Renesas ISL22444WFV20Z

Overview

ISL22444WFV20Z from Renesas (formerly Intersil) is a quad digitally controlled potentiometer (XDCP™) with 256-tap resolution, SPI interface, non-volatile wiper storage, and dual-supply operation (VCC = 2.25–5.5V, V− = −2.25 to −5.5V). It integrates four independent 10kΩ DCPs in a 20-lead TSSOP package, supporting voltage divider and rheostat modes for precision analog control in industrial signal conditioning and bias adjustment circuits.

For engineers reviewing the ISL22444WFV20Z datasheet, ISL22444WFV20Z pinout, ISL22444WFV20Z application, or ISL22444WFV20Z equivalent, key selection criteria include its ±85 ppm/°C end-to-end tempco, 70Ω typical wiper resistance, 1.5µs wiper response time, shutdown current <4µA, and compatibility with daisy-chained SPI configurations across multiple devices.

Technical Context

The ISL22444WFV20Z implements four independent resistor arrays using CMOS switches and thin-film resistors, each with an 8-bit volatile Wiper Register (WRi) and non-volatile Initial Value Register (IVRi). Wiper positioning follows "make-before-break" switching to prevent open-circuit transients during tap changes.

It supports SPI Mode 0 (CPOL=0, CPHA=0), with SDO configurable as push-pull or open-drain output via ACR[1], and features 11 general-purpose non-volatile registers for lookup table storage. Power-up recalls IVRi contents into WRi, and shutdown mode forces RWi to RLi while opening RH–RL path.

Key Specifications

Pinout & Package

ISL22444WFV20Z is housed in a 20-lead TSSOP (M20.173) with exposed pad not connected internally. Pin functions are validated per FN6426 Rev 0.00 datasheet, Page 3.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar digitally controlled potentiometer applications.

Compared with ISL22444WFV20Z, ISL22424WFV20Z reduces channel count and memory depth but maintains pin compatibility and performance for simpler designs, while AD5242BRUZ10 trades SPI flexibility and bipolar capability for I²C simplicity in unipolar applications.

Availability

ISL22444WFV20Z is available at Aetrix Electronics and suitable for industrial sensor interfaces, precision instrumentation calibration, and programmable bias networks requiring stable component supply across extended temperature and long product lifecycles.

Supply support for ISL22444WFV20Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Renesas Electronics acquired Intersil in 2017 and continues to support its precision analog portfolio, including digitally controlled potentiometers and interface ICs for industrial and automotive markets.

The ISL22444WFV20Z belongs to Renesas' XDCP™ family, designed specifically for replacing mechanical potentiometers in automated calibration, adaptive biasing, and multi-channel analog trimming applications demanding non-volatility and wide temperature operation.

FAQ

What is the total resistance tolerance of the ISL22444WFV20Z?

The ISL22444WFV20Z has a total resistance tolerance of ±20% across the 10kΩ nominal value. This tolerance applies to the end-to-end resistance (RHi to RLi) and is specified over the full industrial temperature range (−40°C to +125°C). The device does not include factory trimming to tighten this tolerance, so system-level calibration may be required for absolute accuracy-critical applications.

Does the ISL22444WFV20Z support daisy-chaining via SPI?

Yes, the ISL22444WFV20Z supports daisy-chaining through its SPI interface. Multiple ISL22444WFV20Z devices can share a single CS line by connecting SDO of one device to SDI of the next, allowing sequential read/write operations without additional chip select signals. This is confirmed in the Applications Information section (Page 14) of the FN6426 datasheet.

What happens to the wiper position of the ISL22444WFV20Z during power-up?

At power-up, the ISL22444WFV20Z first resets all Wiper Registers (WRi) to 0x80 (mid-scale), then loads the stored values from the non-volatile Initial Value Registers (IVRi) into the corresponding WRi. Since IVRi registers are factory-programmed to 0x80, the wiper defaults to mid-scale unless previously written to a different value and stored in non-volatile memory.

Can the ISL22444WFV20Z operate with only a unipolar supply?

Yes, the ISL22444WFV20Z can operate with a unipolar supply: connect V− to GND and use VCC = 2.25–5.5V. In this configuration, DCP terminals swing from GND to VCC. However, the full benefit of bipolar operation (e.g., AC signal attenuation) is lost, and wiper leakage specs assume V− is actively biased - verify ILkgDCP (≤1µA) under actual operating conditions.

How is shutdown mode activated on the ISL22444WFV20Z?

Shutdown mode is activated by setting the SHDN bit (ACR[6]) to 0 via the SPI interface. When active, each DCP disconnects its RH–RL path and shorts RWi to RLi. The device exits shutdown and restores prior wiper positions when SHDN is set back to 1. This behavior is defined in the Access Control Register (ACR) description on Page 12 of the FN6426 datasheet.