Renesas X9318WS8

Overview

X9318WS8 from Intersil is a digitally controlled potentiometer (XDCP™) with 100 wiper tap points, 10 kΩ end-to-end resistance, and nonvolatile wiper position storage. It operates from 4.5 V to 5.5 V, supports 0–8 V terminal voltage, and functions as a three-terminal voltage divider or two-terminal variable resistor in analog trim applications.

For engineers reviewing the X9318WS8 datasheet, X9318WS8 pinout, X9318WS8 application, or X9318WS8 equivalent, this device is selected for precision DC bias adjustment, LCD panel voltage control, laser diode current regulation, and programmable voltage regulator feedback networks where power-up repeatability and solid-state reliability are required.

Technical Context

The X9318WS8 implements a 99-element resistor array with make-before-break wiper switching, enabling glitch-free tap transitions. Its 7-bit up/down counter drives a one-of-100 decoder to select wiper position, with CS/INC/U/D forming a synchronous 3-wire serial interface.

Wiper position is stored into nonvolatile memory on CS↑ while INC = HIGH, retaining settings for ≥100 years. The device exhibits ±300 ppm/°C RTOTAL temperature coefficient and ratiometric tracking of ±20 ppm/°C, ensuring stable voltage division across temperature.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (150 mil), RoHS-compliant Pb-free finish (X9318WS8Z variant).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5243BRMZ10 and MCP41010-I/P, the X9318WS8 provides guaranteed power-up repeatability without firmware intervention, deterministic 3-wire timing, and tighter ratiometric temperature tracking-making it optimal for safety-critical or maintenance-free analog trim.

Availability

X9318WS8 is available at Aetrix Electronics and suitable for LCD bias control, laser diode current regulation, and voltage regulator output trim requiring stable component supply, long-term calibration retention, and RoHS-compliant packaging.

Supply support for X9318WS8 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) is a semiconductor manufacturer specializing in high-performance analog and mixed-signal ICs for power management, precision analog, and interface applications.

The X9318WS8 belongs to Intersil's XDCP™ family of digitally controlled potentiometers, designed specifically for replacing mechanical trimmers in industrial, medical, and telecom equipment where long-term stability and digital configurability are essential.

FAQ

What is the maximum allowable voltage across RH and RL terminals of the X9318WS8?

The X9318WS8 supports a terminal voltage range of 0 V to +8 V across RH and RL, independent of VCC. This allows use in bias networks exceeding the 5 V supply rail-such as LCD VCOM lines or laser diode anode supplies-without damage or performance degradation, provided absolute maximum ratings (≤+10 V) are respected.

Does the X9318WS8 retain its wiper position after power cycling?

Yes, the X9318WS8 stores wiper position in nonvolatile memory and automatically recalls it on power-up. This behavior is guaranteed for ≥100 years under normal operating conditions. No external components or firmware initialization are needed-the X9318WS8 resumes operation at the last stored tap position immediately after VCC stabilizes.

Can the X9318WS8 be used as a two-terminal variable resistor?

Yes, the X9318WS8 can operate as a two-terminal variable resistor by connecting either RH or RL to RW and using the remaining fixed terminal with RW. In this configuration, resistance varies from near 0 Ω (wiper at terminal) to RTOTAL (wiper at opposite end), enabling current-setting applications like LED bias or sensor excitation-while maintaining the same 100-step resolution and nonvolatile storage.

What is the recommended power-up sequence for reliable operation of the X9318WS8?

Apply VCC and VSS first, then any external voltages on RH, RL, or RW. Wait ≥1 ms after VCC reaches final value before asserting CS or toggling INC. To prevent unintended wiper movement or store operations, hold CS and INC HIGH until VCC is stable. This sequence ensures internal logic resets correctly and avoids spurious edges during supply ramp.

How does the X9318WS8 handle wiper movement across multiple taps?

The X9318WS8 uses make-before-break switching: when moving multiple positions, intermediate taps connect briefly to RW before final position settles. This prevents open-circuit transients but may temporarily reduce effective RTOTAL. For critical feedback paths, limit multi-step moves to ≤3 taps per command or insert ≥500 µs delay between INC pulses to ensure stable settling per tIW specification.