Renesas ISL23318TFUZ

Overview

ISL23318TFUZ from Renesas Electronics is a volatile, low-voltage, I²C-controlled 128-tap digital potentiometer with 100kΩ end-to-end 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 functions as a precision three-terminal potentiometer or two-terminal rheostat in voltage divider and bias adjustment circuits for battery-powered instrumentation.

For engineers reviewing the ISL23318TFUZ datasheet, ISL23318TFUZ pinout, ISL23318TFUZ application, or ISL23318TFUZ equivalent, key selection criteria include its dual-supply I²C interface (independent VLOGIC), mid-scale power-on default (64), shutdown mode with internal RW–RL short, ±0.15 LSB integral nonlinearity, and -40°C to +125°C extended industrial temperature range.

Technical Context

The ISL23318TFUZ implements a monolithic CMOS resistor ladder with CMOS wiper switches and integrated I²C interface logic, supporting make-before-break wiper transitions and direct volatile Wiper Register (WR) read/write. Its architecture enables precise, noise-immune analog tuning without external level shifters across mixed-voltage systems.

It features independent VLOGIC and VCC supplies, allowing 1.2V I²C bus operation while powering the DCP core at up to 5.5V; shutdown mode forces RH–RL open-circuit and internally shorts RW to RL via ~2kΩ, preserving WR contents. Power-on reset initializes WR to 64 (mid-scale), ensuring deterministic startup behavior.

Key Specifications

Pinout & Package

ISL23318TFUZ is packaged in a Pb-free, RoHS-compliant 10-lead MSOP (M10.118) with exposed pad thermal performance optimized for surface-mount assembly in space-constrained applications.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5170BRMZ-100 and MCP45HV51-103E/MS, ISL23318TFUZ uniquely supports 1.2V I²C operation with independent VLOGIC, making it optimal for mixed-supply systems where logic and analog domains operate at different voltages - a capability neither alternative provides.

Availability

ISL23318TFUZ is available at Aetrix Electronics and suitable for gain adjustment in battery-powered instruments, trimming sensor circuits, power supply margining, RF power amplifier bias compensation, and other precision analog tuning applications requiring stable component supply across automotive, industrial, and medical device programs.

Supply support for ISL23318TFUZ 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, including high-performance analog, power management, and timing products for automotive, industrial, and IoT markets.

The ISL23318 belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) family, engineered specifically for precision, low-power, mixed-voltage analog tuning in battery-operated and thermally demanding systems.

FAQ

What is the default wiper position of the ISL23318TFUZ at power-on?

The ISL23318TFUZ initializes its volatile Wiper Register (WR) to 64 (hex 40h) at power-on, placing the wiper at mid-scale - exactly halfway between RH and RL terminals. This deterministic startup behavior ensures predictable initial gain or bias settings in feedback loops and eliminates undefined output states during system boot.

Does the ISL23318TFUZ require an external level shifter for 1.2V I²C communication?

No, the ISL23318TFUZ does not require an external level shifter for 1.2V I²C communication because it features a dedicated VLOGIC pin that accepts 1.2V to 5.5V logic supply independently of VCC. This built-in level translation allows direct connection to 1.2V, 1.8V, or 3.3V microcontrollers without additional components.

Can the ISL23318TFUZ be used as a two-terminal variable resistor?

Yes, the ISL23318TFUZ can be configured as a two-terminal variable resistor (rheostat) by connecting either RH or RL to the same node as RW and leaving the unused terminal unconnected. In this mode, resistance between RW and the connected terminal varies from near-zero to 100kΩ with ±0.15 LSB integral nonlinearity.

What happens to the wiper setting during ISL23318TFUZ shutdown mode?

During shutdown mode (activated by setting SHDN bit in Access Control Register), the ISL23318TFUZ preserves its current wiper setting in the volatile WR register. The RH–RL path opens, and RW is internally shorted to RL via ~2kΩ. Upon exit from shutdown, the wiper returns to its pre-shutdown position after a 1.5µs recall time.

Is the ISL23318TFUZ compatible with standard I²C bus speeds?

Yes, the ISL23318TFUZ supports standard-mode I²C operation up to 400kHz, meeting JEDEC and NXP I²C specifications. Its SDA/SCL timing parameters - including tLOW (1300ns min), tHIGH (600ns min), and tBUF (1300ns min) - ensure reliable communication with common microcontroller I²C peripherals without bus contention or timing violations.