AD5232 8-Bit Dual Nonvolatile Memory Digital Potentiometer Data Sheet

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8-Bit Dual Nonvolatile Memory Digital Potentiometer

AD5232

FEATURES FUNCTIONAL BLOCK DIAGRAM Nonvolatile Memory Preset Maintains Wiper Settings Dual Channel, 256-Position Resolution

AD5232

Full Monotonic Operation DNL < 1 LSB

CS VDD

10 k
, 50 k
, 100 k
Terminal Resistance

ADDR RDAC1 RDAC1

Linear or Log Taper Settings DECODE REGISTER

SDI SDI

Push-Button Increment/Decrement Compatible

SPI-Compatible Serial Data Input with Readback SERIAL

GND EEMEM1 B1

INTERFACE

Function 3 V to 5 V Single Supply or 2.5 V Dual Supply

RDAC2 RDAC2

SDO SDO

Operation REGISTER A2

14 Bytes of User EEMEM Nonvolatile Memory for WP

EEMEM W2 Constant Storage CONTROL

EEMEM2

Permanent Memory Write Protection

14 BYTES

USER EEMEM VSS

100-Year Typical Data Retention TA = 55C

APPLICATIONS

Mechanical Potentiometer Replacement The basic mode of adjustment is the increment and decrement Instrumentation: Gain, Offset Adjustment command controlling the present setting of the Wiper position

IN setting (RDAC) register. An internal scratch pad RDAC register

Programmable Voltage-to-Current Conversion

-T -E IS TA

Programmable Filters, Delays, Time Constants can be moved UP or DOWN one step of the nominal terminal Line Impedance Matching resistance between terminals A and B. This linearly changes the Power Supply Adjustment wiper to B terminal resistance (RWB) by one position segment of DIP Switch Setting the devices’ end-to-end resistance (RAB). For exponential/loga- rithmic changes in wiper setting, a left/right shift command adjusts levels in ±6 d B steps, which can be useful for audio and

GENERAL DESCRIPTION

light alarm applications.

The AD5232 device provides a nonvolatile, dual-channel,

digitally controlled variable resistor (VR) with 256-position The AD5232 is available in a thin TSSOP-16 package. All parts resolution. These devices perform the same electronic adjust- are guaranteed to operate over the extended industrial tempera- ment function as a potentiometer or variable resistor. The ture range of –40°C to +85°C. An evaluation board is available, AD5232’s versatile programming via a microcontroller allows Part Number: AD5232EVAL.

multiple modes of operation and adjustment. In the direct program mode a predetermined setting of the RDAC register can be loaded directly from the microcontroller. Another key mode of operation allows the RDAC register to be refreshed with the setting previously stored in the EEMEM register. When changes are made to the RDAC register to estab- lish a new wiper position, the value of the setting can be saved into the EEMEM by executing an EEMEM save operation. Once the settings are saved in the EEMEM register these values will be automatically transferred to the RDAC register to set the wiper position at system power ON. Such operation is enabled by the internal preset strobe and the preset can also be accessed externally.

RWB RWA

All internal register contents can be read out of the serial data output (SDO). This includes the RDAC1 and RDAC2 registers, the corresponding nonvolatile EEMEM1 and EEMEM2 regis-

CODE – Decimal

ters, and the 14 spare USER EEMEM registers available for constant storage.

Figure 1. Symmetrical RDAC Operation

*Patent pending.

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