SPI Bus

Category: Converters, Electronics, Intersil Corporation

Overview of the X9421 Integrated Circuit

The X9421 featured in the datasheet is a Single Digitally Controlled (XDCP™) Potentiometer with several sophisticated features designed for precise electronic control. The datasheet, dated January 14, 2009, provides a comprehensive outline of the product’s capabilities and characteristics.

Key Features

Noteworthy features of the X9421 include:

64 Resistor Taps: Allows fine-grained control over resistance levels.
SPI Serial Interface: Enables read, write, and transfer operations for the potentiometer wiper.
Wiper Resistance: Provides a typical resistance of 150Ω at 5V.
Non-Volatile Data Registers: Four registers enable storing multiple wiper positions.
Power-on Recall: Automatically loads the saved wiper position upon powering up.
Low Standby Current: Maximum of 5μA to conserve power.
Voltage Range: Operates between 2.7V to 5.5V.
End-to-End Resistance Options: Available in 2.5kΩ and 10kΩ.

Description and Usage

The X9421 operates as a mechanically integrated potentiometer using 63 resistive elements in a series array. It offers varied application use, acting either as a three-terminal potentiometer or a two-terminal variable resistor for control, parameter adjustments, and signal processing tasks.

Technical Specifications

This device guarantees a data retention period of 100 years and an endurance of 100,000 data changes per bit per register, emphasizing its reliability and durability. Available in 14 Ld TSSOP and 16 Ld SOIC packaging, the low power CMOS device also adheres to RoHS compliance for environmental consideration.

Block Diagram

The block diagram in the datasheet visualizes the internal structure featuring components such as the WRITE, READ, TRANSFER, INC, DEC controls, the ADDRESS DATA STATUS pathway, the Wiper Counter Register (WCR), and the DATA REGISTERS. It also highlights the interaction between the SPI BUS INTERFACE and the potentiometer.

Precautions

The datasheet cautions that these devices are sensitive to electrostatic discharge and recommends following proper Integrated Circuit (IC) handling procedures.