Renesas X9251UV24Z

Overview

X9251UV24Z from Renesas is a quad digitally controlled potentiometer (XDCP™) IC with 256-tap resolution, SPI interface, 50kΩ end-to-end resistance, 2.7V–5.5V supply range, and 24-lead TSSOP package. It functions as four independent programmable resistors for precision analog control in gain-setting, bias trimming, and reference adjustment circuits.

For engineers reviewing the X9251UV24Z datasheet, X9251UV24Z pinout, X9251UV24Z application, or X9251UV24Z equivalent, this device delivers nonvolatile wiper position storage, <5µA standby current, 0.4% resolution, and hardware write protection-key selection criteria for embedded analog tuning and calibration systems.

Technical Context

The X9251UV24Z implements four independent CMOS-switched resistor arrays, each with an 8-bit volatile Wiper Counter Register (WCR) controlling wiper position and four 8-bit nonvolatile Data Registers (DR00–DR33) for persistent storage. Wiper positions are updated via SPI commands including Write/Read WCR, Write/Read DR, and XFR between DR and WCR.

It supports standard SPI timing (fSCK ≤ 2 MHz), features HOLD and WP pins for bus pause and hardware write lock, and uses A0/A1 address pins to enable up to four devices on one bus. Power-up loads DR#0 values into corresponding WCRs, ensuring repeatable startup states without host intervention.

Key Specifications

Pinout & Package

Package: 24-lead TSSOP (4.4mm width), RoHS-compliant, Pb-free, M24.173 drawing.

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/SL, the X9251UV24Z offers superior resolution (256 vs 64/256 taps), integrated hardware write protection, and quad-channel density in a compact TSSOP - making it optimal for high-precision, multi-parameter calibration in space-constrained industrial and communications equipment.

Availability

X9251UV24Z is available at Aetrix Electronics and suitable for audio gain control, voltage reference trimming, LED bias regulation, RF power amplifier bias, and sensor signal conditioning requiring stable component supply and long-term calibration integrity.

Supply support for X9251UV24Z 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog power, and connectivity solutions for automotive, industrial, and IoT applications.

The X9251UV24Z belongs to Renesas' XDCP™ family of digitally controlled potentiometers, designed specifically for replacing mechanical trimmers in precision analog tuning, calibration, and parameter adjustment systems.

FAQ

What is the maximum SPI clock frequency supported by the X9251UV24Z?

The X9251UV24Z supports a maximum SPI clock frequency of 2 MHz, as specified in its AC timing characteristics. This allows reliable communication with most microcontrollers and DSPs while maintaining signal integrity and minimizing noise coupling into analog sections. The device operates correctly across its full 2.7V–5.5V supply range at this rate, and timing parameters such as tSU, tH, and tV are guaranteed within this limit. Exceeding 2 MHz may result in unreliable register access or corrupted wiper updates.

How does the X9251UV24Z handle power-up initialization?

At power-up, the X9251UV24Z automatically loads the contents of Data Register zero (DR00, DR10, DR20, DR30) into the corresponding volatile Wiper Counter Registers (WCR0–WCR3). This ensures repeatable analog behavior without host intervention. The load occurs after VCC stabilizes and meets tPUR (1 ms) and tPUW (50 ms) delays. No external reset or SPI command is required, making the X9251UV24Z ideal for systems where deterministic startup state is critical.

Can the X9251UV24Z be used as a two-terminal variable resistor?

Yes, the X9251UV24Z can be configured as a two-terminal variable resistor by connecting either RH or RL to the circuit node and leaving the other terminal unconnected or tied to a fixed potential. Each DCP supports this mode, and wiper resistance remains ≤220Ω typical at 5V. This configuration is commonly used in current-setting applications like LED biasing or op-amp gain control, where only one adjustable endpoint is needed and the full end-to-end resistance is not utilized.

What is the purpose of the HOLD pin on the X9251UV24Z?

The HOLD pin on the X9251UV24Z pauses ongoing SPI communication without resetting the serial sequence. When asserted LOW while SCK is LOW, it freezes data transfer mid-operation; bringing HOLD HIGH resumes from the exact point of interruption. This feature allows the host controller to service higher-priority interrupts without losing synchronization or requiring reinitialization - essential in real-time systems where deterministic SPI latency cannot be compromised.

Does the X9251UV24Z support daisy-chaining multiple devices on one SPI bus?

No, the X9251UV24Z does not support true daisy-chaining. It uses standard SPI with individual CS lines and A0/A1 address pins to select up to four devices on a shared bus. While SO and SI can be wired together (due to three-state outputs) to reduce pin count, each device requires its own CS signal for independent addressing. Daisy-chaining would require a shift-register architecture not present in the X9251UV24Z's SPI implementation.