Renesas ISL23318WFUZ

Overview

ISL23318WFUZ from Renesas Electronics is a volatile, low-voltage, 128-tap digitally controlled potentiometer (XDCP™) with I²C interface, 10kΩ total resistance, 70Ω typical wiper resistance at 3.3V, 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 battery-powered sensor trimming and power supply margining circuits.

For engineers reviewing the ISL23318WFUZ datasheet, ISL23318WFUZ pinout, ISL23318WFUZ application, or ISL23318WFUZ equivalent, key selection considerations include its dual-supply I²C compatibility (down to 1.2V logic), mid-scale power-on default, shutdown mode with internal RW–RL short, ±0.15 LSB monotonicity, and -40°C to +125°C extended industrial temperature range.

Technical Context

The ISL23318WFUZ implements a monolithic CMOS resistor ladder with CMOS switch-based wiper control, using a volatile 7-bit Wiper Register (WR) directly accessible via I²C. Its "make-before-break" switching ensures glitch-free tap transitions, and the WR resets to 64 (mid-scale) on power-up.

It supports up to four devices per I²C bus via hardwired A0/A1 address pins, operates with independent analog (VCC) and logic (VLOGIC) supplies, and enters shutdown mode via the SHDN bit in the Access Control Register - forcing RH–RL open-circuit while shorting RW to RL through ~2kΩ.

Key Specifications

Pinout & Package

ISL23318WFUZ is packaged in a Pb-free, RoHS-compliant 10-lead UTQFN (2.1mm × 1.6mm, 0.5mm pitch) with wettable flanks. Pin mapping is validated per Renesas FN7887 Rev 1.00, Page 2 (UTQFN top view).

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 ISL23318WFUZ uniquely combines 1.2V I²C compatibility, mid-scale power-on default, and shutdown-mode RW–RL short - making it optimal for battery-constrained, safety-critical, or mixed-voltage embedded systems requiring deterministic startup behavior.

Availability

ISL23318WFUZ is available at Aetrix Electronics and suitable for battery-powered instrumentation, sensor signal conditioning, power supply margining, and RF bias control requiring stable component supply across extended temperature and low-voltage operation.

Supply support for ISL23318WFUZ 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 trusted embedded solutions for automotive, industrial, infrastructure, and IoT applications, with deep expertise in analog, power, and timing products.

The ISL23318 belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for replacing mechanical potentiometers in precision, low-power, and thermally demanding environments where programmability, reliability, and small footprint are essential.

FAQ

What is the default wiper position of the ISL23318WFUZ at power-up?

At power-up, the ISL23318WFUZ wiper always initializes to mid-scale (64 out of 128 taps, corresponding to hexadecimal 40h), regardless of prior state. This behavior is hardwired and guaranteed across the full -40°C to +125°C operating range, ensuring predictable startup in safety-critical applications like power supply feedback loops or sensor bias networks.

Does the ISL23318WFUZ support I²C communication below 1.8V logic levels?

Yes - the ISL23318WFUZ supports I²C bus operation down to 1.2V via its dedicated VLOGIC pin, enabling direct interface with 1.2V and 1.8V microcontrollers without external level shifters. The SDA and SCL inputs are fully specified for VIH ≥ 0.7×VLOGIC and VIL ≤ 0.3×VLOGIC, and the device draws only 5µA ILOGIC current at 1.2V/1.7V supply conditions.

How does shutdown mode affect the terminals of the ISL23318WFUZ?

In shutdown mode (activated by setting SHDN bit in ACR), the ISL23318WFUZ forces an open circuit between RH and RL while internally shorting RW to RL through a ~2kΩ resistor. This configuration isolates the high-side path and provides a defined low-impedance sink at RW - critical for fail-safe biasing in RF amplifiers or preventing floating nodes in sensor interfaces.

What is the maximum recommended wiper current for continuous operation of the ISL23318WFUZ?

The ISL23318WFUZ specifies a maximum continuous wiper current (IW) of ±3mA under recommended operating conditions. Exceeding this limit risks increased wiper resistance drift, accelerated wear of CMOS switches, or violation of absolute maximum ratings. For applications requiring higher current, external buffer amplifiers should be used to isolate the DCP from load demands.

Can multiple ISL23318WFUZ devices share the same I²C bus?

Yes - up to four ISL23318WFUZ devices can operate on a single I²C bus using the A0 and A1 address pins, which configure the two least-significant bits of the 7-bit slave address. Each device must have a unique combination of A0/A1 tied to VLOGIC or GND, yielding addresses 0x28–0x2B. No external address jumpers or configuration registers are required.