Renesas ISL23318UFUZ-TK

Overview

ISL23318UFUZ-TK from Renesas Electronics is a volatile, low-voltage, 128-tap digitally controlled potentiometer (DCP) with I²C interface, 10kΩ total resistance, ±0.15 LSB integral nonlinearity, and operation from 1.7V to 5.5V VCC and 1.2V to 5.5V VLOGIC. It functions as a precision voltage divider or rheostat in trimming, gain control, and bias compensation circuits.

For engineers reviewing the ISL23318UFUZ-TK datasheet, ISL23318UFUZ-TK pinout, ISL23318UFUZ-TK application, or ISL23318UFUZ-TK equivalent, key selection considerations include its dual-supply I²C compatibility (VLOGIC independent of VCC), mid-scale power-on default (64 tap), shutdown mode with RW-to-RL shorting, and extended industrial temperature range (–40°C to +125°C).

Technical Context

The ISL23318UFUZ-TK implements a monolithic CMOS resistor ladder with CMOS wiper switches and integrated I²C interface logic. Its volatile Wiper Register (WR) is directly readable/writable over I²C, and wiper position changes use make-before-break switching to prevent open-circuit transients.

It supports up to four devices per I²C bus via hardwired A0/A1 address pins, operates down to 1.2V logic levels without level shifters, and features dedicated VLOGIC and VCC supplies enabling mixed-voltage system integration - e.g., 1.8V microcontroller interfacing with 3.3V analog signal paths.

Key Specifications

Pinout & Package

ISL23318UFUZ-TK is packaged in a 10-lead UTQFN (2.1mm × 1.6mm, 0.5mm pitch), RoHS-compliant, with wettable flanks. Pinout matches the ISL23318WFRUZ series and is validated per Renesas FN7887 Rev 1.00.

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 ISL23318UFUZ-TK uniquely combines 1.2V I²C compatibility, volatile fast-write operation, and guaranteed monotonicity - making it optimal for battery-powered systems needing frequent, glitch-free wiper updates without EEPROM endurance concerns.

Availability

ISL23318UFUZ-TK is available at Aetrix Electronics and suitable for gain control in portable instrumentation, sensor trimming in automotive ECUs, and power supply margining in telecom infrastructure requiring stable component supply across extended temperature and voltage ranges.

Supply support for ISL23318UFUZ-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 is a global semiconductor leader delivering microcontrollers, analog power, and connectivity solutions for automotive, industrial, and IoT applications.

The ISL23318 product line delivers precision, low-power digitally controlled potentiometers optimized for battery-operated equipment and mixed-voltage systems where independent logic/analog supplies and wide temperature operation are critical.

FAQ

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

The ISL23318UFUZ-TK powers up with its volatile Wiper Register (WR) preset to 0x40 (decimal 64), placing the wiper at mid-scale - exactly halfway between RL and RH. This behavior is guaranteed across all operating conditions and eliminates undefined output states during system startup, ensuring predictable initial gain or bias settings in the ISL23318UFUZ-TK.

Does the ISL23318UFUZ-TK support I²C communication below 1.8V logic levels?

Yes, the ISL23318UFUZ-TK supports I²C operation down to 1.2V via its dedicated VLOGIC pin, which accepts 1.2V to 5.5V. This allows direct interface with ultra-low-voltage microcontrollers (e.g., ARM Cortex-M0+ at 1.2V I/O) without external level shifters - a key differentiator confirmed in the FN7887 datasheet for the ISL23318UFUZ-TK.

What happens to the wiper position when the ISL23318UFUZ-TK enters shutdown mode?

In shutdown mode (SHDN bit = 0 in Access Control Register), the ISL23318UFUZ-TK opens the RH–RL path and internally shorts RW to RL through a ~2kΩ resistor. Crucially, the current wiper register value is retained, so upon exit from shutdown, the ISL23318UFUZ-TK restores the exact prior tap position after a 1.5µs recall time - preserving calibration state.

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

Yes, the ISL23318UFUZ-TK supports rheostat mode (RW–RL or RW–RH). In this mode, it achieves ±0.15 MI differential nonlinearity and <1.0 MI zero-scale error (10kΩ option, VCC ≥2.7V), with wiper resistance remaining 70Ω typical. These values ensure accurate programmable current limiting or bias adjustment - verified in Table "RHEOSTAT MODE" of the ISL23318UFUZ-TK datasheet.

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

Up to four ISL23318UFUZ-TK devices can share one I²C bus using hardwired A0 and A1 pins, which set the two LSBs of the 7-bit slave address. With A0/A1 combinations (00, 01, 10, 11), addresses 0x28–0x2B are assigned - enabling compact multi-channel trimming without address conflicts in the ISL23318UFUZ-TK design.