Renesas X9221AUSIZT1

Overview

X9221AUSIZT1 from Intersil is a dual digitally controlled potentiometer (XDCP™) with 64-tap resolution per channel, 2-wire I²C-compatible serial interface, and nonvolatile storage of four wiper positions per pot. It operates from 5V ±10%, supports industrial temperature range (–40°C to +85°C), and is housed in a 20-lead SOIC package. Used for precision analog trimming in sensor calibration and power supply feedback loops.

For engineers reviewing the X9221AUSIZT1 datasheet, X9221AUSIZT1 pinout, X9221AUSIZT1 application, or X9221AUSIZT1 equivalent, key selection criteria include dual-pot integration, 100k write endurance per register, 10ms nonvolatile write time, 64-step resolution, and compatibility with standard 2-wire bus timing (fSCL ≤ 100 kHz).

Technical Context

The X9221AUSIZT1 integrates two independent 63-element resistor arrays with decoded 6-bit wiper counter registers (WCR) and four nonvolatile data registers (DR0–DR3) per pot. Each WCR controls FET-switched tap selection across its array, enabling precise voltage division or variable resistance configuration.

Communication uses a slave-mode 2-wire protocol with fixed device type identifier 0101b and user-configurable A0–A3 address bits. Instructions include direct WCR write/read, data register transfer, and real-time increment/decrement-supporting both volatile adjustment and persistent setting recall at power-up from DR0.

Key Specifications

Pinout & Package

Package: 20-lead SOIC (300-mil body, MDP0027 footprint), RoHS-compliant Pb-free termination.

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 X9221AUSIZT1 uniquely delivers dual 64-tap pots with four nonvolatile registers per channel in a single SOIC-20 package-enabling compact, self-contained analog trimming without external memory or multiple ICs.

Availability

X9221AUSIZT1 is available at Aetrix Electronics and suitable for industrial sensor calibration, programmable power supplies, LED driver feedback networks, and analog filter tuning requiring stable component supply across extended temperature ranges.

Supply support for X9221AUSIZT1 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 industrial, communications, and computing markets.

The X9221A product line delivers digitally programmable analog front-end components optimized for precision trimming, calibration, and dynamic gain/offset control in resource-constrained embedded systems.

FAQ

What is the maximum clock frequency supported by the X9221AUSIZT1 2-wire interface?

The X9221AUSIZT1 supports a maximum SCL clock frequency of 100 kHz, as specified in its AC characteristics table. This limit ensures reliable setup/hold timing for data transfer and acknowledges under worst-case bus capacitance conditions. Exceeding 100 kHz may cause communication failures or incomplete nonvolatile writes. The X9221AUSIZT1 does not support fast-mode (400 kHz) or high-speed I²C protocols.

Does the X9221AUSIZT1 retain wiper position after power cycling?

Yes, the X9221AUSIZT1 retains wiper position after power cycling via automatic recall of Data Register 0 (DR0) into the Wiper Counter Register (WCR) at power-up. This behavior is guaranteed across the full industrial temperature range (–40°C to +85°C). However, DR0 must be explicitly written prior to power-down to preserve the desired setting; default DR0 contents are not guaranteed at first power-on.

Can the X9221AUSIZT1 be used as a two-terminal variable resistor?

Yes, the X9221AUSIZT1 can be configured as a two-terminal variable resistor by connecting either VH or VL to VW (wiper), leaving the unused terminal open. This mode is explicitly supported in the datasheet and maintains the same 64-tap resolution and 10 kΩ total resistance. The wiper resistance (RW) is 40–130 Ω, which must be accounted for in low-resistance applications.

How many unique wiper positions can be stored nonvolatily in the X9221AUSIZT1?

The X9221AUSIZT1 stores four unique wiper positions nonvolatily per potentiometer - one in each of Data Registers DR0 through DR3. These registers are independent for Pot 0 and Pot 1, allowing eight total stored positions (four per channel). Each register supports 100,000 write cycles and 100-year data retention at +25°C.

What is the function of the RES pins on the X9221AUSIZT1?

The RES pins (pins 12, 13, and 18) on the X9221AUSIZT1 are reserved and have no internal connection. The datasheet explicitly states they must be left unconnected or tied to VSS (ground) - floating these pins is not recommended. Connecting them to VSS provides noise immunity and avoids potential coupling paths, especially in high-density PCB layouts.