Renesas ISL23425TFRUZ-TK

Overview

ISL23425TFRUZ-TK from Renesas Electronics (formerly Intersil) is a dual, volatile, 256-tap digitally controlled potentiometer (DCP) with SPI interface, 100kΩ total resistance, 1.7V–5.5V analog supply (VCC), 1.2V–5.5V logic supply (VLOGIC), and -40°C to +125°C operation. It serves as programmable voltage divider or rheostat in precision analog trimming circuits for battery-powered instrumentation.

For engineers reviewing the ISL23425TFRUZ-TK datasheet, ISL23425TFRUZ-TK pinout, ISL23425TFRUZ-TK application, or ISL23425TFRUZ-TK equivalent, key selection criteria include dual-channel wiper register control, shutdown mode with end-to-end open circuit, low 70Ω typical wiper resistance at 3.3V, daisy-chain SPI capability, and µTQFN-16 package compatibility with space-constrained industrial designs.

Technical Context

The ISL23425TFRUZ-TK integrates two independent DCP cores on a monolithic CMOS die, each with an 8-bit volatile Wiper Register (WR0/WR1) directly accessible via SPI Mode 0. Wiper positioning uses make-before-break switching, ensuring monotonic resistance transitions and glitch-free operation during tap changes.

Its dual-supply architecture separates analog (VCC) and digital (VLOGIC) domains, enabling direct interfacing with 1.2V microcontrollers without level shifters. Shutdown mode disconnects resistor arrays and internally connects each RW to RL via a 2kΩ path, reducing system power leakage while preserving WR values.

Key Specifications

Pinout & Package

ISL23425TFRUZ-TK is packaged in a 16-lead 2.6mm × 1.8mm µTQFN (L16.2.6x1.8A), RoHS-compliant, with exposed thermal pad. Pin 1 marked by dot; pin 1 location confirmed per datasheet top view.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5242BRUZ100 and MCP42100-E/ST, the ISL23425TFRUZ-TK uniquely combines dual-channel operation, 1.2V logic compatibility, shutdown-mode safety, and guaranteed monotonicity down to 1.7V-making it optimal for compact, multi-rail industrial and battery-powered systems requiring coordinated analog trimming.

Availability

ISL23425TFRUZ-TK is available at Aetrix Electronics and suitable for power supply margining, RF amplifier biasing, sensor trimming, and portable instrumentation requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ISL23425TFRUZ-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 Corporation is a global semiconductor leader delivering trusted embedded design innovation, with origins in Intersil's precision analog portfolio acquired in 2017.

The ISL23425 series belongs to Renesas' XDCP™ (eXternally Digitally Controlled Potentiometer) product line, engineered specifically for high-accuracy, low-power, and thermally robust analog trimming in automotive, industrial, and medical equipment.

FAQ

What is the default wiper position of the ISL23425TFRUZ-TK at power-up?

At power-up, both wiper registers (WR0 and WR1) of the ISL23425TFRUZ-TK reset to 0x80 (128 decimal), positioning each wiper at mid-scale-exactly halfway between RH and RL terminals. This ensures predictable, safe startup behavior in voltage divider configurations and avoids transient overvoltage or undervoltage conditions in sensitive analog circuits.

Does the ISL23425TFRUZ-TK support daisy-chaining with other DCPs on the same SPI bus?

Yes, the ISL23425TFRUZ-TK supports daisy-chaining via its SDO pin, which can be configured as push-pull or open-drain output. When configured for open-drain operation (via ACR[1]), multiple ISL23425TFRUZ-TK devices can share a single SDO line, enabling sequential readback of wiper positions without additional GPIOs or bus arbitration logic.

What is the maximum SPI clock frequency supported by the ISL23425TFRUZ-TK at 1.2V VLOGIC?

At VLOGIC = 1.2V, the ISL23425TFRUZ-TK supports a maximum SCK frequency of 1MHz. This is specified in the Serial Interface Specification section (Page 7) and reflects timing constraints imposed by lower-voltage logic thresholds. For higher throughput, operate VLOGIC ≥ 1.7V to enable the full 5MHz SCK rate.

How does the shutdown mode affect the wiper registers and terminal connections in the ISL23425TFRUZ-TK?

In shutdown mode (SHDN bit = 0 in ACR), the ISL23425TFRUZ-TK forces each DCP into an end-to-end open circuit between RH and RL, while internally connecting each RW to its corresponding RL via a 2kΩ resistor. Critically, the WR0 and WR1 register contents are preserved, and wipers return to their pre-shutdown positions within 1.5µs after SHDN deactivation.

Is the ISL23425TFRUZ-TK pin-compatible with other variants in the ISL23425 family, such as ISL23425TFRUZ-T7A?

Yes, the ISL23425TFRUZ-TK is pin-compatible with ISL23425TFRUZ-T7A and all other 16-lead µTQFN variants of the ISL23425 family. Both share identical pinout, package dimensions (2.6mm × 1.8mm), thermal pad layout, and electrical specifications-the only difference is tape-and-reel packaging quantity (1k vs 250 units).