X9438 Programmable Analog PRELIMINARY Data Sheet March 11, 2005 FN8199.0 DESCRIPTION Dual Digitally Controlled Potentiometer (XDCP) with Operational Amplifier The X9438 is a monolithic CMOS IC that incorporates two operational amplifiers and two nonvolatile digitally FEATURES controlled potentiometers. The amplifiers are CMOS differential input voltage operational amplifiers with Two CMOS voltage operational amplifiers near rail-to-rail outputs. All pins for the two amplifiers Two digitally controlled potentiometers are brought out of the package to allow combining Can be combined or used separately them with the potentiometers, or using them as com- Amplifiers: plete stand-alone amplifiers. Low voltage operation V+/V- = 2.7V to 5.5V The digitally controlled potentiometers consist of a Rail-to-rail CMOS performance series string of 63 polycrystalline resistors that behave 1MHz gain bandwidth product as standard integrated circuit resistors. The two-wire Digitally controlled potentiometers serial port, common to both pots, allows the user to Dual 64 tap potentiometers program the connection of the wiper output to any of R = 10k total the resistor nodes in the series string. The wiper posi- 2-wire serial interface tion is saved in the on board E2 memory to allow for V = 2.7V to 5.5V CC nonvolatile restoration of the wiper position. A wide variety of applications can be implemented using the potentiometers and the amplifiers. A typical application is to implement the amplifier as a wiper buffer in circuits that use the potentiometer as a voltage reference. The potentiometer can also be combined with the amplifier yielding a digitally programmable gain amplifier or programmable current source. BLOCK DIAGRAM V R R R CC W0 H0 L0 V+ V NI0 Control and + Memory V SCL OUT0 SDA WCR0 A3 V INV0 A2 V NI1 A1 + A0 V OUT1 WP WCR1 V INV1 R R R V V- W1 L1 H1 SS CAUTION: These devices are sensitive to electrostatic discharge follow proper IC Handling Procedures. 1 1-888-INTERSIL or 1-888-352-6832 Intersil (and design) is a registered trademark of Intersil Americas Inc. XDCP is a trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. NOT RECOMMENDED FOR NEW DESIGNS NO RECOMMENDED REPLACEMENT contact our Technical Support Center at 1-888-INTERSIL or www.intersil.com/tscX9438 PIN DESCRIPTIONS Analog Supplies V+, V- The analog supplies V+, V- are the supply voltages for Host Interface Pins the XDCP analog section and the operational amplifiers. Serial Clock (SCL) System Supply V and Ground V . CC SS The SCL input is used to clock data into and out of the The system supply V and its reference V is used CC SS X9438. to bias the interface and control circuits. Serial Data (SDA) PIN CONFIGURATION SDA is a bidirectional pin used to transfer data into and out of the device. It is an open drain output and SOIC TSSOP may be wire-ORed with any number of open drain or V 1 CC 24 V+ NC 1 A 24 3 open collector outputs. An open drain output requires A R SCL 2 V 0 L0 23 2 OUT0 23 the use of a pull-up resistor. V R 3 V INV0 3 V H0 22 22 NI0 INV1 V R 4 NI0 W0 21 V 4 V 21 INV0 NI1 Device Address (A - A ) 0 3 V A 5 OUT0 20 A0 5 V 2 20 OUT1 The address inputs are used to set the least significant WP V+ V- 6 NC 6 19 19 4 bits of the 8-bit slave address. A match in the slave X9438 X9438 SDA V 7 18 A CC 7 V 18 3 SS address serial data stream must be made with the A1 R 8 SCL 17 L0 8 R 17 W1 address input in order to initiate communication with R R 9 9 16 V H0 16 R L1 INV1 H1 the X9438. A maximum of 16 devices may share the R 10 W0 R 15 10 R V 15 H1 L1 NI1 same 2-wire serial bus. R 11 W1 14 A 11 V 14 A 2 OUT1 1 V (1) 12 13 WR SS 12 13 V- SDA Potentiometer Pins R (R - R ), R (R - R ) H H0 H1 L L0 L1 PIN NAMES The R and R inputs are equivalent to the terminal con- H L nections on either end of a mechanical potentiometer. Symbol Description SCL Serial Clock R (R - R ) W W0 W1 SDA Serial Data The wiper output is equivalent to the wiper output of a mechanical potentiometer. A0 - A3 Device Address R - R , Potentiometers (terminal equivalent) H0 H1 Amplifier and Device Pins R - R L0 L1 R - R Potentiometers (wiper equivalent) W0 W1 Amplifier Input Voltage V (0,1) and V (0,1) NI INV V , Amplifier Input Voltages NI(0,1) V and V are inputs to the noninverting (+) and NI INV V INV(0,1) inverting (-) inputs of the operational amplifiers. V V Amplifier Outputs OUT0, OUT1 Amplifier Output Voltage V (0,1) WP Hardware Write Protection OUT V is the voltage output pin of the operational V+,V- Analog and Voltage Amplifier Supplies OUT amplifier. V System/Digital Supply Voltage CC V System Ground Hardware Write Protect Input WP SS NC No Connection The WP pin, when low, prevents non-volatile writes to the wiper counter registers. Note: (1) Alternate designations for R , R , R are V , V , V H L W H L W FN8199.0 2 March 11, 2005