)
fSCL = 400kHz; SDA = Open; (for I2C,
Active, Nonvolatile Write State only)
3
mA
VCC Current (standby)
VCC = +5.5V, I2C Interface in Standby State
5
µA
= +3.6V, I2C Interface in Standby State
2
µA
10
µA
1
µs
2.6
V
ISB
Active, Read and Volatile Write States only)
VCC
ILkgDig
tDCP
(Note 15)
Vpor
Leakage Current, at Pins A0, Voltage at pin from GND to VCC
A1, A2, SDA, SCL, and WP
Pins
DCP Wiper Response Time
SCL falling edge of last bit of DCP Data Byte to
wiper change
Power-on Recall Voltage
Minimum VCC at which memory recall occurs
VccRamp
VCC Ramp Rate
tD (Note 15)
Power-up Delay
-10
1.8
0.2
VCC above Vpor, to DCP Initial Value Register recall
completed, and I2C Interface in standby state
V/ms
3
ms
EEPROM SPECS
EEPROM Endurance
EEPROM Retention
Temperature 75°C
150,000
Cycles
50
Years
SERIAL INTERFACE SPECS
VIL
WP, A2, A1, A0, SDA, and
SCL input buffer LOW
voltage
-0.3
0.3*Vcc
V
VIH
WP, A2, A1, A0, SDA, and
SCL Input Buffer HIGH
Voltage
0.7*Vcc
Vcc+0.3
V
Hysterisis
(Note 15)
SDA and SCL input buffer
hysterisis
0.05*
Vcc
VOL
(Note 15)
SDA Output Buffer LOW
Voltage, Sinking 4mA
Cpin
(Note 15)
0.4
V
WP, A2, A1, A0, SDA, and
SCL Pin Capacitance
10
pF
SCL Frequency
400
kHz
tIN
(Note 15)
Pulse Width Suppression
Any pulse narrower than the max spec is
Time at SDA and SCL Inputs suppressed.
50
ns
tAA
(Note 15)
SCL Falling Edge to SDA
Output Data Valid
SCL falling edge crossing 30% of VCC, until SDA
exits the 30% to 70% of VCC window.
900
ns
tBUF
(Note 15)
Time the Bus Must be Free
Before the Start of a New
Transmission
SDA crossing 70% of VCC during a STOP condition,
to SDA crossing 70% of VCC during the following
START condition.
1300
ns
tLOW
Clock LOW Time
Measured at the 30% of VCC crossing.
1300
ns
tHIGH
Clock HIGH Time
Measured at the 70% of VCC crossing.
600
ns
tSU:STA
START Condition Setup
Time
SCL rising edge to SDA falling edge. Both crossing
70% of VCC.
600
ns
tHD:STA
START Condition Hold Time
From SDA falling edge crossing 30% of VCC to SCL
falling edge crossing 70% of VCC.
600
ns
fSCL
FN8212 Rev 2.00
July 18, 2006
0
V
Page 4 of 12
X95820
Operating Specifications Over the recommended operating conditions unless otherwise specified. (Continued)
SYMBOL
PARAMETER
TEST CONDITIONS
MIN
tSU:DAT
Input Data Setup Time
From SDA exiting the 30% to 70% of VCC
window, to SCL rising edge crossing 30% of VCC
tHD:DAT
Input Data Hold Time
From SCL rising edge crossing 70% of VCC to SDA
entering the 30% to 70% of VCC window.
tSU:STO
tHD:STO
TYP
(Note 1)
MAX
UNITS
100
ns
0
ns
STOP Condition Setup Time From SCL rising edge crossing 70% of VCC, to SDA
rising edge crossing 30% of VCC.
600
ns
STOP Condition Setup Time From SDA rising edge to SCL falling edge. Both
crossing 70% of VCC.
600
ns
0
ns
tDH (Note 15) Output Data Hold Time
From SCL falling edge crossing 30% of VCC, until
SDA enters the 30% to 70% of VCC window.
tR (Note 15)
SDA and SCL Rise Time
From 30% to 70% of VCC
20 +
0.1 * Cb
250
ns
tF (Note 15)
SDA and SCL Fall Time
From 70% to 30% of VCC
20 +
0.1 * Cb
250
ns
Cb (Note 15)
Capacitive Loading of SDA
or SCL
Total on-chip and off-chip
10
400
pF
Maximum is determined by tR and tF.
For Cb = 400pF, max is about 2~2.5k.
For Cb = 40pF, max is about 15~20k
1
Rpu (Note 15) SDA and SCL Bus Pull-up
resIstor Off-chip
tWP
Non-volatile Write Cycle
(Notes 15, 16) Time
k
12
20
ms
tSU:WPA
A2, A1, A0, and WP Setup
Time
Before START condition
600
ns
tHD:WPA
A2, A1, A0, and WP Hold
Time
After STOP condition
600
ns
SDA vs. SCL Timing
tHIGH
tF
SCL
tLOW
tR
tSU:DAT
tSU:STA
SDA
(INPUT TIMING)
tHD:DAT
tHD:STA
tSU:STO
tAA
tDH
tBUF
SDA
(OUTPUT TIMING)
WP, A0, A1, and A2 Pin Timing
STOP
START
SCL
Clk 1
SDA IN
tSU:WPA
tHD:WPA
WP, A0, A1, or A2
FN8212 Rev 2.00
July 18, 2006
Page 5 of 12
X95820
NOTES:
1. Typical values are for TA = 25°C and 3.3V supply voltage.
2. LSB: [V(RW)255 - V(RW)0] / 255. V(RW)255 and V(RW)0 are V(RW) for the DCP register set to FF hex and 00 hex respectively. LSB is the
incremental voltage when changing from one tap to an adjacent tap.
3. ZS error = V(RW)0 / LSB.
4. FS error = [V(RW)255 - VCC] / LSB.
5. DNL = [V(RW)i - V(RW)i-1] / LSB-1, for i = 1 to 255. i is the DCP register setting.
6. INL = [V(RW)i – (i • LSB – V(RW)0)]/LSB for i = 1 to 255.
7. VMATCH = [V(RWx)i - V(RWy)i] / LSB, for i = 0 to 255, x = 0 to 1 and y = 0 to 1.
Max V RW i – Min V RW i
10 6
8. TC V = ---------------------------------------------------------------------------------------------- ---------------- Max V RW i + Min V RW i 2 125°C
for i = 16 to 240 decimal, T = -40°C to 85°C. Max( ) is the maximum value of the wiper voltage and Min ( ) is the minimum value of the wiper
voltage over the temperature range.
9. MI = |R255 - R0| / 255. R255 and R0 are the measured resistances for the DCP register set to FF hex and 00 hex respectively.
10. Roffset = R0 / MI, when measuring between RW and RL.
Roffset = R255 / MI, when measuring between RW and RH.
11. RDNL = (Ri - Ri-1) / MI, for i = 32 to 255.
12. RINL = [Ri - (MI • i) - R0] / MI, for i = 32 to 255.
13. RMATCH = (Ri,x - Ri,y) / MI, for i = 0 to 255, x = 0 to 1 and y = 0 to 1.
6
Max Ri – Min Ri
10
TC R = ---------------------------------------------------------------- ---------------- Max Ri + Min Ri 2 125°C
for i = 32 to 255, T = -40°C to 85°C. Max( ) is the maximum value of the resistance and Min ( ) is the minimum value of the resistance over the
temperature range.
14.
15. This parameter is not 100% tested.
16. tWC is the minimum cycle time to be allowed for any non-volatile Write by the user, unless Acknowledge Polling is used. It is the time from a
valid STOP condition at the end of a Write sequence of a I2C serial interface Write operation, to the end of the self-timed internal non-volatile
write cycle.
Typical Performance Curves
1.8
160
VCC = 2.7, T = 85°C
VCC = 2.7, T = -40°C
1.6
VCC = 2.7, T = 25°C
1.4
120
STANDBY ICC (µA)
WIPER RESISTANCE ()
140
100
80
60
40
VCC = 5.5, T = 85°C
20
0
VCC = 5.5, T = -40°C
0
50
100
VCC = 5.5, T = 25°C
150
200
TAP POSITION (DECIMAL)
FIGURE 1. WIPER RESISTANCE vs TAP POSITION
[ I(RW) = VCC/RTOTAL ] FOR 50k (U)
FN8212 Rev 2.00
July 18, 2006
250
1.2
1.0
-40°C
0.8
85°C
0.6
0.4
0.2
0.0
2.7
25°C
3.2
3.7
4.2
4.7
5.2
VCC (V)
FIGURE 2. STANDBY ICC vs VCC
Page 6 of 12
X95820
Typical Performance Curves
0.3
0.2
0.15
(Continued)
VCC = 5.5, T = -40°C
VCC = 2.7, T = -40°C
VCC = 5.5, T = -40°C
VCC = 2.7, T = -40°C
VCC = 2.7, T = 25°C
0.2
VCC = 5.5, T = 85°C
0.1
0.1
INL (LSB)
DNL (LSB)
0.05
0
-0.05
-0.1
-0.15
-0.2
0
0
VCC = 2.7, T = 25°C
VCC = 2.7, T = 85°C
-0.1
VCC = 5.5, T = 25°C
VCC = 5.5, T = 25°C
-0.2
VCC = 5.5, T = 85°C
VCC = 2.7, T = 85°C
-0.3
50
100
150
200
250
0
50
100
150
200
250
TAP POSITION (DECIMAL)
TAP POSITION (DECIMAL)
FIGURE 3. DNL vs TAP POSITION IN VOLTAGE DIVIDER
MODE FOR 10k (W)
FIGURE 4. INL vs TAP POSITION IN VOLTAGE DIVIDER
MODE FOR 10k (W)
0
0.4
-0.1
-0.2
0.35
VCC = 5.5V
FSerror (LSB)
ZSerror (LSB)
-0.3
0.3
2.7V
0.25
0.2
-0.4
VCC = 2.7V
-0.5
-0.6
-0.7
-0.8
5.5V
-0.9
0.15
-40
-20
0
20
40
60
-1
-40
80
0.3
40
60
80
0.5
VCC = 2.7, T = 25°C
0.4
VCC = 2.7, T = 25°C
0.3
VCC = 5.5, T = 25°C
VCC = 5.5, T = -40°C
0.2
INL (LSB)
0.1
DNL (LSB)
20
FIGURE 6. FSerror vs TEMPERATURE
FIGURE 5. ZSerror vs TEMPERATURE
0
-0.1
0.1
0
VCC = 5.5, T = 85°C
-0.1
-0.2
VCC = 5.5, T = 85°C
VCC = 2.7, T = 85°C
VCC = 2.7, T = -40°C
VCC = 5.5, T = -40°C
-0.2
-0.3
32
0
TEMPERATURE (°C)
TEMPERATURE (°C)
0.2
-20
82
132
182
TAP POSITION (DECIMAL)
232
FIGURE 7. DNL vs TAP POSITION IN Rheostat MODE FOR
50k (U)
FN8212 Rev 2.00
July 18, 2006
-0.3
-0.4 VCC = 2.7, T = 85°C
VCC = 5.5, T = 25°C
-0.5
32
82
132
VCC = 2.7, T = -40°C
182
232
TAP POSITION (DECIMAL)
FIGURE 8. INL vs TAP POSITION IN Rheostat MODE FOR
50k (U)
Page 7 of 12
X95820
Typical Performance Curves
(Continued)
20
1.00
10
0.50
0.00
2.7V
TC (ppm/°C)
END TO END RTOTAL CHANGE (%)
1.50
5.5V
-0.50
0
-10
-1.00
-1.50
-40
-20
0
20
40
60
80
TEMPERATURE (°C)
-20
32
82
132
182
232
TAP POSITION (DECIMAL)
FIGURE 10. TC FOR VOLTAGE DIVIDER MODE IN ppm
FIGURE 9. END TO END RTOTAL % CHANGE vs
TEMPERATURE
35
INPUT
25
TC (ppm/°C)
15
5
OUTPUT
-5
Tap Position = Mid Point
RTOTAL = 9.4K
-15
-25
32
57
82
107
132
157
182
207
232
TAP POSITION (DECIMAL)
FIGURE 12. FREQUENCY RESPONSE (2.2MHz)
FIGURE 11. TC FOR Rheostat MODE IN ppm
Signal at Wiper (Wiper Unloaded)
SCL
Signal at Wiper
(Wiper Unloaded Movement
From ffh to 00h)
Wiper Movement Mid Point
From 80h to 7fh
FIGURE 13. MIDSCALE GLITCH, CODE 80h TO 7Fh (WIPER 0)
FN8212 Rev 2.00
July 18, 2006
FIGURE 14. LARGE SIGNAL SETTLING TIME
Page 8 of 12
X95820
Principles of Operation
The X95820 in as integrated circuit incorporating two DCPs
with their associated registers, non-volatile memory, and a I2C
serial interface providing direct communication between a host
and the potentiometers and memory.
DCP Description
Each DCP is implemented with a combination of resistor
elements and CMOS switches. The physical ends of each DCP
are equivalent to the fixed terminals of a mechanical
potentiometer (RH and RL pins). The RW pin of each DCP is
connected to intermediate nodes, and is equivalent to the
wiper terminal of a mechanical potentiometer. The position of
the wiper terminal within the DCP is controlled by an 8-bit
volatile Wiper Register (WR). Each DCP has its own WR.
When the WR of a DCP contains all zeroes (WR: 00h),
its wiper terminal (RW) is closest to its “Low” terminal (RL).
When the WR of a DCP contains all ones (WR: FFh), its
wiper terminal (RW) is closest to its “High” terminal (RH). As
the value of the WR increases from all zeroes (00h) to all ones
(255 decimal), the wiper moves monotonically from the
position closest to RL to the closest to RH. At the same time,
the resistance between RW and RL increases monotonically,
while the resistance between RH and RW decreases
monotonically.
While the X95820 is being powered up, all two WRs are reset
to 80h (128 decimal), which locates RW roughly at the center
between RL and RH. Soon after the power supply voltage
becomes large enough for reliable non-volatile memory
reading, the X95820 reads the value stored on two different
non-volatile Initial Value Registers (IVRs) and loads them into
their corresponding WRs.
The WRs and IVRs can be read or written directly using the
I2C serial interface as described in the following sections.
Memory Description
When the byte at address 8 is all zeroes, which is the default at
power up:
• A read operation to addresses 0 or 1 outputs the value of the
non-volatile IVRs.
• A write operation to addresses 0 or 1 writes the same value
to the WR and IVR of the corresponding DCP.
When the byte at address 8 is 80h (128 decimal):
• A read operation to addresses 0 or 1 outputs the value of the
volatile WR.
• A write operation to addresses 0 or 1only writes to the
corresponding volatile WR.
It is not possible to write to an IVR without writing the same
value to its corresponding WR.
00h and 80h are the only values that should be written to
address 8. All other values are reserved and must not be
written to address 8.
To access the general purpose bytes at addresses 2, 3, 4, 5, or
6, the value at address 8 must be all zeros.
The X95820 is pre-programmed with 80h in the two IVRs.
TABLE 1. MEMORY MAP
ADDRESS
NON-VOLATILE
VOLATILE
8
-
Access Control
7
Reserved
6
5
4
3
2
General Purpose
Not Available
1
0
IVR1
IVR0
WR1
WR0
WR: Wiper Register, IVR: Initial value Register.
I2C Serial Interface
The X95820 contains eight non-volatile bytes. they are
accessed by I2C interface operations with Address Bytes 0
through 7 decimal. The first two non-volatile bytes at
addresses 0 and 1 contain the initial value loaded at power-up
into the volatile Wiper Registers (WRs) of DCP0 and DCP1
respectively. Bytes at addresses 2, 3, 4, 5, and 6 are available
to the user as general purpose registers. The byte at address 7
is reserved; the user should not write to it, and its value should
be ignored if read.
The X95820 supports a bidirectional I2C bus oriented protocol.
The protocol defines any device that sends data onto the bus
as a transmitter and the receiving device as the receiver. The
device controlling the transfer is a master and the device being
controlled is the slave. The master always initiates data
transfers and provides the clock for both transmit and receive
operations. Therefore, the X95820 operates as a slave device
in all applications.
The volatile WR, and the non-volatile Initial Value Register
(IVR) of a DCP are accessed with the same Address Byte.
All communication over the I2C interface is conducted by
sending the MSB of each byte of data first.
A volatile byte at address 8 decimal, controls what byte is read
or written when accessing DCP registers: the WR, the IVR, or
both.
Protocol Conventions
FN8212 Rev 2.00
July 18, 2006
Data states on the SDA line can change only during SCL LOW
periods. SDA state changes during SCL HIGH are reserved for
indicating START and STOP conditions (See Figure 15). On
power up of the X95820 the SDA pin is in the input mode.
Page 9 of 12
X95820
All I2C interface operations must begin with a START
condition, which is a HIGH to LOW transition of SDA while SCL
is HIGH. The X95820 continuously monitors the SDA and SCL
lines for the START condition and does not respond to any
command until this condition is met (See Figure 15). A START
condition is ignored during the power up sequence and during
internal non-volatile write cycles.
SDA line LOW to acknowledge the reception of the eight bits of
data (See Figure 16).
The X95820 responds with an ACK after recognition of a
START condition followed by a valid Identification Byte, and
once again after successful receipt of an Address Byte. The
X95820 also responds with an ACK after receiving a Data Byte
of a write operation. The master must respond with an ACK
after receiving a Data Byte of a read operation
All I2C interface operations must be terminated by a STOP
condition, which is a LOW to HIGH transition of SDA while SCL
is HIGH (See Figure 15). A STOP condition at the end of a
read operation, or at the end of a write operation to volatile
bytes only places the device in its standby mode. A STOP
condition during a write operation to a non-volatile byte,
initiates an internal non-volatile write cycle. The device enters
its standby state when the internal non-volatile write cycle is
completed.
A valid Identification Byte contains 1010 as the four MSBs, and
the following three bits matching the logic values present at
pins A2, A1, and A0. The LSB in the Read/Write bit. Its value is
“1” for a Read operation, and “0” for a Write operation (See
Table 2).
TABLE 2. IDENTIFICATION BYTE FORMAT
Logic values at pins A2, A1, and A0 respectively
An ACK, Acknowledge, is a software convention used to
indicate a successful data transfer. The transmitting device,
either master or slave, releases the SDA bus after transmitting
eight bits. During the ninth clock cycle, the receiver pulls the
1
0
1
0
A2
A1
A0
(MSB)
R/W
(LSB)
SCL
SDA
START
DATA
STABLE
DATA
CHANGE
DATA
STABLE
STOP
FIGURE 15. VALID DATA CHANGES, START, AND STOP CONDITIONS
SCL from Master
1
8
9
SDA Output from
Transmitter
High Impedance
High Impedance
SDA Output from
Receiver
START
ACK
FIGURE 16. ACKNOWLEDGE RESPONSE FROM RECEIVER
Write
Signals from the
Master
Signal at SDA
Signals from the
X95820
S
t
a
r
t
1 0 1 0 A2A1A00
S
t
o
p
Data
Byte
Address
Byte
Identification
Byte
0 0 0 0
A
C
K
A
C
K
A
C
K
FIGURE 17. BYTE WRITE SEQUENCE
FN8212 Rev 2.00
July 18, 2006
Page 10 of 12
X95820
Write Operation
A Write operation requires a START condition, followed by a
valid Identification Byte, a valid Address Byte, a Data Byte, and
a STOP condition. After each of the three bytes, the X95820
responds with an ACK. At this time, if the Data Byte is to be
written only to volatile registers, then the device enters its
standby state. If the Data Byte is to be written also to nonvolatile memory, the X95820 begins its internal write cycle to
non-volatile memory. During the internal non-volatile write
cycle, the device ignores transitions at the SDA and SCL pins,
and the SDA output is at a high impedance state. When the
internal non-volatile write cycle is completed, the X95820
enters its standby state (See Figure 17).
The byte at address 00001000 bin (8 decimal) determines if
the Data Byte is to be written to volatile and/or non-volatile
memory. See “Memory Description” on page 9.
Data Protection
The WP pin has to be at logic HIGH to perform any Write
operation to the device. When the WP is active (LOW) the
device ignores Data Bytes of a Write Operation, does not
respond to the Data Bytes with an ACK, and instead, goes to
its standby state waiting for a new START condition.
A STOP condition also acts as a protection of non-volatile
memory. A valid Identification Byte, Address Byte, and total
number of SCL pulses act as a protection of both volatile and
non-volatile registers. During a Write sequence, the Data Byte
is loaded into an internal shift register as it is received. If the
Address Byte is 0, 1, or 8 decimal, the Data Byte is transferred
to the appropriate Wiper Register (WR) or to the Access
Signals
from the
Master
S
t
a
r
t
Identification
Byte
with
R/W=0
S
t
a
r
t
Address
Byte
Control Register, at the falling edge of the SCL pulse that loads
the last bit (LSB) of the Data Byte. If the Address Byte is
between 0 and 6 (inclusive), and the Access Control Register
is all zeros (default), then the STOP condition initiates the
internal write cycle to non-volatile memory.
Read Operation
A Read operation consists of a three byte instruction followed
by one or more Data Bytes (See Figure 18). The master
initiates the operation issuing the following sequence: a
START, the Identification byte with the R/W bit set to “0”, an
Address Byte, a second START, and a second Identification
byte with the R/W bit set to “1”. After each of the three bytes,
the X95820 responds with an ACK. Then the X95820 transmits
Data Bytes as long as the master responds with an ACK during
the SCL cycle following the eight bit of each byte. The master
terminates the read operation (issuing a STOP condition)
following the last bit of the last Data Byte (See Figure 18).
The Data Bytes are from the memory location indicated by an
internal pointer. This pointer initial value is determined by the
Address Byte in the Read operation instruction, and
increments by one during transmission of each Data Byte.
After reaching the memory location 01Fh (8 decimal) the
pointer “rolls over” to 00h, and the device continues to output
data for each ACK received.
The byte at address 00001000 bin (8 decimal) determines if
the Data Bytes being read are from volatile or non-volatile
memory. See “Memory Description” on page 9.
Identification
Byte
with
R/W=1
A
C
K
S
t
o
p
A
C
K
Signal at SDA
1 0 1 0
Signals from the
Slave
1 0 1 0
0
A
C
K
A
C
K
1
A
C
K
First Read Data
Byte
Last Read Data
Byte
FIGURE 18. READ SEQUENCE
FN8212 Rev 2.00
July 18, 2006
Page 11 of 12
X95820
Thin Shrink Small Outline Plastic Packages (TSSOP)
M14.173
N
INDEX
AREA
E
0.25(0.010) M
E1
2
SYMBOL
3
0.05(0.002)
-A-
INCHES
GAUGE
PLANE
-B1
14 LEAD THIN SHRINK SMALL OUTLINE PLASTIC
PACKAGE
B M
L
A
D
-C-
e
A2
A1
b
0.10(0.004) M
0.25
0.010
SEATING PLANE
c
0.10(0.004)
C A M
B S
MIN
1. These package dimensions are within allowable dimensions of
JEDEC MO-153-AC, Issue E.
MILLIMETERS
MIN
MAX
NOTES
A
-
0.047
-
1.20
-
A1
0.002
0.006
0.05
0.15
-
A2
0.031
0.041
0.80
1.05
-
b
0.0075
0.0118
0.19
0.30
9
c
0.0035
0.0079
0.09
0.20
-
D
0.195
0.199
4.95
5.05
3
E1
0.169
0.177
4.30
4.50
4
e
0.026 BSC
0.65 BSC
-
E
0.246
0.256
6.25
6.50
-
L
0.0177
0.0295
0.45
0.75
6
8o
0o
N
NOTES:
MAX
14
0o
14
7
8o
Rev. 2 4/06
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Dimension “D” does not include mold flash, protrusions or gate burrs.
Mold flash, protrusion and gate burrs shall not exceed 0.15mm
(0.006 inch) per side.
4. Dimension “E1” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.15mm (0.006 inch) per
side.
5. The chamfer on the body is optional. If it is not present, a visual index
feature must be located within the crosshatched area.
6. “L” is the length of terminal for soldering to a substrate.
7. “N” is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. Dimension “b” does not include dambar protrusion. Allowable dambar
protrusion shall be 0.08mm (0.003 inch) total in excess of “b” dimension at maximum material condition. Minimum space between protrusion and adjacent lead is 0.07mm (0.0027 inch).
10. Controlling dimension: MILLIMETER. Converted inch dimensions
are not necessarily exact. (Angles in degrees)
© Copyright Intersil Americas LLC 2005-2006. All Rights Reserved.
All trademarks and registered trademarks are the property of their respective owners.
For additional products, see www.intersil.com/en/products.html
Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted
in the quality certifications found at www.intersil.com/en/support/qualandreliability.html
Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such
modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets are
current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its
subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Intersil or its subsidiaries.
For information regarding Intersil Corporation and its products, see www.intersil.com
FN8212 Rev 2.00
July 18, 2006
Page 12 of 12
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