Renesas X9221AWST1

Overview

X9221AWST1 from Intersil is a dual digitally controlled potentiometer (XDCP™) with 64-tap resolution per channel, 2-wire I²C-compatible serial interface, nonvolatile data register storage, and 2 kΩ end-to-end resistance. It operates from 4.5 V to 5.5 V, supports 0°C to +70°C ambient, and functions as two independent programmable resistive dividers in analog signal conditioning circuits.

For engineers reviewing the X9221AWST1 datasheet, X9221AWST1 pinout, X9221AWST1 application, or X9221AWST1 equivalent, this device delivers precise digital wiper control, EEPROM-backed multi-position storage, and direct register-oriented command execution-critical for recalibration-critical instrumentation, factory-set gain trimming, and embedded sensor biasing where mechanical potentiometer replacement is required.

Technical Context

The X9221AWST1 integrates two monolithic CMOS resistor arrays (63 segments each), each with a volatile 6-bit Wiper Counter Register (WCR) and four nonvolatile Data Registers (DR0–DR3). Wiper position is selected via decoded WCR output driving FET switches across the array; power-up loads DR0 into the WCR.

It implements a slave-only 2-wire protocol with fixed 0101xxxx binary address prefix, supports ACK polling during 10 ms nonvolatile writes, and enables real-time wiper increment/decrement via clocked SCL pulses while SDA is HIGH/LOW-enabling fine-grained host-controlled adjustment without register rewrites.

Key Specifications

Pinout & Package

Package: 20-lead SOIC (300-mil, MDP0027), RoHS-compliant Pb-free plus anneal finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AD5242BRUZ10 and MCP42010-I/P, the X9221AWST1 uniquely combines dual 64-tap channels, I²C compatibility, automatic DR0 power-up recall, and 2 kΩ low-value resistance-making it optimal for space-constrained, dual-channel analog trimming where deterministic startup behavior and bus efficiency matter most.

Availability

X9221AWST1 is available at Aetrix Electronics and suitable for industrial sensor calibration, audio signal conditioning, and programmable power supply feedback requiring stable component supply and long-term manufacturing continuity.

Supply support for X9221AWST1 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) designs high-performance analog and mixed-signal ICs for power management, precision analog, and interface applications.

The X9221A product line was engineered specifically for digital replacement of mechanical potentiometers in calibration-critical, low-power embedded systems-emphasizing nonvolatile configuration retention, I²C simplicity, and dual-channel integration.

FAQ

What is the maximum clock frequency supported by the X9221AWST1 I²C interface?

The X9221AWST1 supports a maximum SCL clock frequency of 100 kHz, as specified in its AC characteristics table. This limit ensures reliable communication timing-including tLOW (4700 ns minimum), tHIGH (4000 ns minimum), and noise suppression (100 ns glitch filter)-and aligns with standard-mode I²C operation. Exceeding 100 kHz may cause command corruption or failed ACK responses due to internal timing constraints in the X9221AWST1 interface circuitry.

Does the X9221AWST1 retain wiper position after power cycling?

Yes, the X9221AWST1 retains wiper position across power cycles via its nonvolatile Data Register 0 (DR0). On power-up, the contents of DR0 are automatically loaded into the volatile Wiper Counter Register (WCR), restoring the last-stored position. However, if the WCR was modified after power-up without writing back to DR0, that change is lost-so persistent storage requires explicit Write Data Register commands to DR0.

Can the X9221AWST1 be used as a two-terminal variable resistor?

Yes, the X9221AWST1 can operate as a two-terminal variable resistor by connecting either VH/RH or VL/RL to the same node as VW/RW, leaving the unused terminal open. This configuration uses only one end of the resistor array and the wiper, providing adjustable resistance from near-zero (at wiper = terminal) up to RTOTAL. The 2 kΩ version (X9221AWST1) supports ≤±3 mA wiper current and maintains ≤130 Ω wiper resistance in this mode.

How many unique I²C addresses can be assigned to X9221AWST1 devices on the same bus?

The X9221AWST1 supports 16 unique I²C addresses via its A0–A3 address pins, which configure the four least-significant bits of the 8-bit slave address (fixed prefix 0101xxxx). Each combination of A0–A3 logic levels (high/low) yields a distinct address, allowing up to 16 X9221AWST1 units-or mixed X9221A variants-to coexist on a single 2-wire bus without address conflict.

What is the endurance rating for nonvolatile register writes in the X9221AWST1?

The X9221AWST1 guarantees 100,000 write cycles per bit per nonvolatile data register (DR0–DR3), as confirmed in its Endurance and Data Retention specification. Each write to a register-including Write Data Register and XFR WCR to Data Register commands-consumes one cycle. With four registers per potentiometer, total endurance exceeds 800,000 register-level operations, supporting decades of field recalibration in typical industrial applications.