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(R)
X95840
Quad Digital Controlled Potentiometers (XDCPTM)
Data Sheet July 5, 2006 FN8213.2
Low Noise/Low Power/I2C(R) Bus/256 Taps
The X95840 integrates four 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 four DCP's IVR to the corresponding WRs. 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.
Features
* Four 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 < 5A Max * Power Supply: 2.7V to 5.5V * 50k, 10k Total Resistance * High Reliability - Endurance: 150,000 data changes per bit per register - Register data retention: 50 years @ T 75C * 20 Ld TSSOP * Pb-Free Plus Anneal Available (RoHS Compliant)
Ordering Information
PART NUMBER X95840WV20I-2.7* PART MARKING X95840WV G RESISTANCE OPTION 10k 10k 50k 50k PACKAGE 20 Ld TSSOP 20 Ld TSSOP (Pb-free) 20 Ld TSSOP 20 Ld TSSOP (Pb-free)
Pinouts
X95840 (20 LD TSSOP) TOP VIEW
RH3 RL3 RW3 A2 SCL SDA 1 2 3 4 5 6 7 8 9 10 20 19 18 17 16 15 14 13 12 11 RW0 RL0 RH0 WP VCC A1 A0 RH1 RL1 RW1
X95840WV20IZ-2.7* X95840WV Z G (Note) X95840UV20I-2.7* X95840UV G
X95840UV20IZ-2.7* X95840UV Z G (Note) *Add "T1" suffix for tape and reel.
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.
GND RW2 RL2 RH2
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. XDCP is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005-2006. All Rights Reserved All other trademarks mentioned are the property of their respective owners.
X95840 Block Diagram
VCC RH3 RW3 RL3 RH2 RW2 RL2 RH1 RW1 RL1 RH0 RW0 RL0
I2C INTERFACE SDA SCL
POWER-UP, INTERFACE, CONTROL AND StAtus LOGIC
WR3
DCP3
WR2 A2 A1 A0 NON-VOLATILE REGISTERS WR0 WR1
DCP2
DCP1
DCP0
WP
GND
Pin Descriptions
TSSOP PIN 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 SYMBOL RH3 RL3 RW3 A2 SCL SDA GND RW2 RL2 RH2 RW1 RL1 RH1 A0 A1 VCC WP RH0 RL0 RW0 "High" terminal of DCP3 "Low" terminal of DCP3 "Wiper" terminal of DCP3 Device address for the I2C interface I2C interface clock Serial data I/O for the I2C interface Device ground pin "Wiper" terminal of DCP2 "Low" terminal of DCP2 "High" terminal of DCP2 "Wiper" terminal of DCP1 "Low" terminal of DCP1 "High" terminal of DCP1 Device address for the I2C interface Device address for the I2C interface Power supply pin Hardware write protection pin. Active low. Prevents any "Write" operation of the I2C interface. "High" terminal of DCP0 "Low" terminal of DCP0 "Wiper" terminal of DCP0 DESCRIPTION
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FN8213.2 July 5, 2006
X95840
Absolute Maximum Ratings
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
Recommended Operating Conditions
Temperature Range (Industrial) . . . . . . . . . . . . . . . . . . -40C to 85C 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. TEST CONDITIONS W, U versions respectively -20 VCC = 3.3V @ 25C Wiper current = VCC/RTOTAL 70 10/10/25 Voltage at pin from GND to VCC 0.1 1 MIN TYP (Note 1) 10, 50 +20 200 MAX UNIT k % pF A
PARAMETER RH to RL Resistance RH to RL Resistance Tolerance
RW CH/CL/CW ILkgDCP
Wiper Resistance Potentiometer Capacitance (Note 15) Leakage on DCP Pins (Note 15)
VOLTAGE DIVIDER MODE (0V @ RLi; VCC @ RHi; measured at RWi, unloaded; i = 0, 1, 2, or 3) INL (Note 6) Integral Non-linearity Monotonic over all tap positions U option W option Full-scale Error U option W option DCP to DCP Matching Any two DCPs at same tap position, same voltage at all RH terminals, and same voltage at all RL terminals DCP Register set to 80 hex -1 -0.5 0 0 -7 -2 -2 1 0.5 -1 -1 1 0.5 7 2 0 0 2 LSB (Note 2) LSB (Note 2) LSB (Note 2) LSB (Note 2) LSB (Note 2) ppm/C
DNL (Note 5) Differential Non-linearity ZSerror (Note 3) FSerror (Note 4) VMATCH (Note 7) Zero-scale Error
TCV (Note 8) Ratiometric Temperature Coefficient
4
RESISTOR MODE (Measurements between RWi and RLi with RHi not connected, or between RWi and RHi with RLi not connected. i = 0, 1, 2 or 3) RINL (Note 12) RDNL (Note 11) Roffset (Note 10) Integral Non-linearity Differential Non-linearity Offset U option W option RMATCH (Note 13) TCR (Note 14) DCP to DCP Matching Resistance Temperature Coefficient Any two DCPs at the same tap position with the same terminal voltages. DCP register set between 20 hex and FF hex DCP register set between 20 hex and FF hex. Monotonic over all tap positions -1 -0.5 0 0 -2 45 1 0.5 1 0.5 7 2 2 MI (Note 9) MI (Note 9) MI (Note 9) MI (Note 9) MI (Note 9) ppm/C
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FN8213.2 July 5, 2006
X95840
Operating Specifications Over the recommended operating conditions unless otherwise specified.
SYMBOL ICC1 ICC2 ISB PARAMETER VCC Supply Current (Volatile write/read) VCC Supply Current (nonvolatile write) VCC Current (standby) TEST CONDITIONS fSCL Active, Read and Volatile Write States only) fSCL = 400kHz; SDA = Open; (for I2C, Active, Nonvolatile Write State only) VCC = +5.5V, I2C Interface in Standby State VCC ILkgDig Leakage Current, at Pins A0, A1, A2, SDA, SCL, and WP Pins DCP Wiper Response Time Power-on Recall Voltage VCC Ramp Rate Power-up Delay VCC above Vpor, to DCP Initial Value Register recall completed, and I2C Interface in standby state = +3.6V, I2C Interface in Standby State -10 = 400kHz; SDA = Open; (for I2C, MIN TYP (Note 1) MAX 1 3 5 2 10 UNITS mA mA A A A
Voltage at pin from GND to VCC
tDCP (Note 15) Vpor VccRamp tD (Note 15)
SCL falling edge of last bit of DCP Data Byte to wiper change Minimum VCC at which memory recall occurs 1.8 0.2
1 2.6
s V V/ms
3
ms
EEPROM SPECS EEPROM Endurance EEPROM Retention SERIAL INTERFACE SPECS VIL WP, A2, A1, A0, SDA, and SCL Input Buffer LOW Voltage WP, A2, A1, A0, SDA, and SCL Input Buffer HIGH Voltage SDA and SCL Input Buffer Hysteresis -0.3 0.3*VCC V Temperature 75C 150,000 50 Cycles Years
VIH
0.7*VCC
VCC+0.3
V
Hysteresis (Note 15)
0.05* VCC 0 0.4 10 400 50 900 1300
V V pF kHz ns ns ns
VOL (Note 15) SDA outPut Buffer LOW Voltage, Sinking 4mA Cpin (Note 15) fSCL tIN (Note 15) WP, A2, A1, A0, SDA, and SCL Pin Capacitance SCL frEquency Pulse Width Suppression Any pulse narrower than the max spec is suppressed. Time at SDA and SCL Inputs SCL falling edge crossing 30% of VCC, until SDA exits the 30% to 70% of VCC window. SDA crossing 70% of VCC during a STOP condition, to SDA crossing 70% of VCC during the following START condition. Measured at the 30% of VCC crossing. Measured at the 70% of VCC crossing. SCL rising edge to SDA falling edge. Both crossing 70% of VCC. From SDA falling edge crossing 30% of VCC to SCL falling edge crossing 70% of VCC.
tAA (Note 15) SCL Falling Edge to SDA Output Data Valid tBUF (Note 15) tLOW tHIGH tSU:STA tHD:STA Time the Bus Must be Free Before the Start of a New Transmission Clock LOW Time Clock HIGH Time START Condition Setup Time START Condition Hold Time
1300 600 600 600
ns ns ns ns
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FN8213.2 July 5, 2006
X95840
Operating Specifications Over the recommended operating conditions unless otherwise specified. (Continued)
SYMBOL tSU:DAT tHD:DAT tSU:STO tHD:STO PARAMETER Input Data Setup Time Input Data Hold Time TEST CONDITIONS From SDA exiting the 30% to 70% of VCC window, to SCL rising edge crossing 30% of VCC From SCL rising edge crossing 70% of VCC to SDA entering the 30% to 70% of VCC window. MIN 100 0 600 600 0 20 + 0.1 * Cb 20 + 0.1 * Cb 10 1 250 250 400 TYP (Note 1) MAX UNITS ns ns ns ns ns ns ns pF k
STOP Condition Setup Time From SCL rising edge crossing 70% of VCC, to SDA rising edge crossing 30% of VCC. STOP Condition Setup Time From SDA rising edge to SCL falling edge. Both crossing 70% of VCC. From SCL falling edge crossing 30% of VCC, until SDA enters the 30% to 70% of VCC window. From 30% to 70% of VCC From 70% to 30% of VCC Total on-chip and off-chip Maximum is determined by tR and tF. For Cb = 400pF, max is about 2~2.5k. For Cb = 40pF, max is about 15~20k
tDH (Note 15) Output Data Hold Time tR (Note 15) tF (Note 15) Cb (Note 15) SDA and SCL Rise Time SDA and SCL Fall Time Capacitive Loading of SDA or SCL
Rpu (Note 15) SDA and SCL Bus Pull-up Resistor Off-chip tWP Non-volatile Write Cycle (Notes 15, 16) Time tSU:WPA tHD:WPA A2, A1, A0, and WP Setup Time A2, A1, A0, and WP Hold Time
12 Before START condition After STOP condition 600 600
20
ms ns ns
SDA vs SCL Timing
tF tHIGH tLOW tR
SCL tSU:STA tHD:STA SDA (INPUT TIMING)
tSU:DAT tHD:DAT tSU:STO
tAA SDA (OUTPUT TIMING)
tDH
tBUF
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FN8213.2 July 5, 2006
X95840
WP, A0, A1, and A2 Pin Timing
START STOP
SCL
Clk 1
SDA IN tSU:WPA WP, A0, A1, or A2 tHD:WPA
NOTES: 1. Typical values are for TA = 25C 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 3 and y = 0 to 3. Max ( V ( RW ) i ) - Min ( V ( RW ) i ) 10 6 8. TC V = --------------------------------------------------------------------------------------------- x ---------------[ Max ( V ( RW ) i ) + Min ( V ( RW ) i ) ] 2 125C for i = 16 to 240 decimal, T = -40C to 85C. 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 3 and y = 0 to 3. [ Max ( Ri ) - Min ( Ri ) ] 10 14. TC R = --------------------------------------------------------------- x ---------------[ Max ( Ri ) + Min ( Ri ) ] 2 125C for i = 32 to 255, T = -40C to 85C. Max( ) is the maximum value of the resistance and Min ( ) is the minimum value of the resistance over the temperature range. 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.
6
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FN8213.2 July 5, 2006
X95840 Typical Performance Curves
160 140 WIPER RESISTANCE () 120 100 80 60 40 20 0 0 VCC = 5.5, T = -40C 50 100 VCC = 5.5, T = 85C VCC = 5.5, T = 25C 150 200 250 STANDBY ICC (A) VCC = 2.7, T = 85C VCC = 2.7, T = -40C VCC = 2.7, T = 25C 1.8 1.6 1.4 1.2 1.0 0.8 0.6 0.4 0.2 0.0 2.7 3.2 25C 3.7 4.2 VCC (V) 4.7 5.2 85C -40C
TAP POSITION (DECIMAL)
FIGURE 1. WIPER RESISTANCE vs TAP POSITION [ I(RW) = VCC/RTOTAL ] FOR 50k (U)
FIGURE 2. STANDBY ICC vs VCC
0.2 0.15 0.1 DNL (LSB) 0.05 0 -0.05 -0.1 -0.15 -0.2 0
0.3 VCC = 5.5, T = -40C VCC = 2.7, T = 25C VCC = 2.7, T = -40C 0.2 0.1 INL (LSB) 0 -0.1 -0.2 -0.3
VCC = 2.7, T = -40C VCC = 5.5, T = -40C
VCC = 5.5, T = 85C
VCC = 2.7, T = 25C VCC = 2.7, T = 85C VCC = 5.5, T = 25C
VCC = 5.5, T = 25C VCC = 2.7, T = 85C VCC = 5.5, T = 85C
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)
0.4
0 -0.1
0.35 FSerror (LSB)
-0.2 -0.3
VCC = 5.5V
ZSerror (LSB)
0.3 2.7V 0.25
-0.4 -0.5 -0.6 -0.7 -0.8 -0.9 VCC = 2.7V
0.2
5.5V
0.15 -40
-20
0
20
40
60
80
-1 -40
-20
0
20
40
60
80
TEMPERATURE (C)
TEMPERATURE (C)
FIGURE 5. ZSerror vs TEMPERATURE
FIGURE 6. FSerror vs TEMPERATURE
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FN8213.2 July 5, 2006
X95840 Typical Performance Curves
(Continued)
0.3 VCC = 2.7, T = 25C 0.2 0.1 DNL (LSB) INL (LSB) 0 -0.1 VCC = 5.5, T = 85C -0.2 -0.3 32 VCC = 2.7, T = 85C VCC = 2.7, T = -40C VCC = 5.5, T = -40C 232 VCC = 5.5, T = 25C
0.5 0.4 0.3 0.2 0.1 0 -0.1 -0.2 -0.3 -0.4 VCC = 2.7, T = 85C VCC = 5.5, T = 25C -0.5 32 82 132 VCC = 2.7, T = -40C 182 232 VCC = 5.5, T = -40C VCC = 5.5, T = 85C VCC = 2.7, T = 25C
82
132 182 TAP POSITION (DECIMAL)
TAP POSITION (DECIMAL)
FIGURE 7. DNL vs TAP POSITION IN Rheostat MODE FOR 50k (U)
FIGURE 8. INL vs TAP POSITION IN Rheostat MODE FOR 50k (U)
1.50 END TO END RTOTAL CHANGE (%) 1.00
20
10 0.50 0.00 5.5V TC (ppm/C) 2.7V
0
-0.50 -1.00 -1.50 -40
-10
-20
0
20
40
60
80
-20 32
82
132
182
232
TEMPERATURE (C)
TAP POSITION (DECIMAL)
FIGURE 9. END TO END RTOTAL % CHANGE vs TEMPERATURE
FIGURE 10. TC FOR VOLTAGE DIVIDER MODE IN ppm
35 INPUT 25 15 TC (ppm/C) 5 -5 -15 -25 32 Tap Position = Mid Point RTOTAL = 9.4K 57 82 107 132 157 182 207 232
OUTPUT
TAP POSITION (DECIMAL)
FIGURE 12. FREQUENCY RESPONSE (2.2MHz)
FIGURE 11. TC FOR Rheostat MODE IN ppm
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FN8213.2 July 5, 2006
X95840 Typical Performance Curves
(Continued)
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)
FIGURE 14. LARGE SIGNAL SETTLING TIME
Principles of Operation
The X95840 in as integrated circuit incorporating four DCPs with their associated registers, non-volatile memory, and a I2C serial interface providing direct communication between a host and the potentiometers and memory.
Memory Description
The X95840 contains eight non-volatile bytes. they are accessed by I2C interface operations with Address Bytes 0 through 7 decimal. The first four non-volatile bytes at addresses 0, 1, 2, and 3, contain the initial value loaded at power-up into the volatile Wiper Registers (WRs) of DCP0, DCP1, DCP2, and DCP3 respectively. Bytes at addresses 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 volatile WR, and the non-volatile Initial Value Register (IVR) of a DCP are accessed with the same Address Byte. A volatile byte at address 8 decimal, controls what byte is read or written when accessing DCP registers: the WR, the IVR, or both. When the byte at address 8 is all zeroes, which is the default at power up: * A read operation to addresses 0, 1, 2 or 3 outputs the value of the non-volatile IVRs. * A write operation to addresses 0, 1, 2, or 3 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, 1, 2, or 3 outputs the value of the volatile WR. * A write operation to addresses 0, 1, 2, or 3 only 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. the value at address 8 must be all zeros.
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<7:0>: 00h), its wiper terminal (RW) is closest to its "Low" terminal (RL). When the WR of a DCP contains all ones (WR<7:0>: 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 X95840 is being powered up, all four 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 X95840 reads the value stored on four 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. To access the general purpose bytes at addresses 4, 5, or 6,
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FN8213.2 July 5, 2006
X95840
The X95840 is pre-programed with 80h in the four IVRs.
TABLE 1. MEMORY MAP ADDRESS 8 7 6 5 4 3 2 1 0 General Purpose NON-VOLATILE -- Reserved Not Available VOLATILE Access Control
Figure 15). A START condition is ignored during the power up sequence and during internal non-volatile write cycles. 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. 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 SDA line LOW to acknowledge the reception of the eight bits of data (See Figure 16). The X95840 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 X95840 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 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
IVR3 IVR2 IVR1 IVR0
WR3 WR2 WR1 WR0
WR: Wiper Register, IVR: Initial value Register.
I2C Serial Interface
The X95840 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 X95840 operates as a slave device in all applications. All communication over the I2C interface is conducted by sending the MSB of each byte of data first.
Protocol Conventions
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 X95840 the SDA pin is in the input mode. All I2C interface operations must begin with a START condition, which is a HIGH to LOW transition of SDA while SCL is HIGH. The X95840 continuously monitors the SDA and SCL lines for the START condition and does not respond to any command until this condition is met (See
1 (MSB)
0
1
0
A2
A1
A0
R/W (LSB)
SCL
SDA
START
DATA STABLE
DATA CHANGE
DATA STABLE
STOP
FIGURE 15. VALID DATA CHANGES, START, AND STOP CONDITIONS
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FN8213.2 July 5, 2006
X95840
SCL from Master 1 8 9
SDA Output from Transmitter
High Impedance
SDA Output from Receiver
High Impedance
START
ACK
FIGURE 16. ACKNOWLEDGE RESPONSE FROM RECEIVER
Write Signals from the Master S t a r t S t o p
Identification Byte
Address Byte
Data Byte
Signal at SDA Signals from the X95840
1 0 1 0 A2A1A00 A C K
0000 A C K A C K
FIGURE 17. BYTE WRITE SEQUENCE
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 X95840 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 non-volatile memory, the X95840 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 X95840 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.
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, 2, 3, or 8 decimal, the Data Byte is transferred to the appropriate Wiper Register (WR) or to the Access 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 consist 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 X95840 responds with an ACK. Then the X95840 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
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.
11
FN8213.2 July 5, 2006
X95840
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 08h (8 decimal) the
S t a r t Identification Byte with R/W=0 S t a r t
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.
Signals from the Master
Address Byte
Identification Byte with R/W=1
A C K
A C K
S t o p
Signal at SDA
10 10
0
A C K A C K
10 10
1
A C K First Read Data Byte Last Read Data Byte
Signals from the Slave
FIGURE 18. READ SEQUENCE
12
FN8213.2 July 5, 2006
X95840 Thin Shrink Small Outline Package Family (TSSOP)
0.25 M C A B D N (N/2)+1 A
MDP0044
THIN SHRINK SMALL OUTLINE PACKAGE FAMILY SYMBOL 14 LD 16 LD 20 LD 24 LD 28 LD TOLERANCE A
PIN #1 I.D.
1.20 0.10 0.90 0.25 0.15 5.00 6.40 4.40 0.65 0.60 1.00
1.20 0.10 0.90 0.25 0.15 5.00 6.40 4.40 0.65 0.60 1.00
1.20 0.10 0.90 0.25 0.15 6.50 6.40 4.40 0.65 0.60 1.00
1.20 0.10 0.90 0.25 0.15 7.80 6.40 4.40 0.65 0.60 1.00
1.20 0.10 0.90 0.25 0.15 9.70 6.40 4.40 0.65 0.60 1.00
Max 0.05 0.05 +0.05/-0.06 +0.05/-0.06 0.10 Basic 0.10 Basic 0.15 Reference Rev. E 12/02
A1 A2 b c D E E1 e L
H
E
E1
0.20 C B A 1 B TOP VIEW (N/2) 2X N/2 LEAD TIPS
C SEATING PLANE
e
0.05
L1 NOTES:
b 0.10 C N LEADS SIDE VIEW
0.10 M C A B
1. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed 0.15mm per side. 2. Dimension "E1" does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm per side. 3. Dimensions "D" and "E1" are measured at dAtum Plane H. 4. Dimensioning and tolerancing per ASME Y14.5M-1994.
SEE DETAIL "X"
c
END VIEW
L1
A
A2 GAUGE PLANE 0.25 A1 DETAIL X L 0 - 8
All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation's quality certifications can be viewed at www.intersil.com/design/quality
Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets 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 13
FN8213.2 July 5, 2006

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