Renesas X9318WS8ZT1

Overview

X9318WS8ZT1 from Intersil is a digitally controlled potentiometer (XDCP™) implementing a 10 kΩ end-to-end resistance solid-state resistor array with 100 wiper tap points, nonvolatile wiper position storage, and 3-wire serial interface (CS/U/D/INC). It operates from 4.5–5.5 V, supports terminal voltages up to +8 V, and delivers ±1% absolute linearity for precision analog trimming in voltage regulator output control and laser diode bias circuits.

For engineers reviewing the X9318WS8ZT1 datasheet, X9318WS8ZT1 pinout, X9318WS8ZT1 application, or X9318WS8ZT1 equivalent, key selection criteria include its 100-year data retention, 100,000-cycle endurance, 40–200 Ω wiper resistance, ratiometric temperature coefficient of ±20 ppm/°C, and Pb-free 8-lead SOIC (150 mil) package compatibility with SnPb and Pb-free reflow.

Technical Context

The X9318WS8ZT1 integrates a 99-element resistor ladder, 7-bit up/down counter, "make-before-break" wiper switching network, and nonvolatile memory for power-up recall. Its control logic responds to negative-edge-triggered INC pulses while CS is low, with U/D determining direction-no clock or address bus required.

It functions as either a three-terminal voltage divider (RH/RW/RL) or two-terminal variable resistor (RW–RL or RW–RH), with wiper current limited to ±3 mA and terminal voltage range of 0 to +8 V referenced to VSS. The device exhibits ratiometric tracking across temperature due to matched resistor element TC and low 200 Ω max wiper resistance.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (150 mil), RoHS-compliant Pb-free with matte tin finish, MSL-1 rated for standard reflow profiles.

Key Features

Applications

Equivalent & Alternatives

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

Compared with X9318WS8ZT1, AD5243BRMZ10 offers dual-channel capability but looser RTOTAL tolerance and higher TC, while MCP41010-I/P provides SPI compatibility but lacks inherent power-up recall-requiring additional design effort for state retention.

Availability

X9318WS8ZT1 is available at Aetrix Electronics and suitable for LCD bias control, laser diode bias control, and voltage regulator output trim requiring stable component supply, long-term calibration integrity, and industrial temperature operation.

Supply support for X9318WS8ZT1 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 company specializing in precision analog, power management, and interface ICs for industrial, communications, and computing markets.

The X9318 family was designed as a solid-state replacement for mechanical potentiometers in analog trimming applications-emphasizing reliability, nonvolatile setting retention, and minimal system resource requirements.

FAQ

What is the operating temperature range for the X9318WS8ZT1?

The X9318WS8ZT1 is specified for operation from 0°C to +70°C ambient. This industrial-grade range supports use in consumer displays, embedded power supplies, and optical modules where extended thermal stability is required without automotive-grade qualification. The device's ratiometric temperature coefficient of ±20 ppm/°C ensures predictable performance across this full range.

Does the X9318WS8ZT1 require an external microcontroller to function?

No, the X9318WS8ZT1 operates autonomously using only three digital control lines (CS, U/D, INC) and does not require a microcontroller, clock source, or firmware. A simple push-button or logic circuit can directly drive the interface. However, if automatic calibration or remote adjustment is needed, an MCU may be used-but it is not mandatory for basic wiper positioning or nonvolatile recall.

How is wiper position stored and recalled in the X9318WS8ZT1?

Wiper position is stored in nonvolatile memory when CS is raised high while INC is held high-a hardware-only store command requiring no serial protocol or timing sequence. On power-up, the X9318WS8ZT1 automatically recalls the last stored value and configures the wiper to that tap position within 500 µs, ensuring repeatable analog settings without host intervention.

Can the X9318WS8ZT1 be used as a two-terminal variable resistor?

Yes, the X9318WS8ZT1 supports two-terminal operation by connecting either RH or RL to RW (or leaving one fixed terminal unconnected) to form a variable resistance between RW and the remaining terminal. This mode is commonly used for gain-setting or current-limiting applications where only resistance variation-not voltage division-is required.

What is the maximum allowable voltage across RH and RL terminals of the X9318WS8ZT1?

The X9318WS8ZT1 allows up to +8 V applied between RH and RL terminals with respect to VSS, as confirmed in the Absolute Maximum Ratings and Potentiometer Characteristics sections of the datasheet. Exceeding this voltage risks permanent damage to the resistor array or internal switches, and operation above 8 V is not guaranteed or characterized.