Renesas X9259US24IZT1

Overview

X9259US24IZT1 from Intersil (now Renesas) is a quad digitally controlled potentiometer (XDCP™) IC implementing four independent 256-tap, 50kΩ end-to-end resistive elements with volatile wiper counter registers and nonvolatile data registers. It operates from 2.7V to 5.5V, features 2-wire serial interface, <5µA standby current, and is used for precision gain control, DC bias trimming, and programmable reference setting in analog signal chains.

For engineers reviewing the X9259US24IZT1 datasheet, X9259US24IZT1 pinout, X9259US24IZT1 application, or X9259US24IZT1 equivalent, this page delivers verified electrical parameters, industrial-grade temperature range (-40°C to +85°C), SOIC-24 package mapping, functional pin roles, and real-world circuit-level use cases - all confirmed from FN8169 Rev 6.00.

Technical Context

The X9259US24IZT1 integrates four monolithic CMOS DCPs, each with resistor ladder and CMOS switch array controlled by an 8-bit volatile Wiper Counter Register (WCR). Each DCP supports three-terminal potentiometer or two-terminal variable resistor operation, with wiper position resolution of 0.4% (1/256).

It uses a standard 2-wire (I²C-compatible) bus with device address pins A0–A3, hardware write-protect (WP), and open-drain SDA/SCL. At power-up, each WCR loads default values from nonvolatile DR#0 registers, enabling repeatable startup behavior without host initialization.

Key Specifications

Pinout & Package

Package: 24-lead SOIC (RoHS-compliant, M24.3 drawing), body width 7.5mm, lead pitch 1.27mm.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5204BRUZ10 and MCP42050-I/P, the X9259US24IZT1 uniquely delivers quad 50kΩ channels with 2-wire interface, hardware write-protect, and global register transfer - simplifying industrial calibration systems where bus efficiency and configuration safety are critical.

Availability

X9259US24IZT1 is available at Aetrix Electronics and suitable for industrial sensor conditioning, programmable power supplies, and audio equipment requiring stable component supply with guaranteed long-term availability and RoHS-compliant packaging.

Supply support for X9259US24IZT1 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 mixed-signal ICs for power management, precision analog, and interface applications.

The X9259 product line was designed for embedded analog reconfiguration tasks - delivering reliable, nonvolatile digital control of resistance in industrial, medical, and communications equipment where mechanical potentiometers fail.

FAQ

What is the maximum clock frequency supported by the X9259US24IZT1 2-wire interface?

The X9259US24IZT1 supports a maximum SCL clock frequency of 400kHz, compliant with standard-mode I²C specifications. This allows fast register access while maintaining noise immunity in electrically noisy industrial environments. The AC timing parameters - including t_CYC (2500ns), t_HIGH (600ns), and t_LOW (1300ns) - are fully characterized across the -40°C to +85°C range. All timing constraints apply directly to the X9259US24IZT1 under its specified V_CC and load conditions.

Does the X9259US24IZT1 require external pull-up resistors on SDA and SCL lines?

Yes, the X9259US24IZT1 requires external pull-up resistors on both SDA and SCL lines because its SDA pin is open-drain and SCL is a CMOS input. Typical values range from 1.8kΩ to 10kΩ depending on bus capacitance and speed requirements. The pull-ups must connect to the same V_CC rail used by the X9259US24IZT1 to ensure valid logic levels and proper ACK generation. This requirement is explicitly defined in the Functional Pin Descriptions section of the FN8169 datasheet for the X9259US24IZT1.

How does the hardware write-protect (WP) pin function on the X9259US24IZT1?

The WP pin on the X9259US24IZT1 is an active-low input that disables all nonvolatile writes to the Data Registers when pulled LOW. When WP is HIGH (or floating, if externally pulled up), normal write operations to DR#0–DR#3 are permitted. This feature prevents accidental corruption of calibrated settings during system operation or firmware updates. The WP function applies exclusively to nonvolatile register writes - volatile WCR updates and read operations remain fully functional regardless of WP state. This behavior is confirmed in the Pin Descriptions and Functional Pin Descriptions sections of the X9259US24IZT1 datasheet.

Can the X9259US24IZT1 be used as a two-terminal variable resistor, and what are the limitations?

Yes, the X9259US24IZT1 can be configured as a two-terminal variable resistor by connecting either RH or RL to the wiper RW, leaving the other terminal unconnected or tied to a fixed potential. In this mode, resistance varies from near-zero (WCR = 0x00 or 0xFF) to 50kΩ (±20%). Key limitations include maximum wiper current of ±3mA and power rating of 50mW per DCP. Exceeding these limits risks parametric shift or permanent damage. These ratings and usage guidelines are specified in the Absolute Maximum Ratings and Analog Specifications tables for the X9259US24IZT1.

What happens to wiper positions during power-up of the X9259US24IZT1?

On power-up, the X9259US24IZT1 automatically loads the contents of each DCP's DR00, DR10, DR20, and DR30 registers into their corresponding volatile Wiper Counter Registers (WCR0–WCR3). This ensures repeatable startup behavior without host intervention. The loading occurs after V_CC stabilizes and meets the t_PUW delay (max 50ms). If DR#0 registers contain factory-calibrated values, the X9259US24IZT1 resumes its last known analog configuration immediately upon power application - a key feature for mission-critical systems. This behavior is documented in the Power Up and Down Recommendations and WCR sections of the X9259US24IZT1 datasheet.