Renesas X9258US24IT1

Overview

X9258US24IT1 from Intersil (now Renesas) is a quad digital potentiometer IC integrating four independent 256-tap resistor arrays with volatile wiper counter registers and four non-volatile data registers per channel, operating from dual analog supplies (±2.7V to ±5.5V) and a 2.7V–5.5V system supply, used for precision analog gain/offset trimming in mixed-signal instrumentation.

For engineers reviewing the X9258US24IT1 datasheet, X9258US24IT1 pinout, X9258US24IT1 application, or X9258US24IT1 equivalent, key selection criteria include its 2-wire I²C-compatible interface, 50kΩ end-to-end resistance, 40Ω typical wiper resistance at ±5V, <5µA standby current, and SOIC-24 package with hardware write-protect (WP) support.

Technical Context

The X9258US24IT1 implements four independent digitally controlled potentiometers using 255-series resistive elements per array, each with CMOS-switched wiper taps controlled by an 8-bit volatile Wiper Counter Register (WCR). Each channel supports direct WCR writes, register-to-WCR transfers, and real-time increment/decrement via SCL edge-triggering.

It uses a 2-wire serial interface compliant with standard I²C timing (400kHz max), with slave address formed by fixed 0101b type identifier and user-configurable A0–A3 pins. Nonvolatile storage (100-year retention, 100k-cycle endurance) preserves wiper positions across power cycles, with automatic DR0→WCR load at power-up.

Key Specifications

Pinout & Package

Package: 24-lead SOIC (300 mil), RoHS-compliant, Pb-free (e3 termination).

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5204BRUZ10 and MCP42050-I/P, the X9258US24IT1 uniquely delivers quad-channel 50kΩ bipolar operation with hardware write protection and 100-year nonvolatile storage-making it the only choice for field-deployed instruments requiring tamper-resistant, maintenance-free analog calibration.

Availability

X9258US24IT1 is available at Aetrix Electronics and suitable for industrial sensor calibration, medical instrumentation biasing, audio signal level control, and test & measurement equipment requiring stable component supply and long-term calibration integrity.

Supply support for X9258US24IT1 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 (acquired by Renesas Electronics in 2017) is a semiconductor company specializing in high-performance analog and power management ICs for industrial, aerospace, and medical applications.

The X9258 product line was designed for precision analog trimming in harsh environments-emphasizing nonvolatile calibration retention, bipolar rail support, and robust ESD tolerance for field-replaceable modules and certified instrumentation.

FAQ

What is the maximum clock frequency supported by the X9258US24IT1 2-wire interface?

The X9258US24IT1 supports a maximum I²C-compatible clock frequency of 400kHz, with guaranteed timing margins including tHIGH ≥600ns and tLOW ≥1300ns. This allows reliable communication with standard microcontrollers and avoids timing violations in noise-prone industrial environments. The X9258US24IT1 also supports standard start/stop conditions and acknowledge polling during nonvolatile writes.

Does the X9258US24IT1 retain wiper settings after power cycling?

Yes-the X9258US24IT1 automatically loads the contents of Data Register 0 (DR0) into the volatile Wiper Counter Register (WCR) at power-up. Since DR0 is nonvolatile with 100-year data retention and 100,000-cycle endurance, the last stored wiper position is restored reliably across power cycles without host intervention.

Can the X9258US24IT1 operate with unipolar analog supplies?

No-the X9258US24IT1 requires both V+ and V− analog supply rails to function correctly. Its resistor arrays are designed for true bipolar operation (e.g., ±2.7V to ±5.5V), and applying only a positive rail or grounding V− violates absolute maximum ratings and may cause malfunction or damage. Unipolar alternatives like the MCP42050 should be considered instead.

How does the hardware write-protect (WP) pin affect nonvolatile register writes on the X9258US24IT1?

When the WP pin is driven LOW, the X9258US24IT1 blocks all nonvolatile writes to its sixteen data registers (four per channel), preventing accidental overwrites of factory or field-calibrated values. This hardware lock operates independently of software commands-ensuring protection even if firmware fails or is compromised. WP has no effect on volatile WCR updates or reads.

What is the wiper response time after issuing a Write Wiper Counter Register command to the X9258US24IT1?

After issuing a Write Wiper Counter Register command, the X9258US24IT1 updates its internal wiper position within 10µs (tWRL), as specified in the datasheet. This fast settling enables real-time analog loop adjustments in closed-control systems such as adaptive filter tuning or dynamic gain compensation without perceptible latency.