Dual, 256-Tap, Low Voltage Digitally Controlled Potentiometer (XDCP) ISL23425 Features The ISL23425 is a volatile, low voltage, low noise, low power, Two potentiometers per package 256-tap, dual digitally controlled potentiometer (DCP) with an 256 resistor taps SPI Bus interface. It integrates two DCP cores, wiper switches 10k, 50k or 100k total resistance and control logic on a monolithic CMOS integrated circuit. SPI serial interface Each digitally controlled potentiometer is implemented with a - No additional level translator for low bus supply combination of resistor elements and CMOS switches. The - Daisy Chaining of multiple DCPs position of the wipers are controlled by the user through the SPI bus interface. Each potentiometer has an associated Maximum supply current without serial bus activity volatile Wiper Register (WRi, i = 0, 1) that can be directly written (standby) to and read by the user. The contents of the WRi controls the - 4A V and V = 5V CC LOGIC position of the wiper. When powered on, the wiper of each DCP - 1.7A V and V = 1.7V will always commence at mid-scale (128 tap position). CC LOGIC Shutdown Mode The low voltage, low power consumption, and small package of the ISL23425 make it an ideal choice for use in battery - Forces the DCP into an end-to-end open circuit and RWi is operated equipment. In addition, the ISL23425 has a V connected to RLi internally LOGIC pin allowing down to 1.2V bus operation, independent from the - Reduces power consumption by disconnecting the DCP V value. This allows for low logic levels to be connected CC resistor from the circuit directly to the ISL23425 without passing through a voltage Power supply level shifter. -V = 1.7V to 5.5V analog power supply CC The DCP can be used as a three-terminal potentiometer or as a -V = 1.2V to 5.5V SPI bus/logic power supply LOGIC two-terminal variable resistor in a wide variety of applications including control, parameter adjustments, and signal processing. Wiper resistance: 70 typical V = 3.3V CC Power-on preset to mid-scale (128 tap position) Applications Extended industrial temperature range: -40C to +125C Power supply margining 14 Ld TSSOP or 16 Ld TQFN packages Trimming sensor circuits Pb-free (RoHS compliant) Gain adjustment in battery powered instruments RF power amplifier bias compensation 10000 V REF 8000 RH1 6000 - V REF M 1 DCP RW1 4000 OF + ISL23325 ISL28114 2000 RL1 0 0 64 128 192 256 TAP POSITION (DECIMAL) FIGURE 1. FORWARD AND BACKWARD RESISTANCE vs TAP FIGURE 2. V ADJUSTMENT REF POSITION, 10k DCP June 20, 2011 CAUTION: These devices are sensitive to electrostatic discharge follow proper IC Handling Procedures. 1 1-888-INTERSIL or 1-888-468-3774 Copyright Intersil Americas Inc. 2011. All Rights Reserved FN7873.0 Intersil (and design) and XDCP are trademarks owned by Intersil Corporation or one of its subsidiaries. All other trademarks mentioned are the property of their respective owners RESISTANCE ()ISL23425 Block Diagram V V RH0 RH1 LOGIC CC SCK POWER UP SDI INTERFACE, SPI CONTROL WR0 SDO WR1 INTERFACE AND VOLATILE VOLATILE STATUS CS REGISTER REGISTER LOGIC AND AND WIPER WIPER CONTROL CONTROL CIRCUITRY CIRCUITRY RW0 RL0 RW1 RL1 GND Pin Configurations Pin Descriptions TSSOP TQFN SYMBOL DESCRIPTION ISL23425 (14 LD TSSOP) 1, 7 5, 6, 15 GND Ground pin TOP VIEW 216 V SPI bus/logic supply LOGIC Range 1.2V to 5.5V GND 1 14 V CC 3 1 SDO Logic Pin - Serial bus data output V 2 13 RL0 LOGIC (configurable) SDO 3 12 RW0 4 2 SCK Logic Pin - Serial bus clock input SCK 4 11 RH0 5 3 SDI Logic Pin - Serial bus data input SDI 5 10 RH1 64 CS Logic Pin - Active low chip select CS 6 9 RW1 8 8 RL1 DCP1 low terminal GND 7 8 RL1 99RW1 DCP1 wiper terminal 10 10 RH1 DCP1 high terminal ISL23425 11 11 RH0 DCP0 high terminal (16 LD TQFN) 12 12 RW0 DCP0 wiper terminal TOP VIEW 13 13 RL0 DCP0 low terminal 14 14 V Analog power supply. CC Range 1.7V to 5.5V 1 12 7 NC Not Connected SDO RW0 SCK 2 11 RH0 SDI 3 10 RH1 CS 4 9 RW1 FN7873.0 2 June 20, 2011 GND 5 16 V LOGIC GND 6 15 GND NC 7 14 V CC RL1 8 13 RL0