AS3422-EQFP-500

Overview

The AS3422-EQFP-500 is a low-power ambient noise-canceling speaker driver designed for headsets and headphones. It features a fully analog implementation to minimize power consumption and system BOM cost while enhancing voice quality. The device supports feed-forward and feedback topologies, offering 12–30dB noise reduction across a 10–3000Hz frequency range. It includes a high-efficiency headphone amplifier delivering up to 2x23mW at 32Ω with 100dB SNR. Integrated OTP ROM allows for microphone gain calibration and application-specific settings. The unit operates on a fixed 1.0–1.8V supply with an internal charge pump.

Feature Summary

• Fully analog ambient noise cancellation supporting both feed-forward and feedback topologies for effective background noise reduction.
• High-efficiency stereo headphone amplifier with bridged mode capability for higher impedance loads and pop-free startup.
• Integrated OTP ROM for storing microphone gain calibration and application-specific configuration settings.
• Low power consumption architecture with automatic block shutdown in music playback mode to extend battery life.

Applications

• Stereo Bluetooth headsets
• Stereo wireless headsets
• Headphones with active noise cancellation
• Ear pieces requiring ambient noise reduction

Procurement Notes

Verify the package type matches the datasheet specification of QFN32 with 0.5mm pitch, as the model suffix may indicate variations. Confirm that the ordering code corresponds to the specific revision required for your design. Ensure compatibility with the 1.0V to 1.8V supply voltage range during integration. Check for any specific production trimming requirements stored in the OTP memory.

Selection Notes

Select this component when a fully analog solution is preferred over DSP implementations to reduce system cost and power usage. It is suitable for designs requiring simple SW calibration via line-in or serial interface. Consider the QFN32 package if space constraints allow for the 0.5mm pitch footprint. Evaluate the need for feedback topology support, which distinguishes it from the feed-forward only AS3421 variant.

Part Context

The AS3422 is part of the AS3421/22 family of low-power ambient noise-canceling speaker drivers manufactured by ams-OSRAM USA INC. While the AS3421 offers a single operational amplifier for feed-forward applications, the AS3422 includes an additional op-amp stage to support feedback ANC topologies. Both devices share similar power management and audio processing features but differ in their filtering capabilities and package options.

Replacement Considerations

The AS3421 is a related variant within the same family but lacks the second operational amplifier required for feedback ANC configurations. Verify that the target application utilizes a feed-forward topology before considering the AS3421 as a substitute. Package differences between QFN24 and QFN32 must be accounted for in PCB layout changes.