Renesas ISL23445WFVZ-T7A

Overview

ISL23445WFVZ-T7A from Renesas Electronics (formerly Intersil) is a volatile quad digitally controlled potentiometer (DCP) with 256-tap resolution, SPI interface, and 10kΩ end-to-end resistance per channel. It operates from 1.7V to 5.5V VCC and 1.2V to 5.5V VLOGIC, features 70Ω typical wiper resistance at 3.3V, and supports -40°C to +125°C industrial temperature range. It is used for precision gain adjustment in battery-powered instrumentation.

For engineers reviewing the ISL23445WFVZ-T7A datasheet, ISL23445WFVZ-T7A pinout, ISL23445WFVZ-T7A application, or ISL23445WFVZ-T7A equivalent, key selection considerations include its 10kΩ resistance option, TSSOP-20 package, SPI daisy-chain capability, shutdown mode behavior, and mid-scale power-on default for deterministic startup.

Technical Context

The ISL23445WFVZ-T7A integrates four independent DCP cores on a monolithic CMOS IC, each with an 8-bit volatile Wiper Register (WRi) directly accessible via SPI Mode 0 (CPOL=0, CPHA=0). Wiper positioning uses make-before-break switching, ensuring glitch-free transitions between taps.

It implements dual-supply architecture: VCC powers analog resistor arrays and wiper switches (1.7V–5.5V), while VLOGIC independently supplies logic and SPI interface (1.2V–5.5V), enabling direct interfacing with low-voltage microcontrollers without level shifters. Shutdown mode forces open-circuit end-to-end and internally connects RWi to RLi through a 2kΩ resistor.

Key Specifications

Pinout & Package

ISL23445WFVZ-T7A is packaged in a Pb-free 20-lead TSSOP (MDP0044), 6.5mm × 4.4mm, 0.65mm pitch. Pin functions are validated per FN7874 Rev 0.00 datasheet, Page 3 (Pin Configurations) and Page 4 (Pin Descriptions).

Key Features

Applications

Equivalent & Alternatives

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

Compared with ISL23445WFVZ-T7A, ISL23425WFVZ-T7A offers identical per-channel performance in a smaller footprint but lacks multi-channel integration, while AD5242BRUZ10 trades SPI flexibility and VLOGIC independence for simpler two-wire control-neither is pin-compatible, and all require layout adaptation.

Availability

ISL23445WFVZ-T7A is available at Aetrix Electronics and suitable for power supply margining, RF amplifier bias compensation, and sensor trimming applications requiring stable component supply across extended temperature and low-voltage operating conditions.

Supply support for ISL23445WFVZ-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 Corporation is a global semiconductor leader delivering trusted embedded design innovation, with origins in Intersil's precision analog portfolio acquired in 2017.

The ISL23445WFVZ-T7A belongs to Renesas' XDCP™ family of digitally controlled potentiometers, engineered for high-reliability analog tuning in battery-constrained, thermally demanding, and mixed-voltage systems.

FAQ

What is the resistance tolerance and temperature coefficient of the ISL23445WFVZ-T7A?

The ISL23445WFVZ-T7A has a ±2% end-to-end resistance tolerance and a 125 ppm/°C end-to-end temperature coefficient (TCR), specified for the 10kΩ option across -40°C to +125°C. These values ensure predictable voltage division accuracy in thermal cycling environments such as automotive engine control units or industrial motor drives where ambient temperature varies widely.

Does the ISL23445WFVZ-T7A retain wiper settings after power cycle?

No, the ISL23445WFVZ-T7A uses volatile Wiper Registers (WR0–WR3); all wiper positions reset to mid-scale (128) on power-up. To restore custom settings, the host MCU must reinitialize the registers via SPI after each power-on sequence. This behavior is inherent to the device architecture and cannot be altered by configuration bits.

Can the ISL23445WFVZ-T7A operate with VLOGIC = 1.2V and VCC = 5.5V simultaneously?

Yes, the ISL23445WFVZ-T7A fully supports independent VLOGIC and VCC supplies: VLOGIC may be as low as 1.2V while VCC runs up to 5.5V. This allows direct connection to 1.2V FPGA I/O banks or ultra-low-power MCUs while powering analog circuits from a higher-voltage rail-eliminating level-shifting components and reducing bill-of-materials cost.

What is the maximum SPI clock frequency supported by the ISL23445WFVZ-T7A at 1.2V VLOGIC?

At VLOGIC = 1.2V, the ISL23445WFVZ-T7A supports a maximum SCK frequency of 1 MHz. This is specified in the Serial Interface section (Page 7) of FN7874 Rev 0.00. Higher frequencies (up to 5 MHz) are permitted only when VLOGIC ≥ 1.7V. System firmware must dynamically scale clock rate based on applied VLOGIC voltage.

How does shutdown mode affect the ISL23445WFVZ-T7A's wiper terminals?

In shutdown mode (SHDN bit = 0 in ACR), each DCP channel is forced into an end-to-end open circuit (RH–RL disconnected), and each RWi terminal is internally connected to its corresponding RLi terminal through a 2kΩ resistor. This isolates the DCP from external circuitry while preserving WRi register contents, allowing immediate resumption of prior settings upon exit from shutdown.