ISL95311 ® Digitally Controlled Potentiometer (XDCP™) Data Sheet February 6, 2008 Terminal Voltage 0V to 13.2V, 128 Taps I2C Interface Features The Intersil ISL95311 is a digitally controlled potentiometer (XDCP). The device consists of a resistor array, wiper switches, a control section, and nonvolatile memory. The wiper position is controlled by an I2C interface. • I2C serial interface The potentiometer is implemented by a resistor array composed of 127 resistive elements and a wiper switching network. Between each element and at either end are tap points accessible to the wiper terminal. The wiper of the potentiometer has an associated volatile Wiper Counter 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 on the resistor array through the switches. At power-up, the device recalls the contents of the IVR to the corresponding WR. The device can be used as a three-terminal potentiometer or as a two-terminal variable resistor in a wide variety of applications, including: FN8084.1 • Non-volatile solid-state potentiometer • DCP terminal voltage, 0V to +13.2V • 128 wiper tap points - 0.8% resolution - Wiper position stored in nonvolatile memory and recalled on power-up • 127 resistive elements - Temperature compensated - Low wiper resistance 70Ω typical @ 3.3V • Low power CMOS - Standby current, 2µA @ VCC = +3.6V • High reliability - Endurance, 200,000 data changes per bit - Register data retention 50 years @ T ≤ +75°C • RTOTAL values = 10kΩ, 50kΩ • 10 Ld MSOP package • LCD contrast control • Pb-free (RoHS compliant) • Parameter and bias adjustments Pinout • Industrial and automotive control ISL95311 (10-LD MSOP) TOP VIEW • Mechanical pot replacement SCL SDA 1 10 GND 2 9 V+ VCC 3 8 RL A1 4 7 RW A0 5 6 RH Ordering Information PART NUMBER (Note) PART MARKING RESISTANCE OPTION (Ω) TEMP RANGE (°C) PACKAGE (Pb-Free) PKG. DWG. # ISL95311WIU10Z AJE 10k -40 to +85 10-Ld MSOP M10.118 ISL95311UIU10Z AJD 50k -40 to +85 10-Ld MSOP M10.118 Add “-TK” suffix for tape and reel. Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate PLUS ANNEAL - e3 termination finish, which is 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. 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, 2008. All Rights Reserved All other trademarks mentioned are the property of their respective owners. ISL95311 Block Diagram SDA SCL V+ VCC 7-BIT WIPER REGISTER (VOLATILE) RH 127 126 SDA 125 RH SCL A1 CONTROL AND MEMORY 7-BIT NONVOLATILE MEMORY RW A0 124 ONE OF 128 TRANSFER GATES RESISTOR ARRAY DECODER RL 2 STORE AND RECALL CONTROL CIRCUITRY GND SIMPLE BLOCK DIAGRAM A1 A0 1 0 RL RW SLAVE ADDRESS DECODE DETAILED BLOCK DIAGRAM Pin Descriptions PIN NUMBER SYMBOL DESCRIPTION 1 SDA Data I/O for I2C serial interface; it has an open drain output and may be wire-or’d with other open drain active low outputs 2 GND Ground 3 VCC Positive logic supply voltage 4 A1 Address select pin used to set the slave address for the I2C serial interface 5 A0 Address select pin used to set the slave address for the I2C serial interface 6 RH A fixed terminal for one end of the potentiometer resistor 7 RW The wiper terminal, which is equivalent to the movable terminal of a potentiometer 8 RL A fixed terminal for one end of the potentiometer resistor 9 V+ Positive bias voltage for the potentiometer wiper control 10 SCL 2 Clock input for the I2C serial interface FN8084.1 February 6, 2008 ISL95311 Absolute Maximum Ratings Recommended Operating Conditions Storage temperature . . . . . . . . . . . . . . . . . . . . . . . .-65°C to +150°C Voltage on SDA, SCL, A0, A1 with respect to GND . . . . . . . . . . . . . . . . . . . . -0.3V to VCC + 0.3V Voltage on V+ (referenced to GND) . . . . . . . . . . . . . . . . . . . . +13.2V ΔV = |V(RH) - V(RL)| . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .V+ RH, RL, RW . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .V+ IW (10s) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±6mA VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V Power rating of DCP . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .20mW Temperature Range (Industrial) . . . . . . . . . . . . . . . . .-40°C to +85°C VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2.7V to 5.5V V+ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8.0V to 13.2V Wiper current of DCP. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±3.0mA Pb-free reflow profile . . . . . . . . . . . . . . . . . . . . . . . . . .see link below http://www.intersil.com/pbfree/Pb-FreeReflow.asp CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. Analog Specifications Over recommended operating conditions, unless otherwise stated. SYMBOL RTOTAL MIN TYP MAX (Note 15) (Note 1) (Note 15) UNIT W option 10 kΩ U option 50 kΩ PARAMETER RH to RL Resistance TEST CONDITIONS RH to RL Resistance Tolerance VRH RH Terminal Voltage VRL = 0V RW Wiper Resistance V+ = 12.0V, wiper current = V+/RTOTAL CH/CL/CW ILkgDCP -20 +20 % 0 V+ V 200 Ω 70 Potentiometer Capacitance Leakage on DCP Pins 10/10/25 Voltage at pin from GND to V+ 0.1 pF 1 µA VOLTAGE DIVIDER MODE (0V @ RL; V+ @ RH; measured at RW, unloaded) INL (Note 6) Integral Non-Linearity W and U option -1 1 LSB (Note 2) DNL (Note 5) Differential Non-Linearity W and U option -0.5 0.5 LSB (Note 2) ZSerror (Note 3) Zero-Scale Error W option 0 1 7 U option 0 0.5 2 LSB (Note 2) FSerror (Note 4) Full-Scale Error W option -7 -1 0 U option -2 -0.5 0 TCV (Note 7) Ratiometric Temperature Coefficient DCP register set to 40 hex ±4 LSB (Note 2) ppm/°C RESISTOR MODE (Measurements between RW and RL with RH not connected, or between RW and RH with RL not connected) RINL (Note 11) Integral Non-Linearity DCP register set between 20 hex and 7F hex; monotonic over all tap positions -1.0 1.0 MI (Note 8) RDNL (Note 10) Differential Non-Linearity W and U option -0.5 0.5 MI (Note 8) Roffset (Note 9) Offset DCP Register set to 00 hex, W option 0 1 7 DCP Register set to 00 hex, U option 0 0.5 2 MI (Note 8) TCR (Note 12) Resistance Temperature Coefficient 3 DCP register set between 20 hex and 7F hex ±45 ppm/°C FN8084.1 February 6, 2008 ISL95311 Operating Specifications Over the recommended operating conditions unless otherwise specified. SYMBOL PARAMETER TEST CONDITIONS MIN TYP MAX (Note 15) (Note 1) (Note 15) UNIT ICC1 VCC Supply Current, Volatile Write/read fSCL = 400kHz; SDA = Open; (for I2C, active, read, and volatile write states only) 1 mA ICC2 VCC Supply Current, Nonvolatile Write fSCL = 400kHz; SDA = Open; (for I2C, active, nonvolatile write states only) 3 mA VCC Current, Standby VCC = +5.5V, I2C interface in standby state 5 µA VCC = +3.6V, I2C interface in standby state 2 µA V+ Bias Current V+ = 13.2V, VCC = +5.5V 1 µA Leakage Current, at Pins SDA, SCL, A0, and A1 Pins Voltage at pin from GND to VCC 10 µA tDCP DCP Wiper Response Time SCL falling edge of last bit of DCP data byte to wiper change 1 µs Vpor Power-On Recall Voltage VCC range at which memory recall occurs ISB IV+ ILkgDig VCCRamp VCC Ramp Rate tD Power-Up Delay -10 1.5 1.8 2.6 V 0.2 V/ms 3 VCC above Vpor, to DCP initial value register recall completed, and I2C Interface in standby state ms EEPROM SPECS EEPROM Endurance EEPROM Retention Temperature ≤ +75°C 200,000 Cycles 50 Years SERIAL INTERFACE SPECS VIL A0, A1, SDA, and SCL Input Buffer LOW Voltage -0.3 0.3* VCC V VIH A0, A1, SDA, and SCL Input Buffer HIGH Voltage 0.7* VCC VCC+ 0.3 V SDA and SCL Input Buffer Hysteresis 0.05* VCC Hysteresis VOL SDA Output Buffer LOW Voltage, Sinking 4mA Cpin A0, A1, SDA, and SCL Pin Capacitance fSCL SCL Frequency V 0 0.4 10 tIN Pulse Width Suppression Time at SDA and SCL Inputs Any pulse narrower than the max spec is suppressed tAA SCL Falling Edge to SDA Output Data SCL falling edge crossing 30% of VCC, until Valid SDA exits the 30% to 70% of VCC window V pF 400 kHz 50 ns 900 ns tBUF Time the Bus Must be Free Before the SDA crossing 70% of VCC during a STOP Start of a New Transmission 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 Set-up 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 tSU:DAT Input Data Set-up Time From SDA exiting the 30% to 70% of VCC window, to SCL rising edge crossing 30% of VCC 100 ns 4 FN8084.1 February 6, 2008 ISL95311 Operating Specifications Over the recommended operating conditions unless otherwise specified. (Continued) SYMBOL PARAMETER TEST CONDITIONS MIN TYP MAX (Note 15) (Note 1) (Note 15) UNIT tHD:DAT Input Data Hold Time From SCL rising edge crossing 30% of VCC to SDA entering the 30% to 70% of VCC window 0 ns tSU:STO STOP Condition Set-up time From SCL rising edge crossing 70% of VCC, to SDA rising edge crossing 30% of VCC 600 ns tHD:STO STOP Condition Hold Time From SDA rising edge to SCL falling edge. Both crossing 70% of VCC 600 ns Output Data Hold Time From SCL falling edge crossing 30% of VCC, until SDA enters the 30% to 70% of VCC window 0 ns tR (Note 14) SDA and SCL Rise Time From 30% to 70% of VCC 20 + 0.1 * Cb 250 ns tF (Note 14) SDA and SCL Fall Time From 70% to 30% of VCC 20 + 0.1 * Cb 250 ns Cb (Note 14) Capacitive Loading of SDA or SCL Total on-chip and off-chip 10 400 pF Rpu (Note 14) SDA and SCL Bus Pull-Up Resistor Off-Chip Maximum is determined by tR and tF, For Cb = 400pF, max is about 2kΩ~2.5kΩ. For Cb = 40pF, max is about 15kΩ~20kΩ. 1 tWP (Notes 13) Non-Volatile Write Cycle Time tDH kΩ 12 20 ms tSU:A A0, A1 Set-up Time Before START condition 600 ns tHD:A A0, A1 Hold Time After STOP condition 600 ns NOTES: 1. Typical values are for TA = +25°C and 3.3V supply voltage. 2. LSB: [V(RW)127 – V(RW)0]/127. V(RW)127 and V(RW)0 are V(RW) for the DCP register set to 7F 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)127 – V+]/LSB. 5. DNL = [V(RW)i – V(RW)i-1]/LSB-1, for i = 1 to 127. i is the DCP register setting. 6. INL = V(RW)i – (i • LSB – V(RW)0) for i = 1 to 127. Max ( V ( RW ) i ) – Min ( V ( RW ) i ) 10 6 7. TC V = ---------------------------------------------------------------------------------------------- × ----------------[ Max ( V ( RW ) i ) + Min ( V ( RW ) i ) ] ⁄ 2 125°C for i = 16 to 120 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. 8. MI = |R127 – R0|/127. R127 and R0 are the measured resistances for the DCP register set to 7F hex and 00 hex respectively. 9. Roffset = R0/MI, when measuring between RW and RL. Roffset = R127/MI, when measuring between RW and RH. 10. RDNL = (Ri – Ri-1)/MI, for i = 16 to 127. 11. RINL = [Ri – (MI • i) – R0]/MI, for i = 16 to 127. 6 [ Max ( Ri ) – Min ( Ri ) ] 10 12. TC R = ---------------------------------------------------------------- × ----------------[ Max ( Ri ) + Min ( Ri ) ] ⁄ 2 125°C for i = 16 to 127, 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. 13. tWP 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. 14. Recommended operating limits and are not production tested. 15. Parts are 100% tested at +85°C. Over temperature limits established by characterization and are not production tested. 5 FN8084.1 February 6, 2008 ISL95311 SDA vs SCL Timing tF SCL tHIGH tLOW tR tSU:DAT tSU:STA tHD:DAT tSU:STO tHD:STA SDA (INPUT TIMING) tAA tDH tBUF SDA (OUTPUT TIMING) A0, A1 Pin Timing STOP START SCL CLK 1 SDA IN tSU:A tHD:A A0, A1 Pin Descriptions DEVICE ADDRESS (A1–A0) Potentiometer Pins RH and RL RL and RH are referenced to the relative position of the wiper and not the voltage potential on the terminals. With WR set to 127, the wiper will be closest to RH, and with the WR set to 00, the wiper is closest to RL. RW RW is the wiper terminal and is equivalent to the movable terminal of a mechanical potentiometer. The position of the wiper within the array is determined by the WR. Bus Interface Pins SERIAL DATA INPUT/OUTPUT (SDA) The SDA is a bidirectional serial data input/output pin for the I2C interface. It receives device address, operation code, wiper register address and data from a I2C external master device at the rising edge of the serial clock SCL, and it shifts out data after each falling edge of the serial clock SCL. SDA requires an external pull-up resistor, since it’s an open drain input/output. SERIAL CLOCK (SCL) This input is the serial clock of the I2C serial interface. SCL requires an external pull-up resistor, since it’s an open drain input. 6 The Address inputs are used to set the least significant 2 bits of the 8-bit I2C interface slave address. A match in the slave address serial data stream must be made with the Address input pins in order to initiate communication with the ISL95311. A maximum of four ISL95311 devices may occupy the I2C serial bus. Principles of Operation The ISL95311 is an integrated circuit incorporating one DCP with their associated register, non-volatile memory, and a I2C serial interface providing direct communication between a host and the potentiometers and memory. The resistor array is comprised of 127 individual resistors connected in series. At either end of the array and between each resistor is an electronic switch between that point and the wiper. The wiper, when at either fixed terminal, acts like its mechanical equivalent and does not move beyond the last position. That is, the counter does not wrap around when clocked to either extreme. The electronic switches on the device operate in a “make before break” mode when the wiper changes tap positions. When the device is powered-down, the last wiper position stored will be maintained in the nonvolatile memory. When power is restored, the contents of the memory are recalled and the wiper is set to the value last stored. FN8084.1 February 6, 2008 ISL95311 On applying power to the ISL95311, the VCC supply should have a monotonic ramp to the specified operating voltage. It is important that once VCC reaches 1V that it increases to at least 2.5V in less than 7.5ms (0.2V/ms). The ramp rate before and after these thresholds is not important. VCC must be applied prior to, or simultaneously, with V+. Under no condition should V+ be applied without VCC. While the sequence of applying V+ and VCC to the ISL95311 does not affect the proper recall of the wiper position, applying V+ before VCC powers the electronic switches of the DCP before the electronic switch control signals are applied. This can result in multiple electronic switches being turned on, which could load the power supply and cause brief, unexpected potentiometer wiper settings. To prevent unknown wiper positions on the ISL95311 on power-down, it is recommended that V+ turn off before or simultaneously with VCC. If V+ remains on after VCC turns off, the wiper position can remain unchanged from its previous setting or it can go to an undefined state. DCP Description The DCP is implemented with a combination of resistor elements and CMOS switches. The physical ends of the DCP are equivalent to the fixed terminals of a mechanical potentiometer (RH and RL pins). The RW pin 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 a 7-bit volatile Wiper Register (WR). When the WR contains all zeroes (00h), the wiper terminal (RW) is closest to its “Low” terminal (RL). When the WR contains all ones (7Fh), the wiper terminal (RW) is closest to its “High” terminal (RH). As the value of the WR increases from all zeroes (00h) to all ones (7Fh), the wiper moves monotonically from the position closest to RL to the position 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 ISL95311 is being powered up, the WR is reset to 20h (64 decimal), which locates the RW at the center between RL and RH. Soon after the power supply voltage becomes large enough for reliable non-volatile memory reading, the ISL95311 reads the value stored on a non-volatile Initial Value Register (IVR) and loads it into the WR. The WR and IVR can be read from or written to directly using the I2C serial interface as described in the following sections. Memory Description The ISL95311 contains 1 non-volatile byte know as the Initial Value Register (IVR). It is accessed by the I2C interface operations with Address 00h. The IVR contains the value which is loaded into the Volatile Wiper Register (WR) at power-up. 7 The volatile WR, and the non-volatile IVR of a DCP are accessed with the same address. The Access Control Register (ACR) determines which word at address 00h is accessed (IVR or WR). The volatile ACR must be set as follows: When the ACR is all zeroes, which is the default at power-up: • A read operation to address 0 outputs the value of the non-volatile IVR. • A write operation to address 0 writes the identical values to the WR and IVR of the DCP. • When the ACR is 80h: • A read operation to address 0 outputs the value of the volatile WR. • A write operation to address 0 only writes to the volatile WR. It is not possible to write to an IVR without writing the same value to its WR. 00h and 80h are the only values that should be written to address 2. All other values are reserved and must not be written to address 2. TABLE 1. MEMORY MAP ADDRESS NON-VOLATILE VOLATILE 2 - ACR 1 0 Reserved IVR WR WR: Wiper Register, IVR: Initial value Register. The ISL95311 is pre-programmed with 40h in the IVR. I2C Serial Interface The ISL95311 supports a bidirectional 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 ISL95311 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 1). On power-up of the ISL95311, 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 FN8084.1 February 6, 2008 ISL95311 SCL is HIGH. The ISL95311 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 1). 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 1). 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 2). The ISL95311 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 ISL95311 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 01010 as the five MSBs, and the following two bits matching the logic values present at pins A1, and A0. The LSB is in the Read/Write bit. Its value is “1” for a Read operation, and “0” for a Write operation (see Table 2.) The byte at address 02h determines if the Data Byte is to be written to volatile and/or non-volatile memory (see “Memory Description” on page 7). Data Protection 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 or 2, the Data Byte is transferred to the Wiper Register (WR) or to the Access Control Register respectively, at the falling edge of the SCL pulse that loads the last bit (LSB) of the Data Byte. If the Address Byte is 0, 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 4). 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 ISL95311 responds with an ACK; then the ISL95311 transmits the Data Byte. The master then terminates the read operation (issuing a STOP condition) following the last bit of the Data Byte (See Figure 4). The byte at address 02h determines if the Data Bytes being read are from volatile or non-volatile memory. (see “Memory Description” on page 7.) LOGIC VALUES AT PINS A1, AND A0 RESPECTIVELY 0 1 0 1 0 A1 A0 (MSB) R/W (LSB) TABLE 2. DENTIFICATION BYTE FORMAT 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 (see Figure 3). After each of the three bytes, the ISL95311 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 ISL95311 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 ISL95311 enters its standby state. 8 FN8084.1 February 6, 2008 ISL95311 SCL SDA START DATA STABLE DATA CHANGE DATA STABLE STOP FIGURE 1. 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 2. ACKNOWLEDGE RESPONSE FROM RECEIVER WRITE SIGNALS FROM THE MASTER SIGNAL AT SDA S T A R T IDENTIFICATION BYTE ADDRESS BYTE 0 1 0 1 0 A1 A0 0 SIGNALS FROM THE ISL95311 S T O P DATA BYTE 0 0 0 0 0 0 0 A C K A C K A C K FIGURE 3. BYTE WRITE SEQUENCE SIGNALS FROM THE MASTER S T A R T SIGNAL AT SDA IDENTIFICATION BYTE WITH R/W = 0 ADDRESS BYTE 0 1 0 1 0 A1 A0 0 0 0 0 0 0 0 A C K SIGNALS FROM THE SLAVE S T A IDENTIFICATION R BYTE WITH T R/W = 1 A C K S T O P A C K 0 1 0 1 0 A1 A0 1 0 A C K A C K FIRST READ DATA BYTE LAST READ DATA BYTE FIGURE 4. READ SEQUENCE 9 FN8084.1 February 6, 2008 ISL95311 Communicating with the ISL95311 Register Description: IVR and WR There are 3 register addresses in the ISL95311, of which two can be used. Address 00h and address 02h are used to control the device. Address 01h is reserved and should not be used. Address 00h contains the nonvolatile Initial Value Register (IVR), and the volatile Wiper Register (WR). Address 02h contains only a volatile word and is used as a pointer to either the IVR or WR. See Table 1. The ISL95311 has a single potentiometer. The wiper of the potentiometer is controlled directly by the WR. Writes and reads can be made directly to this register to control and monitor the wiper position without any nonvolatile memory changes. This is done by setting address 02h to data 80h, then writing the data. The nonvolatile IVR stores the power-up value of the wiper. On power-up, the contents of the IVR are transferred to the WR. Register Descriptions: Access Control The Access Control Register (ACR) is volatile and is at address 02h. It is 8-bits, and only the MSB is significant, all other bits should be zero (0). The ACR controls which word is accessed at register 00h as follows: To write to the IVR, first address 02h is set to data 00h, then the data is written. Writing a new value to the IVR register will set a new power-up position for the wiper. Also, writing to this register will load the same value into the WR as the IVR. So, if a new value is loaded into the IVR, not only will the non-volatile IVR change, but the WR will also contain the same value after the write, and the wiper position will change. Reading from the IVR will not change the WR, if its contents are different. 00h = Nonvolatile IVR 80h = Volatile WR All other bits of the ACR should be written to as zeros. Only the MSB can be either 0 or 1. Power-up default for this address is 00h. Example 1 WRITING A NEW VALUE (77H) TO THE IVR: Write to ACR first 0 1 0 1 0 0 0 0 A 0 0 0 0 0 0 1 0 A 0 0 0 0 0 0 0 0 A 0 0 0 A 0 0 0 0 0 0 0 0 A 0 1 1 1 0 1 1 1 A 0 0 1 0 A Then, write to IVR 0 1 0 1 0 (Note that the WR will also reflect this new value since both registers get written to at the same time) Example 2 READING FROM THE WR: Write to the ACR first (to index the WR) 0 1 0 1 0 0 0 0 A 0 0 0 0 0 0 1 0 A A 0 0 0 0 Then, Set the WR address 0 1 0 1 0 0 0 0 A 0 0 0 0 0 0 0 0 0 0 1 A x x x x x x x x Read from the WR 0 1 0 1 0 Notes: A = acknowledge, x = data bit read 10 FN8084.1 February 6, 2008 ISL95311 Mini Small Outline Plastic Packages (MSOP) N M10.118 (JEDEC MO-187BA) 10 LEAD MINI SMALL OUTLINE PLASTIC PACKAGE E1 INCHES E -B- INDEX AREA 1 2 0.20 (0.008) A B C TOP VIEW 4X θ 0.25 (0.010) R1 R GAUGE PLANE A SEATING PLANE -C- A2 A1 b -He D 0.10 (0.004) 4X θ L SEATING PLANE C 0.20 (0.008) MIN MAX MIN MAX NOTES A 0.037 0.043 0.94 1.10 - A1 0.002 0.006 0.05 0.15 - A2 0.030 0.037 0.75 0.95 - b 0.007 0.011 0.18 0.27 9 c 0.004 0.008 0.09 0.20 - D 0.116 0.120 2.95 3.05 3 E1 0.116 0.120 2.95 3.05 4 0.020 BSC C a CL E1 0.20 (0.008) C D - 0.187 0.199 4.75 5.05 - L 0.016 0.028 0.40 0.70 6 0.037 REF N C 0.50 BSC E L1 -A- SIDE VIEW SYMBOL e L1 MILLIMETERS 0.95 REF 10 R 0.003 R1 - 10 - 0.07 0.003 - θ 5o 15o α 0o 6o 7 - - 0.07 - - 5o 15o - 0o 6o -B- Rev. 0 12/02 END VIEW NOTES: 1. These package dimensions are within allowable dimensions of JEDEC MO-187BA. 2. Dimensioning and tolerancing per ANSI Y14.5M-1994. 3. Dimension “D” does not include mold flash, protrusions or gate burrs and are measured at Datum Plane. 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 and are measured at Datum Plane. - H - Interlead flash and protrusions shall not exceed 0.15mm (0.006 inch) per side. 5. Formed leads shall be planar with respect to one another within 0.10mm (.004) at seating Plane. 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. Datums -A -H- . and - B - to be determined at Datum plane 11. Controlling dimension: MILLIMETER. Converted inch dimensions are for reference only 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 11 FN8084.1 February 6, 2008