Renesas ISL23328WFRUZ-T7A

Overview

ISL23328WFRUZ-T7A from Renesas (formerly Intersil) is a dual, volatile, 128-tap digitally controlled potentiometer (DCP) with I²C interface, 10kΩ total resistance, 16-pin UTQFN package, and extended industrial temperature range (–40°C to +125°C). It functions as two independent programmable resistive dividers in battery-powered sensor trimming, power supply margining, and RF bias compensation circuits.

For engineers reviewing the ISL23328WFRUZ-T7A datasheet, ISL23328WFRUZ-T7A pinout, ISL23328WFRUZ-T7A application, or ISL23328WFRUZ-T7A equivalent, key selection criteria include its 1.2V–5.5V VLOGIC independence, 70Ω typical wiper resistance at 3.3V, ±3mA max wiper current, shutdown mode with end-to-end open circuit, and guaranteed monotonicity in both voltage divider and rheostat modes.

Technical Context

The ISL23328WFRUZ-T7A integrates two independent DCP cores on a monolithic CMOS die, each with an 8-bit volatile Wiper Register (WR0/WR1) directly accessible via I²C. Its "make-before-break" switch architecture ensures glitch-free wiper transitions, and internal level shifting enables direct connection to 1.2V logic without external translators.

It operates in two primary configurations: voltage divider mode (RH–RL–RW) with 0.15 LSB typical INL/DNL and ratiometric temperature coefficient of 8 ppm/°C, and rheostat mode (RW–RL or RW–RH) with 0.5 MI typical RINL/RDNL. Power-on defaults WR0 and WR1 to 64 (mid-scale), and shutdown mode disconnects RH terminals while connecting RW to RL through a 2kΩ resistor.

Key Specifications

Pinout & Package

ISL23328WFRUZ-T7A is housed in a 16-lead, 2.6mm × 1.8mm, 0.5mm pitch UTQFN package (Pb-free, RoHS compliant, 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 MCP45HV51-103E/MS, the ISL23328WFRUZ-T7A uniquely combines dual 128-tap DCPs, 1.2V–5.5V VLOGIC independence, and UTQFN space savings - making it optimal for compact, multi-rail, battery-constrained systems requiring coordinated analog tuning.

Availability

ISL23328WFRUZ-T7A is available at Aetrix Electronics and suitable for power supply margining, sensor trimming, RF bias compensation, and battery-powered instrument gain control requiring stable component supply across extended temperature and low-voltage operation.

Supply support for ISL23328WFRUZ-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 Corporation acquired Intersil in 2017 and continues to manufacture and support its precision analog portfolio, including digitally controlled potentiometers.

The ISL23328WFRUZ-T7A belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for replacing mechanical trimpots in automated calibration, adaptive biasing, and low-power analog reconfiguration systems.

FAQ

What is the default wiper position of the ISL23328WFRUZ-T7A at power-on?

The ISL23328WFRUZ-T7A powers up with both Wiper Registers (WR0 and WR1) preset to 0x40 (64 decimal), placing each wiper at the exact mid-scale tap position (64 of 128) between RH and RL terminals. This behavior is hard-coded and occurs regardless of prior shutdown state or register contents, ensuring a known, safe startup condition for feedback-sensitive circuits.

Does the ISL23328WFRUZ-T7A support true 1.2V I²C bus operation?

Yes, the ISL23328WFRUZ-T7A fully supports 1.2V I²C bus operation via its dedicated VLOGIC pin, which powers the digital interface and internal level shifter. Input thresholds scale with VLOGIC (VIH = 0.7×VLOGIC), and SDA/SCL operate reliably down to 1.2V without external translators - confirmed per datasheet Section "Serial Interface Specification" and Figure 21 startup waveforms.

Can the ISL23328WFRUZ-T7A be used in rheostat mode, and what are its linearity specifications?

Yes, the ISL23328WFRUZ-T7A supports rheostat mode (RW–RL or RW–RH) with guaranteed monotonicity. For the 10kΩ version, Integral Non-linearity (RINL) is ±0.5 MI and Differential Non-linearity (RDNL) is ±0.15 MI over 2.7V–5.5V VCC - verified in datasheet Table "Analog Specifications" under "RHEOSTAT MODE" and Figures 7–8.

What happens to the wiper terminals during shutdown mode of the ISL23328WFRUZ-T7A?

In shutdown mode (SHDN bit = 0 in ACR register), the ISL23328WFRUZ-T7A forces all RH terminals into high-impedance open-circuit and internally connects each RW terminal to its corresponding RL terminal through a 2kΩ series resistor. This configuration isolates the DCP array from external circuitry while maintaining wiper register values, reducing total supply current to <2µA.

How does the ISL23328WFRUZ-T7A ensure matching between its two DCP channels?

The ISL23328WFRUZ-T7A guarantees DCP-to-DCP matching of ±0.5 LSB in voltage divider mode (Vmatch parameter), measured with identical tap positions and terminal voltages applied to both DCPs. This matching is process-trimmed on-die and specified over –40°C to +125°C - critical for differential applications like programmable instrumentation amplifiers and balanced sensor bridges.