Renesas X9279UV14Z

Overview

X9279UV14Z from Intersil is a single-channel, 256-tap, digitally controlled potentiometer (XDCP™) with 50kΩ end-to-end resistance, 2-wire serial interface, and non-volatile data registers. It operates from 2.7V to 5.5V, features <5µA standby current, and is used for precision analog trimming in voltage regulators, sensor signal conditioning, and audio gain control.

For engineers reviewing the X9279UV14Z datasheet, X9279UV14Z pinout, X9279UV14Z application, or X9279UV14Z equivalent, this page delivers verified technical context, real-world design meaning of key specs, validated pin functions, and two confirmed alternative parts for parameter-matched digital potentiometer replacement.

Technical Context

The X9279UV14Z implements a monolithic CMOS resistor array of 255 segments with CMOS-switched wiper selection controlled by an 8-bit volatile Wiper Counter Register (WCR). Its 2-wire bus supports read/write/transfer operations to four non-volatile data registers (DR0–DR3), with power-up recall loading DR0 into the WCR.

Hardware write protection via the WP pin disables non-volatile writes; address pins A0–A2 allow up to eight devices on one bus, while A3 must be grounded. The device supports increment/decrement mode for fine wiper adjustment via SCL clocking with SDA held high/low.

Key Specifications

Pinout & Package

Package: 14-lead TSSOP (4.4mm width), Pb-free (RoHS compliant), moisture sensitivity level (MSL) rated per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

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

Compared with X9279UV14Z, ISL95810 omits hardware write protection-reducing fault tolerance in field-updatable systems-while AD5170BRMZ-50 offers identical resistance and resolution but requires PCB rework due to pin count and package mismatch.

Availability

X9279UV14Z is available at Aetrix Electronics and suitable for voltage regulator trimming, sensor calibration, audio gain control, and LCD contrast adjustment requiring stable component supply across industrial and commercial temperature ranges (0°C to +70°C).

Supply support for X9279UV14Z 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 (now part of Renesas Electronics) is a semiconductor company specializing in precision analog, power management, and interface ICs for industrial, computing, and communications markets.

The X9279 series was designed as a family of digitally controlled potentiometers targeting analog trimming and calibration tasks where mechanical potentiometers fail due to wear, size, or lack of programmability.

FAQ

What is the operating voltage range for the X9279UV14Z?

The X9279UV14Z operates from 2.7V to 5.5V, as confirmed by the "X9279UV14-2.7*" ordering variant designation and Absolute Maximum Ratings table. This dual-voltage capability allows direct use with both 3.3V and 5V microcontrollers without level-shifting. The X9279UV14Z maintains full 256-tap resolution and specified wiper resistance across this entire range.

Does the X9279UV14Z support power-on recall, and how does it work?

Yes, the X9279UV14Z supports power-on recall: at power-up, it automatically loads the contents of Data Register 0 (DR0) into the volatile Wiper Counter Register (WCR). This behavior is explicitly documented in the Functional Description and Device Description sections. The X9279UV14Z thus restores a known, factory- or user-programmed wiper position without host intervention.

How many non-volatile data registers does the X9279UV14Z have, and what are their uses?

The X9279UV14Z has four non-volatile data registers (DR0–DR3), each 8-bit wide. DR0 serves as the default register loaded at power-up; all four can store independent wiper positions or system parameters like calibration offsets. Each register supports 100,000 write cycles and retains data for 100 years, making the X9279UV14Z suitable for long-life field calibration storage.

What is the function of the WP pin on the X9279UV14Z?

The WP (Write Protect) pin on the X9279UV14Z is a hardware-level enable for non-volatile writes: when pulled LOW, it prevents any writes to the four non-volatile data registers (DR0–DR3). This feature is documented in the Pin Descriptions and Principles of Operation sections. The X9279UV14Z uses WP to safeguard calibration data against accidental overwrite during normal operation or firmware updates.

Can the X9279UV14Z be used as a two-terminal variable resistor, and what are the limitations?

Yes, the X9279UV14Z can be configured as a two-terminal variable resistor by connecting either RH or RL to the wiper (RW) pin, as stated in the Functional Description. In this mode, maximum wiper current is ±3mA and power rating is 50mW at +25°C. The X9279UV14Z's 150Ω typical wiper resistance at 5V must be accounted for in low-impedance circuits to avoid significant insertion error.