Renesas X9318WS8IZT1

Overview

X9318WS8IZT1 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 is used for precision DC bias adjustment in analog signal chains.

For engineers reviewing the X9318WS8IZT1 datasheet, X9318WS8IZT1 pinout, X9318WS8IZT1 application, or X9318WS8IZT1 equivalent, key selection criteria include wiper resolution (1% / 99-element array), nonvolatile recall on power-up, ±300 ppm/°C RTOTAL temperature coefficient, and SOIC-8 packaging with RoHS-compliant Pb-free finish.

Technical Context

The X9318WS8IZT1 integrates a 7-bit up/down counter, one-of-100 decoder, and nonvolatile memory to control wiper position across 99 resistive elements. Its "make-before-break" switching ensures continuity during tap transitions, avoiding open-circuit interruptions in voltage divider or variable-resistor configurations.

Control logic responds to negative-edge-triggered INC pulses while CS is low; U/D sets direction. Wiper position is stored to nonvolatile memory only when CS rises high with INC held high - a deliberate store command distinct from standby entry.

Key Specifications

Pinout & Package

Package: 8-lead SOIC (150 mil width), RoHS-compliant Pb-free finish, JEDEC MS-012AC standard footprint.

Key Features

Applications

Equivalent & Alternatives

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

Compared with X9318WS8IZT1, AD5241BRMZ10 offers finer resolution but lacks guaranteed 100-year data retention and uses a different serial protocol; MCP41010-I/P provides SPI compatibility but forfeits persistent power-up state - making X9318WS8IZT1 optimal for unattended, calibration-critical industrial systems.

Availability

X9318WS8IZT1 is available at Aetrix Electronics and suitable for LCD bias control, laser diode biasing, and voltage regulator output trimming requiring stable component supply, long-term calibration integrity, and industrial temperature operation.

Supply support for X9318WS8IZT1 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 U.S.-based semiconductor company specializing in precision analog, power management, and interface ICs for industrial, computing, and communications markets.

The X9318 product line delivers digitally programmable resistance with nonvolatile memory for applications demanding repeatable, maintenance-free analog trimming - targeting instrumentation, optical modules, and industrial control systems.

FAQ

What is the maximum voltage that can be applied across RH and RL terminals of the X9318WS8IZT1?

The X9318WS8IZT1 supports a terminal voltage of 0 to +8 V between RH and RL, referenced to VSS. This rating is specified under absolute maximum conditions and applies across the full operating temperature range. Exceeding +8 V risks permanent damage to the internal resistor array and switching network. The device is not rated for AC or reverse-biased operation beyond this limit.

Does the X9318WS8IZT1 retain its wiper position after power cycling?

Yes, the X9318WS8IZT1 stores the wiper position in nonvolatile memory and automatically recalls it on power-up. This behavior is guaranteed for 100 years under normal operating conditions. The wiper position is only updated in nonvolatile memory when CS transitions high while INC is held high - a deliberate store command - ensuring robustness against accidental writes during transient conditions.

What is the wiper resistance specification for the X9318WS8IZT1, and how does it affect circuit performance?

The X9318WS8IZT1 specifies wiper resistance as 40 Ω typical and 200 Ω maximum at 1 mA test current. This series resistance introduces a small but measurable error in low-voltage or high-precision applications - for example, causing ~0.2% gain error in a 10 kΩ feedback divider. Designers should account for it in error budgets, especially when RW drives high-impedance nodes or when used in current-sensing paths.

Can the X9318WS8IZT1 be used in a two-terminal variable resistor configuration?

Yes, the X9318WS8IZT1 supports two-terminal operation by connecting either RH or RL to RW and using the remaining fixed terminal with RW as the variable resistance element. In this mode, the effective resistance ranges from near 0 Ω (wiper at same terminal) to RTOTAL (wiper at opposite end). The device's make-before-break switching prevents open-circuit states, making it suitable for laser diode bias and other current-control applications.

Is the X9318WS8IZT1 RoHS compliant, and what does the 'Z' suffix indicate in its part number?

Yes, the X9318WS8IZT1 is RoHS compliant. The 'Z' suffix denotes Pb-free plus anneal construction - using 100% matte tin termination finish and RoHS-compliant molding compounds. This ensures compatibility with both SnPb and lead-free soldering processes and meets IPC/JEDEC J-STD-020 reflow requirements. The 'I' indicates −40°C to +85°C industrial temperature grade, and 'T1' specifies tape-and-reel packaging.