Renesas ISL23318UFUZ

Overview

ISL23318UFUZ from Renesas Electronics is a volatile, low-voltage, I²C-compatible digitally controlled potentiometer (DCP) with 128 taps, 10kΩ total resistance, and operation from 1.7V to 5.5V VCC and 1.2V to 5.5V VLOGIC. It features 70Ω typical wiper resistance at 3.3V, ±0.15 LSB integral nonlinearity, and shutdown mode with <2.8µA max current. It serves as a precision voltage divider or rheostat in battery-powered sensor trimming and power supply margining.

For engineers reviewing the ISL23318UFUZ datasheet, ISL23318UFUZ pinout, ISL23318UFUZ application, or ISL23318UFUZ equivalent, key selection criteria include I²C address configurability (A0/A1), dual-supply independence (VLOGIC/VCC), mid-scale power-on default, and guaranteed monotonicity across -40°C to +125°C.

Technical Context

The ISL23318UFUZ implements a resistor ladder with CMOS switches in a monolithic CMOS IC, supporting both voltage divider (RH–RL–RW) and rheostat (RW–RL or RW–RH) configurations. Its 7-bit volatile Wiper Register (WR) directly controls tap position, with power-on reset to 64 (mid-scale).

It uses make-before-break switching for glitch-free wiper transitions and integrates an I²C interface with level-shifting logic powered by VLOGIC - enabling direct connection to 1.2V microcontrollers without external translators. Shutdown mode forces RH–RL open-circuit while shorting RW to RL via ~2kΩ.

Key Specifications

Pinout & Package

ISL23318UFUZ is packaged in a 10-lead UTQFN (2.1mm × 1.6mm, 0.5mm pitch), RoHS-compliant, with wettable flanks for automated optical inspection.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5170BRMZ-10 and MCP4017T-103E/OT, the ISL23318UFUZ uniquely balances ultra-low-voltage I²C operation (1.2V), 128-tap resolution, and guaranteed monotonicity - making it optimal for battery-powered calibration where startup predictability and analog precision are prioritized over nonvolatility or footprint minimization.

Availability

ISL23318UFUZ 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 ranges.

Supply support for ISL23318UFUZ 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 high-performance analog, mixed-signal, and embedded processing solutions for industrial, automotive, and infrastructure markets.

The ISL23318UFUZ belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, designed specifically for precision, low-power, and wide-temperature analog trimming in resource-constrained embedded systems.

FAQ

What is the default wiper position of the ISL23318UFUZ at power-on?

The ISL23318UFUZ powers up with its volatile Wiper Register (WR) preset to 64 (0x40 hex), placing the wiper at mid-scale - i.e., 50% of the 10kΩ total resistance between RH and RL. This behavior is guaranteed across the full -40°C to +125°C operating range and ensures a known, safe startup state for biasing and gain-setting circuits using the ISL23318UFUZ.

Does the ISL23318UFUZ support true 1.2V I²C communication?

Yes - the ISL23318UFUZ features a dedicated VLOGIC pin that accepts 1.2V to 5.5V, enabling direct connection to 1.2V I²C masters without external level shifters. Its input thresholds scale with VLOGIC (VIH = 0.7×VLOGIC, VIL = 0.3×VLOGIC), and it drives SDA with rail-to-rail logic compatible down to 1.2V, confirming full functional interoperability at 1.2V bus voltage in the ISL23318UFUZ.

Can the ISL23318UFUZ be used in rheostat mode, and what are the key specifications in that configuration?

Yes - the ISL23318UFUZ supports rheostat mode by connecting only RW and RL (or RW and RH), leaving the third terminal unconnected. In this mode, it achieves ±0.15 MI differential nonlinearity and 0.3–1.0 MI zero-scale error (10kΩ option), with wiper resistance remaining 70Ω typical. The ISL23318UFUZ maintains monotonicity and operates across the full -40°C to +125°C range in rheostat configuration.

What happens to the wiper setting during shutdown mode of the ISL23318UFUZ?

In shutdown mode (SHDN bit = 0 in Access Control Register), the ISL23318UFUZ opens the RH–RL path and internally connects RW to RL via a ~2kΩ resistor. Crucially, the volatile Wiper Register contents are preserved - so upon exit from shutdown, the ISL23318UFUZ restores the exact prior tap position after a 1.5µs recall time, ensuring seamless resumption of analog control without reprogramming.

How many ISL23318UFUZ devices can share the same I²C bus, and how is addressing managed?

Up to four ISL23318UFUZ devices can operate on a single I²C bus, using pins A0 and A1 to configure the two least-significant bits of the 7-bit slave address. Each combination of A0/A1 (GND/GND, GND/VLOGIC, VLOGIC/GND, VLOGIC/VLOGIC) yields a unique address - allowing independent read/write access to each ISL23318UFUZ without hardware contention or software arbitration overhead.