Renesas ISL23418WFUZ-T7A

Overview

ISL23418WFUZ-T7A from Renesas (formerly Intersil) is a volatile, single-channel, 128-tap digitally controlled potentiometer (XDCP™) with SPI interface, 10kΩ end-to-end resistance, ±0.15 LSB integral nonlinearity, and operation from 1.2V logic supply independent of 1.7–5.5V analog supply. It serves as a programmable voltage divider or rheostat in precision biasing and gain control circuits.

For engineers reviewing the ISL23418WFUZ-T7A datasheet, ISL23418WFUZ-T7A pinout, ISL23418WFUZ-T7A application, or ISL23418WFUZ-T7A equivalent, this device supports daisy-chained SPI configuration, mid-scale power-on default (64-tap), shutdown mode with RW–RL short, and operation across –40°C to +125°C industrial temperature range.

Technical Context

The ISL23418WFUZ-T7A implements a monolithic CMOS resistor ladder with CMOS wiper switches and integrated SPI interface logic operating in Mode 0 (CPOL = 0, CPHA = 0). Its volatile Wiper Register (WR) directly controls tap position, with make-before-break switching ensuring glitch-free transitions.

It features dual-supply architecture: VLOGIC (1.2–5.5V) powers digital I/O and level-shifting circuitry, while VCC (1.7–5.5V) supplies the analog DCP core. Shutdown mode forces RH–RL open-circuit and internally shorts RW to RL via ~2kΩ, with wiper state preserved for fast recall.

Key Specifications

Pinout & Package

ISL23418WFUZ-T7A is housed in a 10-lead µTQFN package (2.1 mm × 1.6 mm, 0.5 mm pitch, RoHS-compliant, moisture sensitivity level MSL3).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5170BRMZ-10 and MCP41HV51-103, the ISL23418WFUZ-T7A uniquely combines 1.2V logic compatibility, daisy-chain SPI, and guaranteed mid-scale power-on behavior-making it optimal for battery-powered, thermally demanding, and multi-device calibration systems requiring deterministic initialization.

Availability

ISL23418WFUZ-T7A is available at Aetrix Electronics and suitable for power supply margining, RF amplifier biasing, LCD bias compensation, and portable medical calibration requiring stable component supply across extended temperature and long product lifecycles.

Supply support for ISL23418WFUZ-T7A 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 maintains its precision analog portfolio, emphasizing high-reliability, automotive-qualified, and industrial-grade interface and signal-conditioning ICs.

The ISL23418WFUZ-T7A belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for replacing mechanical potentiometers in automated calibration, adaptive biasing, and programmable gain control applications where SPI configurability and extended temperature operation are essential.

FAQ

What is the default wiper position of the ISL23418WFUZ-T7A at power-up?

The ISL23418WFUZ-T7A powers up with its volatile Wiper Register (WR) preset to 64 (decimal), corresponding to the mid-scale tap position (40h hex). This ensures a known, symmetrical starting point for voltage division or rheostat operation-critical for avoiding transient overvoltage or undefined bias conditions in sensitive analog circuits. The ISL23418WFUZ-T7A does not retain wiper position across power cycles.

Can the ISL23418WFUZ-T7A operate with different analog and logic supply voltages?

Yes-the ISL23418WFUZ-T7A supports independent analog (VCC = 1.7–5.5V) and logic (VLOGIC = 1.2–5.5V) supplies. This allows direct connection to low-voltage microcontrollers (e.g., 1.2V or 1.8V I/O) without external level shifters, while powering the DCP core from a higher analog rail (e.g., 3.3V or 5V). The ISL23418WFUZ-T7A's internal level shifter ensures robust SPI communication across this voltage separation.

Does the ISL23418WFUZ-T7A support daisy-chaining multiple devices on a single SPI bus?

Yes-the ISL23418WFUZ-T7A supports daisy-chain configuration: connect the SDO of one device to the SDI of the next, while sharing CS and SCK lines. This enables simultaneous write operations to multiple ISL23418WFUZ-T7A units using a single chip select, reducing GPIO usage and simplifying layout in multi-channel systems such as multi-sensor bias networks or programmable filter banks.

What happens to the wiper terminal during shutdown mode of the ISL23418WFUZ-T7A?

In shutdown mode (SHDN bit = 0 in ACR), the ISL23418WFUZ-T7A forces RH–RL into an open circuit and internally shorts RW to RL through a ~2kΩ resistor. This provides a defined, low-impedance termination path while preserving the current WR value. Upon exit from shutdown, the wiper returns to its pre-shutdown position after ≤1.5 µs settling time-ensuring rapid, predictable recovery without recalibration.

What is the maximum SPI clock frequency supported by the ISL23418WFUZ-T7A?

The ISL23418WFUZ-T7A supports up to 5 MHz SCK frequency when VLOGIC ≥ 1.7V, and up to 1 MHz when VLOGIC is 1.2–1.6V. Timing parameters-including tSU (50 ns), tH (50 ns), and tCYC (200 ns)-are fully specified across this range. The ISL23418WFUZ-T7A operates in SPI Mode 0 (CPOL = 0, CPHA = 0), with data latched on the rising edge of SCK and output on the falling edge.