Renesas ISL23315WFUZ-TK

Overview

ISL23315WFUZ-TK from Renesas (formerly Intersil) is a volatile, single-channel, 256-tap digitally controlled potentiometer (DCP) with I²C interface, 10kΩ end-to-end resistance, ±0.5 LSB integral nonlinearity, and operation from 1.7V to 5.5V VCC and 1.2V to 5.5V VLOGIC. It serves as a precision programmable voltage divider or rheostat in bias compensation circuits for laser diodes and RF power amplifiers.

For engineers reviewing the ISL23315WFUZ-TK datasheet, ISL23315WFUZ-TK pinout, ISL23315WFUZ-TK application, or ISL23315WFUZ-TK equivalent, key selection criteria include its 10kΩ resistance option, 10-lead MSOP package, mid-scale power-on default (128), shutdown mode with RW–RL shorting, and independent VLOGIC supply enabling direct 1.2V bus interfacing without level shifters.

Technical Context

The ISL23315WFUZ-TK implements a monolithic CMOS resistor ladder with CMOS wiper switches operating in "make-before-break" mode, controlled by an 8-bit volatile Wiper Register (WR) accessible via I²C. Its architecture supports both voltage divider (RH–RL–RW) and rheostat (RW–RL or RW–RH) configurations with monotonic tap transitions.

It features dual-supply independence: analog VCC powers the DCP core (1.7V–5.5V), while digital VLOGIC (1.2V–5.5V) supplies the I²C interface and internal level shifter-enabling interoperability with low-voltage microcontrollers without external translation. Shutdown mode forces RH–RL open-circuit and internally connects RW to RL via ~2kΩ.

Key Specifications

Pinout & Package

ISL23315WFUZ-TK uses a 10-lead MSOP (M10.118) package with gull-wing leads and exposed thermal pad. Pin 1 is marked with dot; pin numbering follows standard MSOP top-view convention.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL23315WFUZ-TK, AD5170BRMZ-10 offers nonvolatility but sacrifices guaranteed mid-scale power-on and VLOGIC flexibility, while MCP45HV51-103E/MS extends voltage range at the cost of package size and low-voltage bus compatibility.

Availability

ISL23315WFUZ-TK is available at Aetrix Electronics and suitable for laser diode biasing, RF amplifier tuning, and LCD VCOM adjustment requiring stable component supply, extended temperature operation, and compact MSOP packaging.

Supply support for ISL23315WFUZ-TK 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 digitally controlled potentiometers for high-reliability industrial and communications systems.

The ISL23315WFUZ-TK belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for replacing mechanical trimmers in automated calibration, bias control, and power management circuits where programmability, repeatability, and small form factor are critical.

FAQ

What is the default wiper position of the ISL23315WFUZ-TK at power-on?

The ISL23315WFUZ-TK powers up with its volatile Wiper Register (WR) preset to 128 (0x80 hex), placing the wiper at mid-scale-i.e., approximately 5kΩ between RL and RW, and 5kΩ between RW and RH for the 10kΩ variant. This behavior is guaranteed across the full −40°C to +125°C temperature range and ensures predictable, safe startup in bias-critical applications like laser diode drivers.

Does the ISL23315WFUZ-TK support true 1.2V I²C bus operation?

Yes-the ISL23315WFUZ-TK accepts VLOGIC down to 1.2V, and its I²C interface (SCL/SDA/A0/A1) is fully functional at this level, including valid VIH/VIL thresholds and timing compliance. No external level shifter is needed when interfacing with 1.2V microcontrollers, as confirmed by the datasheet's VLOGIC = 1.2V operating condition tests for ILOGIC and ICC currents.

Can the ISL23315WFUZ-TK be used in rheostat mode, and what are the performance implications?

Yes-the ISL23315WFUZ-TK supports rheostat mode by connecting only RW and RL (or RW and RH), leaving the third terminal unconnected. In this configuration, it achieves ±1 MI integral nonlinearity and 220 ppm/°C resistance tempco (W option), making it suitable for programmable current-limiting or gain-setting networks where two-terminal variable resistance is required.

What happens to the wiper position during shutdown mode of the ISL23315WFUZ-TK?

In shutdown mode (SHDN bit = 0 in Access Control Register), the ISL23315WFUZ-TK opens the RH–RL path and internally shorts RW to RL via a ~2kΩ resistor. Crucially, the WR register contents are retained-so upon exit from shutdown, the wiper returns to its pre-shutdown tap position after a 1.5 µs recall time, preserving calibration state without host reinitialization.

Is the ISL23315WFUZ-TK RoHS compliant and lead-free?

Yes-the ISL23315WFUZ-TK is Pb-free and RoHS compliant, using 100% matte tin (e3) termination finish on its 10-lead MSOP package. It meets IPC/JEDEC J-STD-020 moisture sensitivity level requirements and is qualified for standard Pb-free reflow profiles, as documented in Intersil Tech Brief TB347 and the FN7778 datasheet revision notes.