Renesas ISL23415TFUZ

Overview

ISL23415TFUZ from Renesas Electronics is a volatile, low-voltage, SPI-controlled 256-tap digitally controlled potentiometer (DCP) in a 10-lead MSOP package, with 100kΩ end-to-end resistance, ±0.5 LSB integral nonlinearity, and operation from 1.7V VCC / 1.2V VLOGIC - used for precision bias compensation in RF power amplifiers and LCD voltage trimming.

For engineers reviewing the ISL23415TFUZ datasheet, ISL23415TFUZ pinout, ISL23415TFUZ application, or ISL23415TFUZ equivalent, this page delivers verified electrical specs, wiper settling time (3.5 µs), shutdown current (<2.8 µA), SPI timing compliance (5 MHz @ VLOGIC ≥ 1.7V), and real-world use cases in battery-powered medical calibration and power supply margining.

Technical Context

The ISL23415TFUZ implements a monolithic CMOS resistor ladder with CMOS wiper switches operating in "make-before-break" mode, directly controlled via an SPI Mode 0 interface. Its volatile Wiper Register (WR) defaults to 0x80 (mid-scale) at power-up and supports read/write access without external memory.

It features independent analog (VCC: 1.7–5.5V) and logic (VLOGIC: 1.2–5.5V) supplies, enabling direct interfacing with 1.2V microcontrollers without level shifters. Shutdown mode forces RH–RL open-circuit and shorts RW to RL via a 2kΩ internal resistor while preserving WR contents.

Key Specifications

Pinout & Package

ISL23415TFUZ is housed in a Pb-free, RoHS-compliant 10-lead MSOP package (M10.118), 3.0 mm × 3.0 mm × 1.0 mm, with exposed pad for thermal enhancement.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5175BRMZ-100 and MCP41HV51-104E/P, the ISL23415TFUZ uniquely combines 1.2V logic compatibility, ultra-low shutdown current, and guaranteed monotonicity - making it optimal for battery-constrained, thermally demanding, and mixed-voltage embedded systems.

Availability

ISL23415TFUZ is available at Aetrix Electronics and suitable for RF power amplifier bias compensation, LCD panel voltage trimming, portable medical sensor calibration, and power supply output margining requiring stable component supply across extended temperature ranges.

Supply support for ISL23415TFUZ 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 automotive, industrial, and IoT applications.

The ISL23415 product line delivers precision, low-power digitally controlled potentiometers targeting battery-operated equipment and systems requiring robust operation from -40°C to +125°C.

FAQ

What is the default wiper position of the ISL23415TFUZ at power-up?

The ISL23415TFUZ powers up with its volatile Wiper Register (WR) preset to 0x80 (128 decimal), placing the wiper at mid-scale - i.e., approximately 50 kΩ between RH and RW, and 50 kΩ between RW and RL. This behavior is guaranteed across all operating conditions and eliminates startup transients in voltage divider configurations. The ISL23415TFUZ does not retain wiper position across power cycles unless externally managed by the host controller.

Does the ISL23415TFUZ support daisy-chaining, and how many devices can be cascaded?

Yes, the ISL23415TFUZ supports SPI daisy-chaining: the SDO of one device connects to the SDI of the next, with shared CS and SCK lines. The number of cascaded ISL23415TFUZ units is limited only by the drive strength of the host MCU's SCK and CS pins - Renesas confirms reliable operation with ≥4 devices using standard GPIO drivers. Each device processes instructions in reverse order during write sequences, enabling simultaneous wiper updates.

What is the maximum allowable voltage on the RH, RL, or RW pins of the ISL23415TFUZ?

The absolute maximum voltage on any DCP terminal (RH, RL, or RW) is -0.3V to 6.0V, but operational limits require that all DCP pin voltages remain within 0V to VCC. Exceeding VCC risks latch-up or permanent damage. For example, with VCC = 3.3V, RH/RL/RW must stay between 0V and 3.3V - even during power-up sequencing. This constraint applies regardless of VLOGIC level and is strictly enforced in the ISL23415TFUZ's internal protection architecture.

How does the shutdown mode affect the ISL23415TFUZ's terminal connections?

In shutdown mode (SHDN bit = 0 in ACR), the ISL23415TFUZ internally opens the RH–RL path and connects RW to RL through a 2 kΩ series resistor. This isolates the wiper from the high-side terminal while maintaining a defined low-impedance path to ground - preventing floating nodes in bias circuits. Critically, the WR register contents are preserved, so wiper position is restored within 1.5 µs after shutdown release, with no host reprogramming required.

Can the ISL23415TFUZ operate with VLOGIC = 1.2V and VCC = 1.7V simultaneously?

Yes, the ISL23415TFUZ is fully specified to operate with VLOGIC = 1.2V and VCC = 1.7V concurrently. At these minimum rails, it maintains SPI functionality at 1 MHz clock rate, draws ≤30 µA VLOGIC supply current during active read/write, and achieves 3.5 µs wiper settling time in rheostat mode. This dual-rail capability is validated across -40°C to +125°C and enables direct integration with energy-harvesting and coin-cell-powered systems.