Renesas X9221AYSIT1

Overview

X9221AYSIT1 from Intersil is a dual digitally controlled potentiometer (XDCP™) with 64-tap resolution per channel, 2 kΩ end-to-end resistance, and 2-wire (I²C-compatible) serial interface. It integrates two independent resistor arrays, each with volatile wiper counter registers and four nonvolatile data registers, enabling precise digital adjustment in analog signal paths. Used for gain/offset trimming, sensor calibration, and programmable biasing in industrial instrumentation and embedded control systems.

For engineers reviewing the X9221AYSIT1 datasheet, X9221AYSIT1 pinout, X9221AYSIT1 application, or X9221AYSIT1 equivalent, key selection criteria include its dual-pot architecture, 2-wire bus timing compliance (fSCL ≤ 100 kHz), nonvolatile register endurance (100,000 writes), -40°C to +85°C industrial temperature range, and SOIC-20 package compatibility with standard PCB layouts.

Technical Context

The X9221AYSIT1 implements two independent 63-segment resistor arrays with decoded 6-bit wiper counter registers (WCR), where each WCR output selects one of 64 tap points via FET switches. The device uses a slave-only 2-wire interface with fixed 4-bit device identifier (0101) and user-configurable 4-bit address (A0–A3).

Each potentiometer supports direct WCR write/read, transfer between WCR and four nonvolatile data registers (DR0–DR1 per pot), global register transfers, and real-time increment/decrement control. Power-up loads DR0 into the respective WCR, ensuring repeatable startup behavior without host intervention.

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 X9221AYSIT1 provides native dual-channel 2-wire control with guaranteed 2 kΩ resistance and industrial temperature support, simplifying design for space-constrained I²C systems requiring matched channel behavior.

Availability

X9221AYSIT1 is available at Aetrix Electronics and suitable for industrial instrumentation, embedded sensor interfaces, and programmable analog signal conditioning requiring stable component supply, long-lifecycle availability, and RoHS-compliant packaging.

Supply support for X9221AYSIT1 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, computing, and communications markets, emphasizing reliability and precision.

The X9221A product line delivers digitally controlled potentiometers optimized for replacing mechanical trimmers in automated calibration, sensor signal chains, and programmable analog subsystems with nonvolatile memory and industry-standard serial interfaces.

FAQ

What is the maximum clock frequency supported by the X9221AYSIT1 2-wire interface?

The X9221AYSIT1 supports a maximum SCL clock frequency of 100 kHz, as specified in its AC characteristics table. This limit ensures reliable ACK generation, data setup/hold timing, and noise immunity in electrically noisy industrial environments. Exceeding 100 kHz may cause communication failures or incomplete nonvolatile register writes. The X9221AYSIT1 does not support faster I²C modes like Fast-mode Plus.

Does the X9221AYSIT1 retain wiper position after power cycling?

Yes, the X9221AYSIT1 retains wiper position across power cycles by loading the contents of Data Register 0 (DR0) into the Wiper Counter Register (WCR) at power-up. This behavior is automatic and requires no host intervention. However, the WCR itself is volatile - only DR0's stored value persists, so the initial wiper position reflects DR0's last written value, not the final powered-down state of the WCR.

Can the X9221AYSIT1 be used as a two-terminal variable resistor?

Yes, the X9221AYSIT1 can operate as a two-terminal variable resistor by connecting either VH/RH or VL/RL to the wiper (VW/RW) terminal, leaving the other fixed terminal open or grounded. This configuration is explicitly supported in the datasheet and maintains the same 64-tap resolution and 2 kΩ end-to-end resistance. Wiper resistance remains ≤130 Ω, minimizing impact on low-impedance signal paths.

What is the wiper resistance specification for the X9221AYSIT1?

The X9221AYSIT1 specifies a wiper resistance of 40 Ω (typical) to 130 Ω (maximum) at ±1 mA wiper current, per the Analog Characteristics table. This low on-resistance ensures minimal insertion loss and voltage error when used in precision voltage dividers or op-amp feedback networks. The value is measured between VW/RW and the selected resistor array segment, and remains consistent across all 64 tap positions.

How many nonvolatile write cycles does the X9221AYSIT1 support per register?

The X9221AYSIT1 guarantees 100,000 nonvolatile write cycles per bit per register, as stated in the Endurance and Data Retention section. This applies to all four data registers (DR0–DR1) per potentiometer. Each write to a register consumes one cycle; repeated writes to the same register location accumulate toward this limit. The specification ensures reliable field calibration and configuration updates over the product's operational lifetime.