Renesas ISL23418TFUZ-T7A

Overview

ISL23418TFUZ-T7A from Renesas Electronics (formerly Intersil) is a volatile, single-channel, 128-tap digitally controlled potentiometer (XDCP™) with SPI interface, 100kΩ end-to-end resistance, 70Ω typical wiper resistance at 3.3V, and operation from 1.7V to 5.5V analog supply. It serves as a precision programmable voltage divider or rheostat in low-power, high-temperature analog signal conditioning circuits.

For engineers reviewing the ISL23418TFUZ-T7A datasheet, ISL23418TFUZ-T7A pinout, ISL23418TFUZ-T7A application, or ISL23418TFUZ-T7A equivalent, this page delivers verified specifications, validated µTQFN-10 pin mapping, confirmed industrial temperature support (–40°C to +125°C), and real-world use cases in power margining and RF bias control - all derived from FN7901 Rev 1.00.

Technical Context

The ISL23418TFUZ-T7A implements a monolithic CMOS resistor ladder with 128 discrete taps and "make-before-break" CMOS wiper switches, controlled via an 8-bit volatile Wiper Register (WR) accessible over SPI Mode 0. Its dual-supply architecture separates VCC (1.7V–5.5V analog) from VLOGIC (1.2V–5.5V logic), enabling direct interfacing with 1.2V microcontrollers without level shifters.

It features hardware shutdown mode (SHDN bit in ACR) that forces RH–RL open-circuit while shorting RW to RL via ~2kΩ, with <2.8µA max shutdown current. Power-on defaults WR to 64 (mid-scale), and wiper settling time is 300ns for large-signal transitions.

Key Specifications

Pinout & Package

ISL23418TFUZ-T7A is housed in a RoHS-compliant 10-lead µTQFN package (2.1mm × 1.6mm, 0.5mm pitch, L10.2.1x1.6A), optimized for space-constrained portable and automotive PCBs.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5170BRMZ-100 and MCP41HV51-104E/MF, the ISL23418TFUZ-T7A offers superior low-voltage operation (1.2V logic), smallest footprint (µTQFN-10), and lowest shutdown current - making it optimal for space- and power-constrained embedded systems where settings are managed by host firmware.

Availability

ISL23418TFUZ-T7A is available at Aetrix Electronics and suitable for power supply margining, RF amplifier bias compensation, LCD bias tuning, and portable medical calibration requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ISL23418TFUZ-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, including XDCP™ digitally controlled potentiometers, with focus on high-reliability industrial and automotive applications.

The ISL23418TFUZ-T7A belongs to Renesas' XDCP™ family, designed specifically for replacing mechanical potentiometers in automated calibration, adaptive biasing, and programmable gain/offset circuits where SPI control, low power, and extended temperature operation are essential.

FAQ

What is the default wiper position of the ISL23418TFUZ-T7A at power-up?

The ISL23418TFUZ-T7A powers up with its volatile Wiper Register (WR) preset to 64 (hex 40), placing the wiper at mid-scale - exactly halfway between RL and RH terminals. This behavior is guaranteed across all operating conditions and ensures a known, safe initial state for downstream circuitry without requiring host initialization.

Can the ISL23418TFUZ-T7A operate with a 1.2V microcontroller SPI bus?

Yes - the ISL23418TFUZ-T7A supports VLOGIC down to 1.2V, allowing direct connection to 1.2V I/O domains without level shifters. Its input thresholds scale with VLOGIC (VIH = 0.7×VLOGIC, VIL = 0.3×VLOGIC), and SCK frequency is rated to 1MHz at 1.2V, ensuring robust communication in ultra-low-power systems.

Does the ISL23418TFUZ-T7A retain wiper position during shutdown mode?

Yes - when the SHDN bit in the Access Control Register is asserted, the ISL23418TFUZ-T7A enters shutdown mode but retains the current WR register value. Upon exit, the wiper returns to its pre-shutdown position within 1.5µs, enabling rapid resumption of analog control without host reprogramming.

What is the maximum DCP terminal voltage allowed on the ISL23418TFUZ-T7A?

The ISL23418TFUZ-T7A specifies that voltage on RH, RL, or RW pins must remain within 0V to VCC at all times - including during power-up, power-down, and normal operation. Exceeding this range risks latch-up or permanent damage, as the device lacks internal clamping diodes to VCC or GND.

How does the ISL23418TFUZ-T7A handle daisy-chained SPI configurations?

The ISL23418TFUZ-T7A supports daisy chaining via SDO-to-SDI interconnection across multiple units, sharing SCK and CS lines. Each device shifts out its read data on SDO during the third and fourth bytes of a four-byte read cycle, enabling synchronized multi-device programming without additional chip selects.