4321M

Product Overview

4321M is commonly associated with Infineon / International Rectifier IR4321M, an integrated analog-input Class D audio amplifier in a compact PQFN-22 package. The device integrates a PWM controller, high-voltage gate driver and low RDS(ON) MOSFET output stage to support high-power audio amplification with a small PCB footprint. With single-channel Class D operation, analog input support, split or single power supply operation and built-in protection features, it is suitable for active speakers, powered subwoofers, home audio systems, professional audio equipment, multimedia speakers and compact high-efficiency amplifier boards.

Key Features

• Manufacturer: Infineon Technologies / International Rectifier legacy

• Marking / Short Part Number: 4321M

• Full / Related Part Number: IR4321M, IR4321MTRPBF and related Class D amplifier variants

• Device Type: Integrated analog-input Class D audio amplifier

• Product Category: Audio IC / Class D power amplifier

• Audio Input Type: Analog input

• Output Configuration: Single-channel Class D amplifier

• Output Power: 90W to 135W class depending on load, supply voltage and distortion condition

• Speaker Channel: 1 channel

• Supply Type: Split or single power supply operation depending on circuit design

• Supply Voltage: ±25V or 50V class operation depending on configuration

• Integrated Function: PWM controller, high-voltage gate driver and MOSFET output stage integrated in one package

• Output Stage: Integrated low RDS(ON) MOSFET output stage

• Protection Feature: Overcurrent protection, overtemperature protection and undervoltage protection with reset behavior depending on datasheet version

• Noise Feature: Start / stop click-noise reduction and high noise immunity depending on circuit design

• Package Type: PQFN-22L 5mm x 6mm package

• Mounting Type: Surface mount

• Key Features: Analog input, single-channel Class D amplification, integrated controller / driver / MOSFET stage, compact PQFN package, high power density and protection functions

• Typical Use: Active speakers, powered subwoofers, home audio systems, multimedia speakers, professional audio equipment and compact amplifier boards

• Ordering / Packaging Note: 4321M is usually a shortened marking-style reference for IR4321M variants; buyers should verify the full Infineon ordering code, package suffix, output power condition, supply configuration, top marking, packing format and datasheet revision before production or repair use.

Applications

4321M can be used in electronic systems that require a compact high-efficiency Class D audio amplifier with analog input and integrated power stage. Typical applications include active loudspeakers, powered subwoofers, home theater systems, multimedia speakers, portable audio equipment, professional audio modules, amplifier boards, consumer electronics, maintenance projects and legacy audio amplifier repair. It is also suitable for BOM review where an Infineon / International Rectifier IR4321M family Class D amplifier IC is required.

Quality & Sourcing

Antrex Electronics can support 4321M sourcing with stock availability checks, RFQ quotation, package confirmation, date code review and shipment arrangement. For project-based purchasing, buyers can provide quantity, target price, required date code, packaging requirements and application information for faster quotation support.

For quality control, Antrex Electronics can help arrange product photos, label review, visual inspection and third-party testing support when required. OEMs, EMS providers, repair centers and electronic component buyers are welcome to send BOM lists or hard-to-find part requests for sourcing assistance.