APPLICATION NOTES AND DEVELOPMENT SYSTEM A V A I L A B L E AN99 * AN115 * AN124 *AN133 * AN134 * AN135 Single Supply / Low Power / 256-tap / SPI bus X9271 Single Digitally-Controlled (XDCPTM) Potentiometer FEATURES DESCRIPTION * 256 Resistor Taps * SPI Serial Interface for write, read, and transfer operations of the potentiometer * Wiper Resistance, 100 typical @ VCC = 5V * 16 Nonvolatile Data Registers * Nonvolatile Storage of Multiple Wiper Positions * Power On Recall. Loads Saved Wiper Position on Power Up. * Standby Current < 3A Max * VCC: 2.7V to 5.5V Operation * 50K, 100K versions of End to End Resistance * 100 yr. Data Retention * Endurance: 100,000 Data Changes per Bit per Register * 14-Lead TSSOP, xx-Lead XBGA * Low Power CMOS The X9271 integrates a single digitally controlled potentiometer (XDCP) on a monolithic CMOS integrated circuit. The digital controlled potentiometer is implemented using 255 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 SPI bus interface. The potentiometer has associated with it a volatile Wiper Counter Register (WCR) and a four nonvolatile Data Registers 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 though the switches. Powerup recalls the contents of the default data register (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. FUNCTIONAL DIAGRAM VCC SPI Bus Interface Address Data Status RH Write Read Transfer Inc/Dec Wiper Counter Register (WCR) Bus Interface and Control Control POT Data Registers 16 Bytes RW VSS REV 1.1.2 12/8/00 50K and 100K 256-taps Power On Recall www.xicor.com RL Characteristics subject to change without notice. 1 of 23 X9271 DETAILED FUNCTIONAL DIAGRAM VCC Bank 0 Power On Recall R0 R1 HOLD CS SCK SO SI A0 A1 R2 R3 INTERFACE AND CONTROL CIRCUITRY 50K and 100K 256-taps WIPER COUNTER REGISTER (WCR) RH RL RW DATA WP Bank 1 Bank 2 Bank 3 R0 R1 R0 R1 R0 R1 R2 R3 R2 R3 R2 R3 Control 12 additional nonvolatile registers 3 Banks of 4 registers x 8-bits VSS CIRCUIT LEVEL APPLICATIONS SYSTEM LEVEL APPLICATIONS * Vary the gain of a voltage amplifier * Adjust the contrast in LCD displays * Provide programmable dc reference voltages for comparators and detectors * Control the power level of LED transmitters in communication systems * Control the volume in audio circuits * Set and regulate the DC biasing point in an RF power amplifier in wireless systems * Trim out the offset voltage error in a voltage amplifier circuit * Set the output voltage of a voltage regulator * Trim the resistance in Wheatstone bridge circuits * Control the gain, characteristic frequency and Q-factor in filter circuits * Set the scale factor and zero point in sensor signal conditioning circuits * Vary the frequency and duty cycle of timer ICs * Vary the dc biasing of a pin diode attenuator in RF circuits * Control the gain in audio and home entertainment systems * Provide the variable DC bias for tuners in RF wireless systems * Set the operating points in temperature control systems * Control the operating point for sensors in industrial systems * Trim offset and gain errors in artificial intelligent systems * Provide a control variable (I, V, or R) in feedback circuits REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 2 of 23 X9271 PIN CONFIGURATION XBGA TSSOP X9271 S0 1 A0 2 NC 3 12 RH CS SCK 4 11 RW 5 10 HOLD SI 6 VSS 7 9 8 WP X9271 14 VCC 13 RL A1 PIN ASSIGNMENTS Pin (TSSOP) Pin (XBGA) Symbol Function 1 SO Serial Data Output. 2 A0 Device Address. 3 NC No Connect. 4 CS Chip Select. 5 SCK Serial Clock. 6 SI Serial Data Input. 7 VSS System Ground. 8 WP Hardware Write Protect. 9 A1 Device Address. 10 HOLD Device select. Pause the serial bus. 11 RW Wiper Terminal of the Potentiometer. 12 RH High Terminal of the Potentiometer. 13 RL Low Terminal of the Potentiometer. 14 VCC REV 1.1.2 12/8/00 System Supply Voltage. www.xicor.com Characteristics subject to change without notice. 3 of 23 X9271 PIN DESCRIPTIONS Potentiometer Pins Bus Interface Pins RH, RL SERIAL OUTPUT (SO) The RH and RL pins are equivalent to the terminal connections on a mechanical potentiometer. SO is a serial data output pin. During a read cycle, data is shifted out on this pin. Data is clocked out by the falling edge of the serial clock. RW SERIAL INPUT SI is the serial data input pin. All opcodes, byte addresses and data to be written to the pots and pot registers are input on this pin. Data is latched by the rising edge of the serial clock. SERIAL CLOCK (SCK) The SCK input is used to clock data into and out of the X9271. The wiper pin are equivalent to the wiper terminal of a mechanical potentiometer. Supply Pins SYSTEM SUPPLY VOLTAGE (VCC) AND SUPPLY GROUND (VSS) The VCC pin is the system supply voltage. The VSS pin is the system ground. Other Pins HARDWARE WRITE PROTECT INPUT (WP) HOLD (HOLD) HOLD is used in conjunction with the CS pin to select the device. Once the part is selected and a serial sequence is underway, HOLD may be used to pause the serial communication with the controller without resetting the serial sequence. To pause, HOLD must be brought LOW while SCK is LOW. To resume communication, HOLD is brought HIGH, again while SCK is LOW. If the pause feature is not used, HOLD should be held HIGH at all times. CMOS level input. The WP pin when LOW prevents nonvolatile writes to the Data Registers. NO CONNECT. No connect pins should be left floating. This pins are used for Xicor manufacturing and testing purposes. DEVICE ADDRESS (A1 - A0) The address inputs are used to set the 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 X9271. CHIP SELECT (CS) When CS is HIGH, the X9271 is deselected and the SO pin is at high impedance, and (unless an internal write cycle is underway) the device will be in the standby state. CS LOW enables the X9271, placing it in the active power mode. It should be noted that after a power-up, a HIGH to LOW transition on CS is required prior to the start of any operation. REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 4 of 23 X9271 physical ends of each array are equivalent to the fixed terminals of a mechanical potentiometer (RH and RL inputs). PRINCIPLES OF OPERATION Device Description At both ends of each array and between each resistor segment is a CMOS switch connected to the wiper (RW) output. Within each individual array only one switch may be turned on at a time. SERIAL INTERFACE The X9271 supports the SPI interface hardware conventions. The device is accessed via the SI input with data clocked in on the rising SCK. CS must be LOW and the HOLD and WP pins must be HIGH during the entire operation. These switches are controlled by a Wiper Counter Register (WCR). The 8-bits of the WCR (WCR[7:0]) are decoded to select, and enable, one of 256 switches (see Table 1). The SO and SI pins can be connected together, since they have three state outputs. This can help to reduce system pin count. POWER UP AND DOWN RECOMMENDATIONS. There are no restrictions on the power-up or powerdown conditions of VCC and the voltages applied to the potentiometer pins provided that VCC is always more positive than or equal to VH, VL, and VW, i.e., VCC VH, VL, VW. The VCC ramp rate specification is always in effect. ARRAY DESCRIPTION The X9271 is comprised of a resistor array (see Figure 1). The array contains the equivalent of 255 discrete resistive segments that are connected in series. The Figure 1. Detailed Potentiometer Block Diagram SERIAL DATA PATH RH SERIAL BUS INPUT FROM INTERFACE CIRCUITRY REGISTER 0 (DR0) 8 8 BANK_0 Only REGISTER 2 (DR2) IF WCR = 00[H] THEN RW = RL IF WCR = FF[H] THEN RW = RH C O U N T E R REGISTER 1 (DR1) REGISTER 3 (DR3) PARALLEL BUS INPUT WIPER COUNTER REGISTER (WCR) D E C O D E INC/DEC LOGIC UP/DN MODIFIED SCK UP/DN CLK RL RW REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 5 of 23 X9271 DEVICE DESCRIPTION Wiper Counter Register (WCR) The X9271 contains a Wiper Counter Register for the DCP potentiometer. The Wiper Counter Register can be envisioned as a 8-bit parallel and serial load counter with its outputs decoded to select one of 256 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 Wiper Counter Register is a volatile register; that is, its contents are lost when the X9271 is powereddown. Although the register is automatically loaded with the value in DR0 upon power-up, this may be different from the value present at power-down. Powerup guidelines are recommended to ensure proper loadings of the R0 value into the WCR. The DR0 value of Bank 0 is the default value. Data Registers (DR3-DR0) The potentiometer has four 8-bit nonvolatile Data Registers. These can be read or written directly by the host. Data can also be transferred between any of the four Data Registers and the associated Wiper Counter Register. All operations changing data in one of the Data Registers is a nonvolatile operation and will take a maximum of 10ms. If the application does not require storage of multiple settings for the potentiometer, the Data Registers can be used as regular memory locations for system parameters or user preference data. Bits [7:0] are used to store one of the 256 wiper positions or data (0 ~255). Status Register (SR) This 1-bit Status Register is used to store the system status. WIP: Write In Progress status bit, read only. - When WIP=1, indicates that high-voltage write cycle is in progress. - When WIP=0, indicates that no high-voltage write cycle is in progress Table 1. Wiper counter Register, WCR (8-bit), WCR[7:0]: Used to store the current wiper position (Volatile, V). WCR7 WCR6 WCR5 WCR4 WCR3 WCR2 WCR1 WCR0 V V V V V V V V (MSB) (LSB) Table 2. Data Register, DR (8-bit), DR[7:0]: Used to store wiper positions or data (Nonvolatile, NV). Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 NV NV NV NV NV NV NV NV MSB LSB Table 3. Status Register, SR (WIP is 1-bit) WIP (LSB) REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 6 of 23 X9271 Banks 1, 2, and 3 are additional banks of registers (12 total) that can be used for SPI write and read operations. The data registers in Banks 1, 2, and 3 cannot be used for direct read/write operations between the Wiper Counter Register. DEVICE DESCRIPTION Instructions IDENTIFICATION BYTE (ID AND A) The first byte sent to the X9271 from the host, following a CS going HIGH to LOW, is called the Identification byte. The most significant four bits of the slave address are a device type identifier. The ID[3:0] bits is the device id for the X9271; this is fixed as 0101[B] (refer to Table 4). The A1-A0 bits in the ID byte is the internal slave address. The physical device address is defined by the state of the A1-A0 input pins. The slave address is externally specified by the user. The X9271 compares the serial data stream with the address input state; a successful compare of both address bits is required for the X9271 to successfully continue the command sequence. Only the device which slave address matches the incoming device address sent by the master executes the instruction. The A1-A0 inputs can be actively driven by CMOS input signals or tied to VCC or VSS. Register Selection (DR0 to DR3) Table Register RB RA Selection 0 0 0 0 1 1 1 0 2 1 1 3 The next byte sent to the X9271 contains the instruction and register pointer information. The three most significant bits are used provide the instruction opcode (I[3:0]). The RB and RA bits point to one of the four Data Registers. P0 is the POT selection; since the X9271 is single POT, the P0=0. The format is shown in Table 5. Data Register Read and Write; Wiper Counter Register Operations Data Register Read and Write; Wiper Counter Register Operations Data Register Read and Write; Wiper Counter Register Operations Data Register Read and Write; Wiper Counter Register Operations Register Bank Selection (Bank 0 to Bank 3) Table P1 INSTRUCTION BYTE (I[3:0]) Operations Bank P0 Selection 0 0 0 0 1 1 1 0 2 1 1 3 Operations Data Register Read and Write; Wiper Counter Register Operations Data Register Read and Write Only Data Register Read and Write Only Data Register Read and Write Only REGISTER BANK SELECTION (R1, R0, P1, P0) There are 16 registers organized into four banks. Bank 0 is the default bank of registers. Only Bank 0 registers can be used for data register to Wiper Counter Register operations. Table 4. Identification Byte Format Device Type Identifier Set to 0 for proper operation ID3 ID2 ID1 ID0 0 1 0 1 0 0 (MSB) REV 1.1.2 12/8/00 Internal Slave Address A1 A0 (LSB) www.xicor.com Characteristics subject to change without notice. 7 of 23 X9271 Table 5. Instruction Byte Format P1 and P0 are used also for register Bank Selection for SPI Register Write and Read operations Instruction Opcode I3 I2 I1 P0 RB RA (MSB) P1 P0 (LSB) DEVICE DESCRIPTION Instructions Five of the eight instructions are three bytes in length. These instructions are: - Read Wiper Counter Register - read the current wiper position of the potentiometer; - Write Wiper Counter Register - change current wiper position of the potentiometer; - Read Data Register - read the contents of the selected Data Register; - Write Data Register - write a new value to the selected Data Register. - Read Status - This command returns the contents of the WIP bit which indicates if the internal write cycle is in progress. The basic sequence of the three byte instructions is illustrated in Figure 3. These three-byte instructions exchange data between the WCR and one of the Data Registers. A transfer from a Data Register to a WCR is essentially a write to a static RAM, with the static RAM controlling the wiper position. The response of the wiper to this action will be delayed by tWRL. A transfer from the WCR (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 four potentiometers and one of its associated registers; or it may occur globally, where the transfer occurs between all potentiometers and one associated register. The Read Status Register instruction is the only unique format (see Figure 4). REV 1.1.2 12/8/00 Pot Selection (WCR Selection) Set to P0=0 for potentiometer operations Register Selection Two instructions require a two-byte sequence to complete (Figure 2). These instructions transfer data between the host and the X9271; either between the host and one of the data registers or directly between the host and the Wiper Counter Register. These instructions are: - XFR Data Register to Wiper Counter Register - This transfers the contents of one specified Data Register to the associated Wiper Counter Register. - XFR Wiper Counter Register to Data Register - This transfers the contents of the specified Wiper Counter Register to the specified associated Data Register. The final command is Increment/Decrement (Figure 5 and 6). It is different from the other commands, because it's length is indeterminate. Once the command is issued, the master can clock the selected wiper up and/or down in one resistor segment steps; thereby, providing a fine tuning capability to the host. For each SCK clock pulse (tHIGH) while SI is HIGH, the selected wiper will move one resistor segment towards the RH terminal. Similarly, for each SCK clock pulse while SI is LOW, the selected wiper will move one resistor segment towards the RL terminal. See Instruction format for more details. Write in Process (WIP bit) The contents of the Data Registers are saved to nonvolatile memory when the CS pin goes from LOW to HIGH after a complete write sequence is received by the device. The progress of this internal write operation can be monitored by a Write In Process bit (WIP). The WIP bit is read with a Read Status command. www.xicor.com Characteristics subject to change without notice. 8 of 23 X9271 Figure 2. Two-Byte Instruction Sequence CS SCK SI 1 0 0 ID3 ID2 ID1 ID0 0 0 0 1 0 0 A1 A0 I3 Internal Address Device ID I2 I1 I0 RB RA P1 P0 Register Address Instruction Opcode 0 Pot/Bank Address These commands only valid when P1=P0=0 Figure 3. Three-Byte Instruction Sequence (Write) CS SCL SI 0 1 0 1 ID3 ID2 ID1 ID0 0 0 0 0 A1 A0 Internal Address Device ID I3 I2 I1 I0 Instruction Opcode RB RA P1 P0 Register Address D7 D6 D5 D4 D3 D2 D1 D0 Pot/Bank WCR[7:0] valid only when P1=P0=0; Address or Data Register Bit [7:0] for all values of P1 and P0 Figure 4. Three-Byte Instruction Sequence (Read) CS SCL SI 0 1 0 1 ID3 ID2 ID1 ID0 Device ID 0 0 0 0 X A1 A0 Internal Address I3 I2 I1 I0 Instruction Opcode RB RA P1 P0 Register Address X X X X X X X Don't Care Pot/Bank Address S0 D7 D6 D5 D4 D3 D2 D1 D0 WCR[7:0] valid only when P1=P0=0; or Data Register Bit [7:0] for all values of P1 and P0 REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 9 of 23 X9271 Figure 5. Increment/Decrement Instruction Sequence CS SCL SI 0 1 0 1 ID3 ID2 ID1 ID0 0 0 0 0 0 A1 A0 I3 Internal Address Device ID I1 I2 I0 Instruction Opcode 0 RA RB P1 P0 Register Address Pot/Bank Address I N C 1 I N C 2 I N C n D E C 1 D E C n Figure 6. Increment/Decrement Timing Limits tWRID SCK SI VOLTAGE OUT VW INC/DEC CMD ISSUED Table 6. Instruction Set Instruction I3 I2 Instruction Set I1 I0 RB RA 1 0 0 1 0 P1 P0 Operation 0 0 1/0 Read the contents of the Wiper Counter Register Write new value to the Wiper Counter Register Read the contents of the Data Register pointed to by P1-P0 and RB-RA Write new value to the Data Register pointed to by P1-P0 and RB-RA Transfer the contents of the Data Register pointed to by RB-RA (Bank 0 only) to the Wiper Counter Register Transfer the contents of the Wiper Counter Register to the Register pointed to by RB-RA (Bank 0 only) Enable Increment/decrement of the Wiper Counter Register Read the status of the internal write cycle, by checking the WIP bit. Read Wiper Counter Register Write Wiper Counter Register Read Data Register 1 0 1 0 0 0 0 1/0 1 0 1 1 1/0 1/0 1/0 1/0 Write Data Register 1 1 0 0 1/0 1/0 1/0 1/0 XFR Data Register to Wiper Counter Register 1 1 0 1 1/0 1/0 0 0 XFR Wiper Counter Register to Data Register 1 1 1 0 1/0 1/0 0 0 Increment/Decrement Wiper Counter Register Read Status (WIP bit) 0 0 1 0 0 0 0 0 0 1 0 1 0 0 0 1 Note: 1/0 = data is one or zero REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 10 of 23 X9271 INSTRUCTION FORMAT Read Wiper Counter Register (WCR) Device Type Identifier CS Falling Edge 0 1 0 1 Device Addresses Instruction Opcode 0 0 A1 A0 1 0 0 DR/Bank Addresses 1 0 0 0 Wiper Position (Sent by X9271 on SO) W C R 6 W C 0 R 7 W C R 5 W C R 4 W C R 3 W C R 2 W C R 1 CS W Rising C Edge R 0 Write Wiper Counter Register (WCR) Device Type Identifier CS Falling Edge 0 1 0 1 Device Addresses Instruction Opcode 0 0 A1 A0 1 0 1 DR/Bank Addresses 0 0 0 0 Data Byte (Sent by Host on SI) W C 0 R 7 W C R 6 W C R 5 W C R 4 W C R 3 W C R 2 W C R 1 CS W Rising C Edge R 0 Read Data Register (DR) Device Type Device Instruction DR/Bank Data Byte CS CS Identifier Addresses Opcode Addresses (Sent by X9271 on SO) Falling Rising Edge 0 1 0 1 0 0 A1 A0 1 0 1 1 RB RA P1 P0 D7 D 6 D5 D4 D3 D2 D1 D0 Edge Device Type Identifier Device Addresses Instruction Opcode DR/Bank Addresses Data Byte (Sent by Host on SI) CS CS Falling Rising Edge 0 1 0 1 0 0 A1 A0 1 1 0 0 RB RA P1 P0 D7 D 6 D5 D4 D3 D2 D1 D0 Edge HIGH-VOLTAGE WRITE CYCLE Write Data Register (DR) Transfer Wiper Counter Register (WCR) to Data Register (DR) Device Type CS Identifier Falling Edge 0 1 0 1 REV 1.1.2 12/8/00 Device Addresses Instruction Opcode 0 0 A1 A0 1 1 1 0 DR/Bank Addresses RB RA 0 www.xicor.com 0 CS Rising Edge HIGH-VOLTAGE WRITE CYCLE Characteristics subject to change without notice. 11 of 23 X9271 Transfer Data Register (DR) to Wiper Counter Register (WCR) Device Type Device CS Identifier Addresses Falling Edge 0 1 0 1 0 0 A1 A0 Instruction Opcode DR/Bank Addresses 1 1 0 1 RB RA 0 0 CS Rising Edge Increment/Decrement Wiper Counter Register (WCR) Device Type CS Identifier Falling Edge 0 1 0 1 Device Addresses 0 0 A1 A0 Instruction Opcode DR/Bank Addresses Increment/Decrement (Sent by Master on SDA) 0 0 1 0 X X 0 0 I/D I/D . . . . CS Rising I/D I/D Edge Read Status Register (SR) Device Type Device CS Identifier Addresses Falling Edge 0 1 0 1 0 0 A1 A0 Notes: (1) (2) (2) (3) (4) Instruction Opcode DR/Bank Addresses Data Byte (Sent by X9271 on SO) 0 1 0 1 0 0 0 1 0 0 0 0 0 0 0 WIP CS Rising Edge "A1 ~ A0": stands for the device addresses sent by the master. WCRx refers to wiper position data in the Wiper Counter Register "I": stands for the increment operation, SI held HIGH during active SCK phase (high). "D": stands for the decrement operation, SI held LOW during active SCK phase (high). "X:": Don't Care. REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 12 of 23 X9271 ABSOLUTE MAXIMUM RATINGS COMMENT Temperature under bias ................... -65C to +135C Storage temperature ........................ -65C to +150C Voltage on SCK any address input with respect to VSS ..................................-1V to +7V V = |(VH-VL)|...................................................... 5.5V 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; the 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 Temp Min. Max. Device Supply Voltage (VCC)(4) Limits Commercial 0C +70C X9271 5V 10% -40C +85C X9271-2.7 2.7V to 5.5V Industrial ANALOG CHARACTERISTICS (Over recommended industrial operating conditions unless otherwise stated.) Limits Symbol Parameter Min. Typ. RTOTAL End to End Resistance 100 RTOTAL End to End Resistance 50 End to End Resistance Tolerance Max. Units Test Conditions k T version k U version 20 % Power Rating 50 mW IW Wiper Current 3 mA RW Wiper Resistance 300 IW = 3mA @ VCC = 3V RW Wiper Resistance 150 IW = 3mA @ VCC = 5V VTERM Voltage on any RH or RL Pin VCC V VSS = 0V Noise Resolution VSS -120 dBV/ Hz 0.4 % Ref: 1V Absolute Linearity(1) 1 MI(3) Rw(n)(actual) - Rw(n)(expected)(5) Relative Linearity(2) 0.2 MI(3) Rw(n + 1) - [Rw(n) + MI](5) Temperature Coefficient of RTOTAL 300 Ratiometric Temp. Coefficient CH/CL/CW 25C, each pot Potentiometer Capacitancies ppm/C 20 10/10/25 ppm/C pF See Macro model 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 / 255 or (RH - RL) / 255, single pot (4) During power up VCC > VH, VL, and VW. (5) n = 0, 1, 2, ...,255; m =0, 1, 2, ...., 254. REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 13 of 23 X9271 D.C. OPERATING CHARACTERISTICS (Over the recommended operating conditions unless otherwise specified.) Limits Symbol Parameter Min. Typ. Max. Units Test Conditions 400 A fSCK = 2.5 MHz, SO = Open, VCC=6V Other Inputs = VSS 5 mA fSCK = 2.5MHz, SO = Open, VCC=6V Other Inputs = VSS ICC1 VCC supply current (active) ICC2 VCC supply current (nonvolatile write) ISB VCC current (standby) 3 A SCK = SI = VSS, Addr. = VSS, CS = VCC = 6V 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 + 1 V VIL Input LOW voltage -1 VCC x 0.3 V VOL Output LOW voltage 0.4 V IOL = 3mA VOH Output HIGH voltage VCC - 0.8 V IOH = -1mA, VCC +3V VOH Output HIGH voltage VCC - 0.4 V IOH = -0.4mA, VCC +3V 1 ENDURANCE AND DATA RETENTION Parameter Min. Units Minimum endurance 100,000 Data changes per bit per register Data retention 100 years CAPACITANCE Symbol (6) CIN/OUT (6) COUT (6) CIN Test Max. Units Test Conditions Input / Output capacitance (SI) 8 pF VOUT = 0V Output capacitance (SO) 8 pF VOUT = 0V Input capacitance (A0, CS, WP, HOLD, and SCK) 6 pF VIN = 0V POWER-UP TIMING Symbol (6) Parameter Min. Max. Units 0.2 tr VCC VCC Power-up rate 50 V/ms tPUR(7) Power-up to initiation of read operation 1 ms (7) Power-up to initiation of write operation 50 ms tPUW A.C. TEST CONDITIONS Input Pulse Levels Input rise and fall times Input and output timing level VCC x 0.1 to VCC x 0.9 10ns VCC x 0.5 Notes: (6) This parameter is not 100% tested (7) tPUR and tPUW are the delays required from the time the (last) power supply (VCC-) is stable until the specific instruction can be issued. These parameters are periodically sampled and not 100% tested. REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 14 of 23 X9271 EQUIVALENT A.C. LOAD CIRCUIT 5V SPICE Macromodel 3V 1462 1382 RTOTAL RH SO pin RL SO pin 2714 100pF CW CL 1217 100pF CL 10pF 25pF 10pF RW AC TIMING Symbol Parameter Min. Max. Units 2.5 MHz fSCK SSI/SPI clock frequency tCYC SSI/SPI clock cycle time 500 ns tWH SSI/SPI clock high time 200 ns tWL SSI/SPI clock low time 200 ns tLEAD Lead time 250 ns tLAG Lag time 250 ns tSU SI, SCK, HOLD and CS input setup time 50 ns tH SI, SCK, HOLD and CS input hold time 50 ns tRI SI, SCK, HOLD and CS input rise time 2 s tFI SI, SCK, HOLD and CS input fall time 2 s tDIS SO output disable time 250 ns tV SO output valid time 200 ns tHO SO output hold time tRO SO output rise time 100 ns tFO SO output fall time 100 ns tHOLD HOLD time 400 ns tHSU HOLD setup time 100 ns tHH HOLD hold time 100 ns tHZ HOLD low to output in high Z 100 ns tLZ HOLD high to output in low Z 100 ns TI Noise suppression time constant at SI, SCK, HOLD and CS inputs tCS CS deselect time 2 s tWPASU WP, A0 setup time 0 ns tWPAH WP, A0 hold time 0 ns REV 1.1.2 12/8/00 0 0 www.xicor.com ns 10 Characteristics subject to change without notice. ns 15 of 23 X9271 HIGH-VOLTAGE WRITE CYCLE TIMING Symbol tWR Parameter High-voltage write cycle time (store instructions) Typ. Max. Units 5 10 ms XDCP TIMING Symbol Parameter Min. Max. Units tWRPO Wiper response time after the third (last) power supply is stable 5 10 s tWRL Wiper response time after instruction issued (all load instructions) 5 10 s SYMBOL TABLE WAVEFORM REV 1.1.2 12/8/00 INPUTS OUTPUTS Must be steady Will be steady 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 Changing: State Not Known N/A Center Line is High Impedance www.xicor.com Characteristics subject to change without notice. 16 of 23 X9271 TIMING DIAGRAMS Input Timing tCS CS SCK tSU tH ... tWH tWL ... MSB SI tLAG tCYC tLEAD tRI tFI LSB High Impedance SO Output Timing CS SCK ... tV tDIS ... MSB SO SI tHO LSB ADDR Hold Timing CS tHSU tHH SCK ... tRO tFO SO tHZ tLZ SI tHOLD HOLD REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 17 of 23 X9271 XDCP Timing (for All Load Instructions) CS SCK ... tWRL ... MSB SI LSB VWx SO High Impedance Write Protect and Device Address Pins Timing (Any Instruction) CS tWPAH tWPASU WP A0 A1 REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 18 of 23 X9271 APPLICATIONS INFORMATION Basic Configurations of Electronic Potentiometers +VR VR 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 Hysterisis R2 VS VS - + VO 100K - VO + } } TL072 R1 R2 10K 10K +12V REV 1.1.2 12/8/00 VUL = {R1/(R1+R2)} VO(max) RLL = {R1/(R1+R2)} VO(min) 10K -12V www.xicor.com Characteristics subject to change without notice. 19 of 23 X9271 Application Circuits (continued) Attenuator Filter C VS + R2 R1 VS VO - - R VO + R3 R4 R2 R1 = R2 = R3 = R4 = 10k R1 GO = 1 + R2/R1 fc = 1/(2RC) 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 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 20 of 23 X9271 XX-ball BGA (X9271xxxxxxx) a a l j m k b b f Top View (Bump Side Down) Bottom View (Bump Side Up) Note: Drawing not to scale = Die Orientation mark d c e Side View (Bump Side Down) Millimeters Symbol Package Body Dimension X a Package Body Dimension Y b Package Height c Package Body Thickness d Ball Height e Ball Diameter f Total Ball Count g Ball Count X Axis h Ball Count Y Axis i Pins Pitch X Axis j Pins Pitch Y Axis k Edge to Ball Center (Corner) Distance Along X l Edge to Ball Center (Corner) Distance Along Y m REV 1.1.2 12/8/00 Min Nom. www.xicor.com Inches Max Min Nom. Characteristics subject to change without notice. Max 21 of 23 X9271 PACKAGING INFORMATION 14-LEAD PLASTIC, TSSOP, PACKAGE TYPE V .025 (.65) BSC .169 (4.3) .252 (6.4) BSC .177 (4.5) .193 (4.9) .200 (5.1) .047 (1.20) .0075 (.19) .0118 (.30) .002 (.05) .006 (.15) .010 (.25) Gage Plane 0- 8 Seating Plane .019 (.50) .029 (.75) Detail A (20X) .031 (.80) .041 (1.05) See Detail "A" NOTE: ALL DIMENSIONS IN INCHES (IN P ARENTHESES IN MILLIMETERS) REV 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 22 of 23 X9271 ORDERING INFORMATION X9271 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 V14 = 14-Lead SOIC xxx = xxx-Lead XBGA Potentiometer Organization Pot U= 50K T= 100K PART MARK CONVENTION xx Lead XBGA Top Mark X9271xxxx-2.7 X9271xxxx xx X9271 xxxx X9271xxxxx I-2.7 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 1.1.2 12/8/00 www.xicor.com Characteristics subject to change without notice. 23 of 23