SSM4321ACBZ-R7

Overview

The SSM4321 is a mono Class-D audio amplifier utilizing filterless spread-spectrum Σ-Δ modulation. It operates from a PVDD supply of 2.5 V to 5.5 V and an IOVDD supply of 1.42 V to 3.6 V. Output power reaches 2.9 W into a 3 Ω load at 5.0 V with 10% THD+N, or 2.2 W into 4 Ω and 1.4 W into 8 Ω at 5.0 V with 100 dB SNR. The device features integrated ADCs for output current (16-bit), output voltage (16-bit), and PVDD supply sensing (8-bit). Digital data is available via TDM, I2S, Left Justified, or PDM interfaces.

Feature Summary

• Integrates analog-to-digital converters for real-time monitoring of output current, output voltage, and the PVDD supply rail.
• Employs spread-spectrum pulse density modulation to minimize electromagnetic interference emissions.
• Includes pop-and-click suppression circuitry to reduce audible transients during power-up and shutdown sequences.
• Supports flexible gain adjustment from 0 dB to 12 dB in 3 dB increments using a single external resistor.

Applications

• Portable multimedia devices requiring low EMI audio amplification
• Automotive infotainment systems with digital bus integration
• Smart home speakers and voice-controlled assistants
• Industrial control panels with audio feedback capabilities

Procurement Notes

Verify that the specific ordering suffix matches the required package configuration and reel specifications. Confirm that the input signal interface aligns with the selected serial mode, as the device requires a BCLK input to operate. Ensure sense resistor values are appropriate for the target load impedance to maintain accurate ADC readings.

Selection Notes

Select this component when system design requires simultaneous audio amplification and digital feedback of amplifier status parameters. The fixed 80 kΩ input impedance must be considered during front-end matching. Verify that the PCB layout accommodates the 16-ball WLCSP package dimensions and thermal requirements for the intended power output levels.

Part Context

This device belongs to the Analog Devices SSM series of audio amplifiers. It is designed for applications where board space is limited due to its filterless architecture. The inclusion of digital sensing outputs distinguishes it from standard Class-D amplifiers by enabling closed-loop monitoring without additional discrete components.

Replacement Considerations

Direct substitutes require matching the WLCSP package and digital interface capabilities. Verify that any replacement supports the same spread-spectrum modulation technique to ensure comparable EMI performance. Check that the replacement offers similar gain adjustability and shutdown current characteristics.