Renesas ISL23315WFUZ-T7A

Overview

ISL23315WFUZ-T7A from Renesas Electronics is a volatile, low-voltage, 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 - used for precision bias compensation in RF power amplifiers and laser diodes.

For engineers reviewing the ISL23315WFUZ-T7A datasheet, ISL23315WFUZ-T7A pinout, ISL23315WFUZ-T7A application, or ISL23315WFUZ-T7A equivalent, key selection criteria include wiper settling time (0.4 µs), shutdown mode behavior (RW shorted to RL), ratiometric tempco (8 ppm/°C), and dual-supply independence enabling direct interfacing with 1.2V logic without level shifters.

Technical Context

The ISL23315WFUZ-T7A implements a monolithic CMOS resistor ladder with CMOS wiper switches operating in "make-before-break" mode, controlled via an 8-bit volatile Wiper Register (WR) accessible over I²C. Its architecture supports both voltage divider and rheostat configurations with guaranteed monotonicity.

It features independent analog (VCC) and logic (VLOGIC) supplies, allowing simultaneous operation at 1.7V analog and 1.2V digital rails. The device powers up to mid-scale (WR = 128), includes a dedicated Shutdown bit in the Access Control Register (ACR), and maintains WR state during shutdown while forcing RW–RL connection via ~2 kΩ internal path.

Key Specifications

Pinout & Package

ISL23315WFUZ-T7A is housed in a Pb-free, RoHS-compliant 10-lead µTQFN package (2.1 mm × 1.6 mm, 0.5 mm pitch), optimized for space-constrained PCB layouts in portable and automotive modules.

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 ISL23315WFUZ-T7A uniquely combines 1.2V I²C compatibility, 0.4 µs wiper settling, and 8 ppm/°C ratiometric tempco - making it optimal for fast, precision, low-power bias control where volatile operation is acceptable and logic/analog supply separation is critical.

Availability

ISL23315WFUZ-T7A is available at Aetrix Electronics and suitable for RF power amplifier bias compensation, laser diode bias compensation, and LCD bias compensation requiring stable component supply across extended temperature ranges and low-voltage logic interfaces.

Supply support for ISL23315WFUZ-T7A 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 SoC solutions for automotive, industrial, infrastructure, and IoT markets.

The ISL23315WFUZ-T7A belongs to Renesas' XDCP™ (eXternally Digital Controlled Potentiometer) family, engineered for high-accuracy, low-noise, and low-power analog trimming in battery-operated and thermally demanding systems.

FAQ

What is the default wiper position of the ISL23315WFUZ-T7A at power-on?

The ISL23315WFUZ-T7A powers up with its volatile Wiper Register (WR) preset to 128 (mid-scale, 0x80 hex), placing the RW terminal at the center of the 10 kΩ resistor ladder between RH and RL. This ensures a known, safe startup state for bias networks and eliminates risk of overvoltage transients in sensitive analog circuits. The ISL23315WFUZ-T7A maintains this behavior regardless of VCC or VLOGIC ramp sequence.

Does the ISL23315WFUZ-T7A support true 1.2V I²C bus operation?

Yes, the ISL23315WFUZ-T7A supports full I²C functionality down to 1.2V on the VLOGIC pin, including valid VIH/VIL thresholds, VOL, and timing compliance at 400 kHz. Its integrated level shifter eliminates external translation components - enabling direct connection to 1.2V/1.8V microcontrollers. The ISL23315WFUZ-T7A achieves this while maintaining separate 1.7V–5.5V VCC for analog performance.

How does shutdown mode affect the wiper and terminals of the ISL23315WFUZ-T7A?

In shutdown mode (SHDN bit = 0 in ACR), the ISL23315WFUZ-T7A forces an end-to-end open circuit between RH and RL while internally shorting RW to RL through a ~2 kΩ resistor. The wiper register value is retained, and upon exit from shutdown, the wiper returns to its prior position after 1.5 µs recall time. The ISL23315WFUZ-T7A draws <2.8 µA total supply current in this state.

What is the maximum recommended wiper current for the ISL23315WFUZ-T7A?

The ISL23315WFUZ-T7A specifies a maximum continuous wiper current of ±3 mA under recommended operating conditions. Exceeding this may cause localized heating, increased wiper resistance drift, or accelerated wear in long-term applications. For pulsed operation, the absolute maximum rating allows ±6 mA for ≤10 seconds - but sustained use above ±3 mA is not advised. The ISL23315WFUZ-T7A's 70 Ω typical wiper resistance at 3.3V further constrains practical current limits in voltage-divider configurations.

Can the ISL23315WFUZ-T7A be used in rheostat mode, and what are the linearity specifications?

Yes, the ISL23315WFUZ-T7A supports rheostat mode (RW–RL or RW–RH) with guaranteed monotonicity and RINL of ±1 MI (minimum increment) for the 10 kΩ version. Differential nonlinearity (RDNL) is ±0.4 MI, and offset error (Roffset) is ≤5.5 MI at 2.7–5.5V VCC. These specs ensure predictable, repeatable resistance adjustment in current-setting and gain-control applications. The ISL23315WFUZ-T7A maintains these values across its full -40°C to +125°C operating range.