Renesas ISL90810WIU8Z-TK

Overview

ISL90810WIU8Z-TK from Intersil is a single-channel, digitally controlled potentiometer (XDCP™) with 256 taps, I²C interface, 10kΩ total resistance, 70Ω typical wiper resistance at 3.3V, and operates from 2.7V to 5.5V supply. It functions as a precision voltage divider or rheostat in analog signal conditioning circuits requiring stable, programmable gain or offset adjustment.

For engineers reviewing the ISL90810WIU8Z-TK datasheet, ISL90810WIU8Z-TK pinout, ISL90810WIU8Z-TK application, or ISL90810WIU8Z-TK equivalent, this device supports mid-scale power-on default (128), ±0.5 LSB DNL (U-grade), ratiometric temperature coefficient of ±4 ppm/°C, and low 5µA max standby current - critical for battery-powered sensor interfaces and calibration subsystems.

Technical Context

The ISL90810WIU8Z-TK implements a monolithic CMOS resistor ladder with CMOS switch matrix controlled by an 8-bit volatile Wiper Register (WR), directly accessible via I²C. Its wiper position is updated within 1 µs after SCL falling edge, enabling fast digital trimming in closed-loop systems.

It operates in two primary modes: voltage divider (RH–RL terminals biased at VCC/GND, RW output tapped) and rheostat (RW–RL or RW–RH used as variable resistor). The device features ±3.0mA wiper current rating, 10pF terminal capacitance (CH/CL), and 25pF wiper capacitance (CW), supporting bandwidth up to 2.2MHz per Figure 12.

Key Specifications

Pinout & Package

ISL90810WIU8Z-TK is housed in an 8-lead MSOP package (JEDEC MO-187-AA compliant, 3.0mm × 3.0mm body, 0.65mm pitch), RoHS-compliant with matte tin termination.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5170BRMZ-10 and MCP4017T-103I/OT, the ISL90810WIU8Z-TK delivers superior ratiometric stability (±4 ppm/°C vs. 15/- ppm/°C), lower wiper resistance (70Ω vs. 100Ω), and deterministic mid-scale power-on behavior - making it preferred for industrial calibration and precision analog control where repeatability and startup safety are mandatory.

Availability

ISL90810WIU8Z-TK is available at Aetrix Electronics and suitable for industrial sensor calibration, laser diode biasing, programmable gain amplification, and audio channel balancing requiring stable component supply and long-term obsolescence management.

Supply support for ISL90810WIU8Z-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

Intersil Corporation (now part of Renesas Electronics) designs high-performance analog and power management ICs, emphasizing precision, low noise, and robust industrial qualification.

The ISL90810WIU8Z-TK belongs to Intersil's XDCP™ family of digitally controlled potentiometers, engineered specifically for replacing mechanical trimpots in automated test equipment, medical instrumentation, and industrial control systems where reliability and programmability are essential.

FAQ

What is the power-on behavior of the ISL90810WIU8Z-TK?

The ISL90810WIU8Z-TK initializes its wiper to tap position 128 (mid-scale, 0x80 hex) upon power-up, ensuring a known, repeatable starting point for analog circuits. This behavior is hardwired and does not require I²C initialization, eliminating output glitches during cold start in systems like sensor front-ends or bias networks where uncontrolled startup voltage could damage downstream components.

Can the ISL90810WIU8Z-TK operate as a two-terminal variable resistor?

Yes, the ISL90810WIU8Z-TK supports rheostat mode by connecting either RH or RL to RW and leaving the unused terminal open. In this configuration, it functions as a digitally adjustable resistor between RW and the connected terminal, with 10kΩ maximum resistance and ±3.0mA wiper current rating - suitable for LED current limiting or oscillator frequency tuning where three-terminal divider operation is unnecessary.

What is the maximum operating frequency for analog signals applied to the ISL90810WIU8Z-TK?

Per Figure 12 in the FN8234 datasheet, the ISL90810WIU8Z-TK maintains usable performance up to 2.2MHz in small-signal conditions. This bandwidth is enabled by low terminal capacitances (CH = CL = 10pF, CW = 25pF) and low wiper resistance (70Ω typical), making it viable for audio band and medium-speed control loop applications - though large-signal settling (Figure 14) shows ~1µs stabilization after wiper movement.

Does the ISL90810WIU8Z-TK retain wiper position after power cycling?

No, the ISL90810WIU8Z-TK uses a volatile wiper register only; wiper position is lost when VCC is removed. It resets to tap 128 on each power-up. For non-volatile storage, external microcontroller firmware must reprogram the desired tap value after boot - a deliberate design choice to ensure deterministic startup and avoid stale settings from prior sessions.

How does the ISL90810WIU8Z-TK handle I²C bus contention or incomplete transactions?

The ISL90810WIU8Z-TK requires a valid START condition followed by correct identification byte (0x50/0x51) and address byte (0x00) before accepting writes or initiating reads. Invalid sequences - including missing ACKs, incorrect addresses, or truncated clocks - are ignored, and the device remains in standby. This prevents unintended wiper changes during noisy bus conditions or partial firmware writes.