Renesas ISL23415WFUZ-T7A

Overview

ISL23415WFUZ-T7A from Renesas Electronics is a volatile, low-voltage, 256-tap digitally controlled potentiometer (XDCP™) with SPI interface, 10kΩ end-to-end resistance, 10-lead MSOP package, and -40°C to +125°C operation - used for precision gain adjustment in battery-powered medical instruments and LCD bias compensation.

For engineers reviewing the ISL23415WFUZ-T7A datasheet, ISL23415WFUZ-T7A pinout, ISL23415WFUZ-T7A application, or ISL23415WFUZ-T7A equivalent, key selection criteria include VLOGIC=1.2V support for direct low-voltage bus interfacing, wiper settling time of 300ns, shutdown current <2.8µA, and guaranteed monotonicity in both voltage divider and rheostat modes.

Technical Context

The ISL23415WFUZ-T7A implements a monolithic CMOS resistor ladder with CMOS wiper switches operating in "make-before-break" mode, controlled via SPI Mode 0 (rising-edge clock, falling-edge data output). Its volatile Wiper Register (WR) defaults to 0x80 (mid-scale) at power-up and supports direct read/write over the serial bus.

It features dual-supply architecture: VCC (1.7V–5.5V) powers analog circuitry and DCP terminals, while VLOGIC (1.2V–5.5V) independently supplies logic and level-shifting circuitry - enabling interoperability with 1.2V microcontrollers without external level shifters and supporting daisy-chained multi-device configurations.

Key Specifications

Pinout & Package

ISL23415WFUZ-T7A is housed in a Pb-free, RoHS-compliant 10-lead MSOP package (M10.118), 3.0mm × 3.0mm × 1.0mm profile, suitable for high-density PCB layouts in space-constrained portable systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5170BRMZ-10 and MCP41HV51-103E/ST, the ISL23415WFUZ-T7A uniquely combines 1.2V logic compatibility, ultra-low shutdown current (<2.8µA), and guaranteed monotonicity - making it optimal for battery-powered, low-voltage, high-precision calibration where power and linearity are prioritized over nonvolatility or HV operation.

Availability

ISL23415WFUZ-T7A is available at Aetrix Electronics and suitable for power supply margining, RF amplifier biasing, LCD VCOM tuning, and portable medical calibration requiring stable component supply across extended temperature and low-power operation.

Supply support for ISL23415WFUZ-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 is a global semiconductor leader delivering microcontrollers, analog power, and connectivity solutions for automotive, industrial, and IoT applications.

The ISL23415 belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for replacing mechanical trimmers in battery-operated, space-constrained, and high-reliability systems requiring programmable analog tuning.

FAQ

What is the default wiper position of the ISL23415WFUZ-T7A at power-up?

The ISL23415WFUZ-T7A powers up with its volatile Wiper Register (WR) preset to 0x80 (128 decimal), placing the wiper at mid-scale - i.e., approximately 5kΩ between RH and RW, and 5kΩ between RW and RL for the 10kΩ version. This behavior is guaranteed across the full -40°C to +125°C temperature range and requires no host initialization to achieve a known, safe startup state.

Does the ISL23415WFUZ-T7A support daisy-chaining multiple units on a single SPI bus?

Yes, the ISL23415WFUZ-T7A supports daisy-chaining via its SDO output driving the SDI input of the next device. With CS and SCK shared across all units, a single microcontroller can configure multiple ISL23415WFUZ-T7A devices using reversed-order instruction sequencing - enabling synchronized wiper updates without additional GPIOs or chip-select lines.

What is the maximum SPI clock frequency supported by the ISL23415WFUZ-T7A?

The ISL23415WFUZ-T7A supports up to 5MHz SCK frequency when VLOGIC ≥1.7V. At lower logic voltages (1.2V ≤ VLOGIC < 1.7V), the maximum SCK frequency is reduced to 1MHz to ensure reliable timing margin. All timing parameters - including tSU, tH, tWH, and tWL - are specified and guaranteed across these ranges per the FN7780 Rev.3.00 datasheet.

How does the shutdown mode affect the wiper position and DCP terminals in the ISL23415WFUZ-T7A?

In shutdown mode (activated by setting SHDN bit in ACR), the ISL23415WFUZ-T7A opens the RH–RL path and internally shorts RW to RL through a 2kΩ resistor. Crucially, the current WR value is retained in volatile memory - so upon exit from shutdown, the wiper restores to its pre-shutdown position within 1.5µs, preserving calibration state without host reprogramming.

Can the ISL23415WFUZ-T7A be used in rheostat mode, and what are the key specifications in that configuration?

Yes, the ISL23415WFUZ-T7A operates in rheostat mode by connecting either RH or RL to a fixed potential and using RW and the unconnected terminal. In this mode, it delivers guaranteed monotonic RINL (±1 MI) and RDNL (±0.4 MI) for the 10kΩ version at VCC = 2.7–5.5V, with wiper resistance of 70Ω typical - making it suitable for programmable current-limiting and gain-setting applications where two-terminal variable resistance is required.