APPLICATION NOTES A V A I L A B L E AN99 * AN115 * AN120 * AN124 * AN133 * AN134 * AN135 Low Noise/Low Power/2-Wire Bus X9418 Dual Digitally Controlled Potentiometers (XDCPTM) FEATURES DESCRIPTION * Two potentiometers in one package * 2-wire serial interface * Register oriented format --Direct Read/Write/Transfer Wiper Position --Store as many as Four Positions per Potentiometer * Power supplies --VCC = 2.7V to 5.5V --V+ = 2.7V to 5.5V --V- = -2.7V to -5.5V * Low power CMOS --Standby current < 1A --Ideal for Battery Operated Applications * High reliability --Endurance-100,000 Data Changes per Bit per Register --Register Data Retention-100 years * 8-bytes of nonvolatile memory * 2.5K, 10K resistor array * Resolution: 64 taps each potentiometer * 24-pin plastic DIP, 24-lead TSSOP and 24-lead SOIC packages The X9418 integrates two digitally controlled potentiometers (XDCP) on a monolithic CMOS integrated microcircuit. The digitally controlled potentiometer is implemented using 63 resistive elements in a series array. Between each element are tap points connected to the wiper terminal through switches. The position of the wiper on the array is controlled by the user through the 2-wire bus interface. Each potentiometer has associated with it a volatile Wiper Counter Register (WCR) and 4 nonvolatile Data Registers (DR0:DR3) that can be directly written to and read by the user. The contents of the WCR controls the position of the wiper on the resistor array through the switches. Power up recalls the contents of DR0 to the WCR. The XDCP can be used as a three-terminal potentiometer or as a two-terminal variable resistor in a wide variety of applications including control, parameter adjustments, and signal processing. BLOCK DIAGRAM VCC V+ VSS V- R0 R1 WP R2 R3 SCL SDA A0 A1 A2 A3 VL0/RL0 VW0/RW0 Interface and Control Circuitry 8 VW1/RW1 Data R0 R1 R2 R3 REV 1.1.5 7/23/02 VH0/RH0 Wiper Counter Register (WCR) www.xicor.com Wiper Counter Register (WCR) Resistor Array XDCP1 VH1/RH1 VL1/RL1 Characteristics subject to change without notice. 1 of 21 X9418 PIN DESCRIPTIONS PIN CONFIGURATION Host Interface Pins DIP/SOIC VCC RL0/VL0 RH0/VH0 RW0/VW0 A2 WP SDA A1 RL1/VL1 RH1/VH1 RW1/VW1 Serial Clock (SCL) The SCL input is used to clock data into and out of the X9418. Serial Data (SDA) SDA is a bidirectional pin used to transfer data into and out of the device. It is an open drain output and may be wire-ORed with any number of open drain or open collector outputs. An open drain output requires the use of a pull-up resistor. For selecting typical values, refer to the guidelines for calculating typical values on the bus pull-up resistors graph. VSS 1 24 2 23 3 22 4 21 5 20 6 19 X9418 7 18 8 17 9 16 10 5 14 11 12 13 V+ NC NC NC A0 NC A3 SCL NC NC NC V- TSSOP Device Address (A0-A3) SDA A1 RL1/VL1 RH1/VH1 RW1/VW1 VSS NC NC NC VSCL A3 The Address inputs are used to set the least significant 4 bits of the 8-bit slave address. A match in the slave address serial data stream must be made with the Address input in order to initiate communication with the X9418. A maximum of 16 devices may occupy the 2-wire serial bus. Potentiometer Pins VH/RH (VH0/RH0--VH1/RH1), VL/RL (VL0/RL0--VL1/RL1) The VH/RH and VL/RL inputs are equivalent to the terminal connections on either end of a mechanical potentiometer. 1 24 2 23 3 22 4 21 5 20 6 19 X9418 7 18 8 17 9 16 10 15 14 11 13 12 WP A2 VW0/RW0 VH0/RH0 VL0/RL0 VCC NC NC NC V+ A0 NC PIN NAMES VW/RW (VW0/RW0--VW1/RW1) The wiper outputs are equivalent to the wiper output of a mechanical potentiometer. Hardware Write Protect Input (WP) The WP pin when low prevents nonvolatile writes to the Data Registers. Analog Supplies V+, VThe Analog Supplies V+, V- are the supply voltages for the XDCP analog section. REV 1.1.5 7/23/02 Symbol Description SCL Serial Clock SDA Serial Data A0-A3 Device Address VH0/RH0-VH1/RH1, VL0/RL0-VL1/RL1 Potentiometer Pins (terminal equivalent) VW0/RW0-VW1/RW1 Potentiometer Pins (wiper equivalent) WP Hardware Write Protection V+,V- Analog Supplies VCC System Supply Voltage VSS System Ground NC No Connection www.xicor.com Characteristics subject to change without notice. 2 of 21 X9418 PRINCIPLES OF OPERATION The X9418 is a highly integrated microcircuit incorporating two resistor arrays and their associated registers and counters and the serial interface logic providing direct communication between the host and the XDCP potentiometers. Serial Interface The X9418 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 will always initiate data transfers and provide the clock for both transmit and receive operations. Therefore, the X9418 will be considered a slave device in all applications. Clock and Data Conventions Data states on the SDA line can change only during SCL LOW periods (tLOW). SDA state changes during SCL HIGH are reserved for indicating start and stop conditions. Start Condition All commands to the X9418 are preceded by the start condition, which is a HIGH to LOW transition of SDA while SCL is HIGH (tHIGH). The X9418 continuously monitors the SDA and SCL lines for the start condition and will not respond to any command until this condition is met. Stop Condition All communications must be terminated by a stop condition, which is a LOW to HIGH transition of SDA while SCL is HIGH. Acknowledge Acknowledge is a software convention used to provide a positive handshake between the master and slave devices on the bus to indicate the successful receipt of data. The transmitting device, either the master or the slave, will release the SDA bus after transmitting eight bits. The master generates a ninth clock cycle and during this period the receiver pulls the SDA line LOW to acknowledge that it successfully received the eight bits of data. REV 1.1.5 7/23/02 The X9418 will respond with an acknowledge after recognition of a start condition and its slave address and once again after successful receipt of the command byte. If the command is followed by a data byte the X9418 will respond with a final acknowledge. Array Description The X9418 is comprised of two resistor arrays. Each array contains 63 discrete resistive segments that are connected in series. The physical ends of each array are equivalent to the fixed terminals of a mechanical potentiometer (VH/RH and VL/RL inputs). At both ends of each array and between each resistor segment is a CMOS switch connected to the wiper (VW/RW) output. Within each individual array only one switch may be turned on at a time. These switches are controlled by the Wiper Counter Register (WCR). The six bits of the WCR are decoded to select, and enable, one of sixty-four switches. The WCR may be written directly, or it can be changed by transferring the contents of one of four associated Data Registers into the WCR. These Data Registers and the WCR can be read and written by the host system. Device Addressing Following a start condition the master must output the address of the slave it is accessing. The most significant four bits of the slave address are the device type identifier (refer to Figure 1 below). For the X9418 this is fixed as 0101[B]. Figure 1. Slave Address Device Type Identifier 0 1 0 1 A3 A2 A1 A0 Device Address The next four bits of the slave address are the device address. The physical device address is defined by the state of the A0-A3 inputs. The X9418 compares the serial data stream with the address input state; a successful compare of all four address bits is required for the X9418 to respond with an acknowledge. The A0-A3 inputs can be actively driven by CMOS input signals or tied to VCC or VSS. www.xicor.com Characteristics subject to change without notice. 3 of 21 X9418 Acknowledge Polling The disabling of the inputs, during the internal nonvolatile write operation, can be used to take advantage of the typical 5ms EEPROM write cycle time. Once the stop condition is issued to indicate the end of the nonvolatile write command the X9418 initiates the internal write cycle. ACK polling can be initiated immediately. This involves issuing the start condition followed by the device slave address. If the X9418 is still busy with the write operation no ACK will be returned. If the X9418 has completed the write operation an ACK will be returned, and the master can then proceed with the next operation. point to one of the two pots and when applicable they point to one of four associated registers. The format is shown below in Figure 2. Flow 1. ACK Polling Sequence The four high order bits define the instruction. The next two bits (R1 and R0) select one of the four registers that is to be acted upon when a register oriented instruction is issued. The last bits (P0) select which one of the two potentiometers is to be affected by the instruction. Bit 1 is defined to be 0. Nonvolatile Write Command Completed Enter ACK Polling ACK Returned? Issue STOP NO YES Further Operation? NO YES Issue Instruction Issue STOP Proceed Proceed Instruction Structure The next byte sent to the X9418 contains the instruction and register pointer information. The four most significant bits are the instruction. The next four bits REV 1.1.5 7/23/02 Register Select I3 I2 I1 Instructions I0 R1 R0 0 P0 Wiper Counter Register Select Four of the nine instructions end with the transmission of the instruction byte. The basic sequence is illustrated in Figure 3. These two-byte instructions exchange data between the wiper counter register and one of the data registers. A transfer from a Data Register to a Wiper Counter Register is essentially a write to a static RAM. The response of the wiper to this action will be delayed tWRL. A transfer from the wiper counter register (current wiper position), to a Data Register is a write to nonvolatile memory and takes a minimum of tWR to complete. The transfer can occur between one of the two potentiometers and one of its associated registers; or it may occur globally, wherein the transfer occurs between both of the potentiometers and one of their associated registers. Issue START Issue Slave Address Figure 2. Instruction Byte Format Four instructions require a three-byte sequence to complete. These instructions transfer data between the host and the X9418; either between the host and one of the Data Registers or directly between the host and the wiper counter register. These instructions are: Read Wiper Counter Register (read the current wiper position of the selected pot), write Wiper Counter Register (change current wiper position of the selected pot), read Data Register (read the contents of the selected nonvolatile register) and write Data Register (write a new value to the selected Data Register). The sequence of operations is shown in Figure 4. www.xicor.com Characteristics subject to change without notice. 4 of 21 X9418 Figure 3. Two-Byte Instruction Sequence SCL SDA S T A R T 0 1 0 1 A3 A2 A1 A0 A C K The Increment/Decrement command is different from the other commands. Once the command is issued and the X9418 has responded with an acknowledge, the master can clock the selected wiper up and/or down in one segment steps; thereby, providing a fine tuning capability to the host. For each SCL clock pulse (tHIGH) while SDA is HIGH, the selected wiper will move one I3 I2 I1 I0 R1 R0 0 P0 A C K S T O P resistor segment towards the VH/RH terminal. Similarly, for each SCL clock pulse while SDA is LOW, the selected wiper will move one resistor segment towards the VL/RL terminal. A detailed illustration of the sequence and timing for this operation are shown in Figures 5 and 6 respectively. Table 1. Instruction Set I3 I2 Instruction Set I1 I0 R1 R0 1 0 0 1 0 0 0 1 0 1 0 0 0 0 1 0 1 1 1/0 1/0 0 Write Data Register 1 1 0 0 1/0 1/0 0 XFR Data Register to Wiper Counter Register 1 1 0 1 1/0 1/0 0 XFR Wiper Counter Register to Data Register 1 1 1 0 1/0 1/0 0 Global XFR Data Registers to Wiper Counter Registers Global XFR Wiper Counter Registers to Data Register Increment/Decrement Wiper Counter Register 0 0 0 1 1/0 1/0 0 1 0 0 0 1/0 1/0 0 0 0 1 0 Instruction Read Wiper Counter Register Write Wiper Counter Register Read Data Register Note: 0 0 P1 0 P0 Operation 1/0 Read the contents of the Wiper Counter Register pointed to by P0 1/0 Write new value to the Wiper Counter Register pointed to by P0 1/0 Read the contents of the Data Register pointed to by P0 and R1-R0 1/0 Write new value to the Data Register pointed to by P0 and R1-R0 1/0 Transfer the contents of the Data Register pointed to by P0 and R1-R0 to its associated Wiper Counter Register 1/0 Transfer the contents of the Wiper Counter Register pointed to by P0 to the Data Register pointed to by R1-R0 0 Transfer the contents of the Data Registers pointed to by R1-R0 of both pots to their respective Wiper Counter Registers 0 Transfer the contents of both Wiper Counter Registers to their respective data Registers pointed to by R1-R0 of both pots 1/0 Enable Increment/decrement of the Wiper Counter Register pointed to by P0 (7) 1/0 = data is one or zero REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 5 of 21 X9418 Figure 4. Three-Byte Instruction Sequence SCL SDA S T A R T 0 1 0 1 A3 A2 A1 A0 A C K I3 I2 I1 I0 R1 R0 0 P0 A C K 0 0 D5 D4 D3 D2 D1 D0 A C K S T O P Figure 5. Increment/Decrement Instruction Sequence SCL SDA X S T A R T 0 1 0 1 A3 A2 A1 A0 A C K I3 I2 I1 I0 X R1 R0 0 P0 A C K I N C 1 I N C 2 I N C n D E C 1 D E C n S T O P Figure 6. Increment/Decrement Timing Limits INC/DEC CMD Issued tWRID SCL SDA VW/RW REV 1.1.5 7/23/02 Voltage Out www.xicor.com Characteristics subject to change without notice. 6 of 21 X9418 Figure 7. Acknowledge Response from Receiver SCL from Master 1 8 9 Data Output from Transmitter Data Output from Receiver START Acknowledge Figure 8. Detailed Potentiometer Block Diagram Serial Data Path Serial Bus Input From Interface Circuitry Register 0 If WCR = 00[H] then VW/RW = VL/RL If WCR = 3F[H] then VW/RW = VH/RH C o u n t e r Register 1 8 Register 2 VH/RH 6 Parallel Bus Input Wiper Counter Register (WCR) Register 3 D e c o d e INC/DEC Logic UP/DN Modified SCL UP/DN VL/RL CLK VW/RW REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 7 of 21 X9418 DETAILED OPERATION Register Descriptions Both XDCP potentiometers share the serial interface and share a common architecture. Each potentiometer has a Wiper Counter Register and four Data Registers. A detailed discussion of the register organization and array operation follows. Wiper Counter Register The X9418 contains two wiper counter registers, one for each XDCP potentiometer. The Wiper Counter Register can be envisioned as a 6-bit parallel and serial load counter with its outputs decoded to select one of sixty-four switches along its resistor array. The contents of the WCR can be altered in four ways: it may be written directly by the host via the write Wiper Counter Register instruction (serial load); it may be written indirectly by transferring the contents of one of four associated Data Registers via the XFR Data Register instruction (parallel load); it can be modified one step at a time by the Increment/Decrement instruction. Finally, it is loaded with the contents of its Data Register zero (DR0) upon power-up. The WCR is a volatile register; that is, its contents are lost when the X9418 is powered-down. Although the register is automatically loaded with the value in DR0 upon power-up, it should be noted this may be different from the value present at power-down. Data Registers Each potentiometer has four nonvolatile Data Registers. These can be read or written directly by the host and data can be transferred between any of the four Data Registers and the Wiper Counter Register. It should be noted all operations changing data in one of these registers is a nonvolatile operation and will take a maximum of 10ms. Data Registers, (6-Bit), Nonvolatile D5 D4 D3 D2 D1 D0 NV NV NV NV NV NV (MSB) (LSB) Four 6-bit Data Registers for each XDCP. (eight 6-bit registers in total). - {D5~D0}: These bits are for general purpose not volatile data storage or for storage of up to four different wiper values. The contents of Data Register 0 are automatically moved to the Wiper Counter Register on power-up. Wiper Counter Register, (6-Bit), Volatile WP5 WP4 WP3 WP2 WP1 WP0 V V V V V V (MSB) (LSB) One 6-bit wiper counter register for each XDCP. (Four 6-bit registers in total.) - {D5~D0}: These bits specify the wiper position of the respective XDCP. The Wiper Counter Register is loaded on power-up by the value in Data Register 0. The contents of the WCR can be loaded from any of the other Data Register or directly. The contents of the WCR can be saved in a DR. If the application does not require storage of multiple settings for the potentiometer, these registers can be used as regular memory locations that could possibly store system parameters or user preference data. REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 8 of 21 X9418 Instruction Format Notes: (1) (2) (3) (4) (5) "MACK"/"SACK": stands for the acknowledge sent by the master/slave. "A3 ~ A0": stands for the device addresses sent by the master. "X": indicates that it is a "0" for testing purpose but physically it is a "don't care" condition. "I": stands for the increment operation, SDA held high during active SCL phase (high). "D": stands for the decrement operation, SDA held low during active SCL phase (high). Read Wiper Counter Register (WCR) S device type device T identifier addresses A R 0 1 0 1 A A A A 3 2 1 0 T instruction WCR S opcode addresses A C P K 1 0 0 1 0 0 0 0 wiper position S (sent by slave on SDA) A W W W W W W C 0 0 P P P P P P K 5 4 3 2 1 0 M A C K S T O P wiper position S (sent by master on SDA) A W W W W W W C 0 0 P P P P P P K 5 4 3 2 1 0 S A C K S T O P Write Wiper Counter Register (WCR) S device type device T identifier addresses A R 0 1 0 1 A A A A 3 2 1 0 T instruction WCR S opcode addresses A C P K 1 0 1 0 0 0 0 0 Read Data Register (DR) S device type device T identifier addresses A R 0 1 0 1 A A A A 3 2 1 0 T instruction DR and WCR S opcode addresses A C R R P K 1 0 1 1 1 0 0 0 wiper position/data S (sent by slave on SDA) A W W W W W W C 0 0 P P P P P P K 5 4 3 2 1 0 M A C K S T O P Write Data Register (DR) S device type device instruction S T identifier addresses opcode A A C R 0 1 0 1 A A A A 1 1 0 0 3 2 1 0 K T DR and WCR addresses R 1 R 0 wiper position/data S (sent by master on SDA) A W W W W W W C 0 P0 0 0 P P P P P P K 5 4 3 2 1 0 S A C K S T HIGH-VOLTAGE O WRITE CYCLE P XFR Data Register (DR) to Wiper Counter Register (WCR) S device type device instruction DR and WCR S T identifier addresses opcode addresses A A C R R P R 0 1 0 1 A A A A 1 1 0 1 0 3 2 1 0 K 1 0 0 T REV 1.1.5 7/23/02 S A C K S T O P www.xicor.com Characteristics subject to change without notice. 9 of 21 X9418 XFR Wiper Counter Register (WCR) to Data Register (DR) S device type device T identifier addresses A R 0 1 0 1 A A A A 3 2 1 0 T instruction DR and WCR S opcode addresses A C R R P K 1 1 1 0 1 0 0 0 S A C K S T O P HIGH-VOLTAGE WRITE CYCLE Increment/Decrement Wiper Counter Register (WCR) S device type device T identifier addresses A R 0 1 0 1 A A A A 3 2 1 0 T instruction WCR S opcode addresses A C P K 0 0 1 0 0 0 0 0 increment/decrement S (sent by master on SDA) A C I/ I/ I/ I/ K D D . . . . D D S T O P Global XFR Data Register (DR) to Wiper Counter Register (WCR) device S device type identifier addresses T A R 0 1 0 1 A A A A 3 2 1 0 T instruction DR S opcode addresses A C R R K 0 0 0 1 1 0 0 0 S A C K S T O P Global XFR Wiper Counter Register (WCR) to Data Register (DR) S device type device T identifier addresses A R 0 1 0 1 A A A A 3 2 1 0 T instruction DR S opcode addresses A C R R 1 0 0 0 0 0 K 1 0 SYMBOL TABLE REV 1.1.5 7/23/02 S T O P HIGH-VOLTAGE WRITE CYCLE Guidelines for Calculating Typical Values of Bus Pull-Up Resistors INPUTS OUTPUTS 120 Must be steady Will be steady 100 May change from Low to High Will change from Low to High May change from High to Low Will change from High to Low Don't Care: Changes Allowed N/A Changing: State Not Known Center Line is High Impedance Resistance (K) WAVEFORM S A C K 80 60 V RMIN = CC MAX =1.8K IOL MIN RMAX = tR CBUS Max. Resistance 40 20 Min. Resistance 0 0 20 40 60 80 100 120 Bus Capacitance (pF) www.xicor.com Characteristics subject to change without notice. 10 of 21 X9418 ABSOLUTE MAXIMUM RATINGS COMMENT Temperature under bias ....................-65C to +135C Storage temperature .........................-65C to +150C Voltage on SDA, SCL or any address input with respect to VSS ......................... -1V to +7V Voltage on V+ (referenced to VSS) ........................ 10V Voltage on V- (referenced to VSS) ........................ -10V (V+) - (V-) ............................................................. 12V Any VH/RH, VL/RL, VW/RW ............................. V- to V+ Lead temperature (soldering, 10 seconds) ........300C IW (10 seconds) ................................................. 6mA 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. RECOMMENDED OPERATING CONDITIONS Temperature Min. Max. Device Supply Voltage (VCC) Limits Commercial 0C +70C X9418 5V 10% Industrial -40C +85C X9418-2.7 2.7V to 5.5V ANALOG CHARACTERISTICS (Over recommended operating conditions unless otherwise stated.) Symbol Parameter Min. -20 IW RW End to end resistance tolerance Power rating Wiper current Wiper resistance V+ Voltage on V+ pin +4.5 +2.7 -5.5 -5.5 V- X9418 X9418-2.7 VVoltage on V- pin X9418 X9418-2.7 VTERM Voltage on any VH/RH, VL/RL or VW/RW Noise Resolution (4) Absolute linearity (1) Relative linearity (2) Temperature Coefficient of RTOTAL Ratiometric Temperature Coefficient CH/CL/CW Potentiometer Capacitances IAL RH, RL, RW Leakage Current REV 1.1.5 7/23/02 Limits Typ. Max. -3 150 40 +20 50 +3 250 100 +5.5 +5.5 -4.5 -2.7 V+ Unit % mW mA V 25C, each pot Wiper current = 1mA, V+, V- = 3V Wiper current = 1mA, V+, V- = 5V V V -120 1.6 dBV % -1 +1 MI(3) -0.2 +0.2 MI(3) 300 ppm/C 20 ppm/C 10/10/25 pF 0.1 www.xicor.com 10 Test Conditions A Ref: 1kHz See Note 4 Vw(n)(actual)--Vw(n)(expected)(4) Vw(n + 1)--[Vw(n) + MI](4) See Note 4 See Note 4 See Circuit #3, Spice Macromodel VIN = V- to V+. Device is in Stand-by mode. Characteristics subject to change without notice. 11 of 21 X9418 D.C. OPERATING CHARACTERISTICS (Over the recommended operating conditions unless otherwise specified.) Limits Symbol Parameter Min. Typ. Max. Unit Test Conditions 1 mA fSCL = 400kHz, SDA = Open, Other Inputs = VSS 100 A fSCL = 400kHz, SDA = Open, Other Inputs = VSS ICC1 VCC supply current (nonvolatile write) ICC2 VCC supply current (move wiper, write, read) ISB VCC current (standby) 1 A SCL = SDA = VCC, Addr. = VSS ILI Input leakage current 10 A VIN = VSS to VCC ILO Output leakage current 10 A VOUT = VSS to VCC VIH Input HIGH voltage VCC x 0.7 VCC + 0.5 V VIL Input LOW voltage -0.5 VCC x 0.1 V VOL Output LOW voltage 0.4 V IOL = 3mA Notes: (1) Absolute linearity is utilized to determine actual wiper voltage versus expected voltage as determined by wiper position when used as a potentiometer. (2) Relative linearity is utilized to determine the actual change in voltage between two successive tap positions when used as a potentiometer. It is a measure of the error in step size. (3) MI = RTOT/63 or (RH--RL)/63, single pot ENDURANCE AND DATA RETENTION Parameter Min. Unit Minimum endurance 100,000 Data changes per bit per register Data retention 100 Years CAPACITANCE Symbol (4) (4) CI/O CIN Test Max. Unit Test Conditions Input/output capacitance (SDA) 8 pF VI/O = 0V Input capacitance (A0, A1, A2, A3, and SCL) 6 pF VIN = 0V POWER-UP TIMING Symbol (5) (5) tPUR tPUW (6) tRVCC Parameter Min. Max. Unit Power-up to initiation of read operation 1 ms Power-up to initiation of write operation 5 ms 50 V/msec VCC Power up ramp rate 0.2 Typ. Power Up Requirements (Power up sequencing can affect correct recall of the wiper registers) The preferred power-on sequence is as follows: First VCC, then V+ and V-, and then the potentiometer pins, RH, RL, and RW. Voltage should not be applied to the potentiometer pins before V+ or V- is applied. The VCC ramp rate specification should be met, and any glitches or slope changes in the VCC line should be held to <100mV if possible. If VCC powers down, it should be held below 0.1V for more than 1 second before powering up again in order for proper wiper register recall. Also, VCC should not reverse polarity by more than 0.5V. Recall of wiper position will not be complete until VCC, V+ and V- reach their final value. Notes: (4) This parameter is periodically sampled and not 100% tested (5) tPUR and tPUW are the delays required from the time the third (last) power supply (VCC, V+ or V-) is stable until the specific instruction can be issued. These parameters are periodically sampled and not 100% tested. (6) This is a tested or guaranteed parameter and should only be used as a guidance. REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 12 of 21 X9418 A.C. TEST CONDITIONS Circuit #3 SPICE Macro Model Input pulse levels VCC x 0.1 to VCC x 0.9 Input rise and fall times 10ns Input and output timing level VCC x 0.5 RTOTAL RH CL CH CW RL 10pF EQUIVALENT A.C. LOAD CIRCUIT 10pF 5V 25pF RW 1533 SDA Output 100pF AC TIMING (over recommended operating conditions) Symbol Parameter Min. Max. Unit 400 kHz fSCL Clock frequency tCYC Clock cycle time 2500 ns tHIGH Clock high time 600 ns tLOW Clock low time 1300 ns tSU:STA Start setup time 600 ns tHD:STA Start hold time 600 ns tSU:STO Stop setup time 600 ns tSU:DAT SDA data input setup time 100 ns tHD:DAT SDA data input hold time 30 ns tR SCL and SDA rise time 300 ns tF SCL and SDA fall time 300 ns 900 ns tAA SCL low to SDA data output valid time tDH SDA data output hold time 50 ns Noise suppression time constant at SCL and SDA inputs 50 ns 1300 ns TI tBUF Bus free time (prior to any transmission) tSU:WPA WP, A0, A1, A2 and A3 setup time 0 ns tHD:WPA WP, A0, A1, A2 and A3 hold time 0 ns REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 13 of 21 X9418 HIGH-VOLTAGE WRITE CYCLE TIMING Symbol Parameter tWR Typ. Max. Unit 5 10 ms High-voltage write cycle time (store instructions) XDCP TIMING Symbol tWRPO Parameter Min. Max. Unit 10 s Wiper response time after the third (last) power supply is stable tWRL Wiper response time after instruction issued (all load instructions) 10 s tWRID Wiper response time from an active SCL/SCK edge (increment/decrement instruction) 10 s Note: (8) A device must internally provide a hold time of at least 300ns for the SDA signal in order to bridge the undefined region of the falling edge of SCL. TIMING DIAGRAMS START and STOP Timing g (START) (STOP) tF tR SCL tSU:STA tHD:STA tSU:STO tR tF SDA Input Timing tCYC tHIGH SCL tLOW SDA tSU:DAT tHD:DAT tBUF Output Timing SCL SDA tDH tAA REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 14 of 21 X9418 XDCP Timing (for All Load Instructions) (STOP) SCL LSB SDA tWRL VW/RW XDCP Timing (for Increment/Decrement Instruction) SCL SDA Wiper Register Address Inc/Dec Inc/Dec tWRID VW/RW Write Protect and Device Address Pins Timing (START) (STOP) SCL ... (Any Instruction) ... SDA ... tSU:WPA tHD:WPA WP A0, A1 A2, A3 REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 15 of 21 X9418 APPLICATIONS INFORMATION Basic Configurations of Electronic Potentiometers +VR VR VW/RW I Three terminal Potentiometer; Variable voltage divider Two terminal Variable Resistor; Variable current Application Circuits Noninverting Amplifier VS Voltage Regulator + VO - VIN VO (REG) 317 R1 R2 Iadj R1 R2 VO = (1+R2/R1)VS VO (REG) = 1.25V (1+R2/R1)+Iadj R2 Offset Voltage Adjustment R1 Comparator with Hysteresis R2 VS VS - + VO 100K - VO + } } TL072 R1 R2 10K 10K +12V REV 1.1.5 7/23/02 10K VUL = {R1/(R1+R2)} VO(max) VLL = {R1/(R1+R2)} VO(min) -12V www.xicor.com Characteristics subject to change without notice. 16 of 21 X9418 Application Circuits (continued) Attenuator Filter C VS + R2 R1 VS VO - - R VO + R3 R4 R2 All RS = 10k R1 GO = 1 + R2/R1 fc = 1/(2pRC) VO = G VS -1/2 G +1/2 R1 R2 } } Inverting Amplifier Equivalent L-R Circuit VS R2 C1 - VS VO + + - R1 ZIN VO = G VS G = - R2/R1 R3 ZIN = R2 + s R2 (R1 + R3) C1 = R2 + s Leq (R1 + R3) >> R2 Function Generator C R2 - + R1 - } RA + } RB frequency R1, R2, C amplitude RA, RB REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 17 of 21 X9418 PACKAGING INFORMATION 24-Lead Plastic Dual In-Line Package Type P 1.265 (32.13) 1.230 (31.24) 0.557 (14.15) 0.530 (13.46) Pin 1 Index Pin 1 0.080 (2.03) 0.065 (1.65) 1.100 (27.94) Ref. 0.162 (4.11) 0.140 (3.56) Seating Plane 0.030 (0.76) 0.015 (0.38) 0.150 (3.81) 0.125 (3.18) 0.110 (2.79) 0.090 (2.29) 0.065 (1.65) 0.040 (1.02) 0.022 (0.56) 0.014 (0.36) 0.625 (15.87) 0.600 (15.24) 0 15 Typ. 0.010 (0.25) NOTE: 1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 2. PACKAGE DIMENSIONS EXCLUDE MOLDING FLASH REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 18 of 21 X9418 PACKAGING INFORMATION 24-Lead Plastic Small Outline Gull Wing Package Type S 0.290 (7.37) 0.393 (10.00) 0.299 (7.60) 0.420 (10.65) Pin 1 Index Pin 1 0.014 (0.35) 0.020 (0.50) 0.598 (15.20) 0.610 (15.49) (4X) 7 0.092 (2.35) 0.105 (2.65) 0.003 (0.10) 0.012 (0.30) 0.050 (1.27) 0.050" Typical 0.010 (0.25) X 45 0.020 (0.50) 0.050" Typical 0 - 8 0.009 (0.22) 0.013 (0.33) 0.420" 0.015 (0.40) 0.050 (1.27) FOOTPRINT 0.030" Typical 24 Places NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 19 of 21 X9418 PACKAGING INFORMATION 24-Lead Plastic, TSSOP Package Type V .026 (.65) BSC .169 (4.3) .252 (6.4) BSC .177 (4.5) .303 (7.70) .311 (7.90) .047 (1.20) .0075 (.19) .0118 (.30) .002 (.06) .005 (.15) .010 (.25) Gage Plane 0-8 (4.16) (7.72) Seating Plane .020 (.50) .030 (.75) (1.78) Detail A (20X) (0.42) (0.65) .031 (.80) .041 (1.05) ALL MEASUREMENTS ARE TYPICAL See Detail "A" NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 20 of 21 X9418 Ordering Information X9418 Y P T V VCC Limits Blank = 5V 10% -2.7 = 2.7 to 5.5V Device Temperature Range Blank = Commercial = 0C to +70C I = Industrial = -40C to +85C Package P24 = 24-Lead Plastic DIP S24 = 24-Lead SOIC V24 = 24-Lead TSSOP Potentiometer Organization Pot 0 Pot 1 W= 10K 10K Y= 2.5K 2.5K LIMITED WARRANTY (c)Xicor, Inc. 2000 Patents Pending Devices sold by Xicor, Inc. are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. Xicor, Inc. makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Xicor, Inc. makes no warranty of merchantability or fitness for any purpose. Xicor, Inc. reserves the right to discontinue production and change specifications and prices at any time and without notice. Xicor, Inc. assumes no responsibility for the use of any circuitry other than circuitry embodied in a Xicor, Inc. product. No other circuits, patents, or licenses are implied. TRADEMARK DISCLAIMER: Xicor and the Xicor logo are registered trademarks of Xicor, Inc. AutoStore, Direct Write, Block Lock, SerialFlash, MPS, and XDCP are also trademarks of Xicor, Inc. All others belong to their respective owners. U.S. PATENTS Xicor products are covered by one or more of the following U.S. Patents: 4,326,134; 4,393,481; 4,404,475; 4,450,402; 4,486,769; 4,488,060; 4,520,461; 4,533,846; 4,599,706; 4,617,652; 4,668,932; 4,752,912; 4,829,482; 4,874,967; 4,883,976; 4,980,859; 5,012,132; 5,003,197; 5,023,694; 5,084,667; 5,153,880; 5,153,691; 5,161,137; 5,219,774; 5,270,927; 5,324,676; 5,434,396; 5,544,103; 5,587,573; 5,835,409; 5,977,585. Foreign patents and additional patents pending. LIFE RELATED POLICY In situations where semiconductor component failure may endanger life, system designers using this product should design the system with appropriate error detection and correction, redundancy and back-up features to prevent such an occurrence. Xicor's products are not authorized for use in critical components in life support devices or systems. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. REV 1.1.5 7/23/02 www.xicor.com Characteristics subject to change without notice. 21 of 21