AKM launches a single chip audio CODEC with integrated capless headphone amplifier

Asahi Kasei Microsystems (AKM), a leading supplier of audio ICs for professional and consumer markets, has introduced the AK4665, a 20-bit stereo A/D and D/A converter with a built-in microphone and a capless headphone amplifier.
The is device is ideal for mobile phones, smart phones, music players and personal media players.
The AK4665 follows on from the headphones-on-chip approach of the AK4569. A charge pump circuit has been added, which creates a negative power supply for the headphone amplifier. This allows the audio signal to be zero volt biased, thus eliminating the need for external DC blocking capacitors and therefore saving significant board space.
The AK4665 also features a newly-developed mute circuit for fast 20 ms pop-free on/off switching. The analogue power supply, 2.6V to 3.6V, achieves a wide dynamic range for good audio performance, while the digital power supply for external control interfacing operates from 1.6V, giving the whole system a low power advantage.
The AK4665’s digital recording automatic level control (ALC) provides a high-quality recording platform and also saves on power consumption. The AK4665 has upgraded to stereo output and built-in volume functions are independent of headphone output, to allow separate volume control of an external device such as a stereo speaker amplifier. Differences in multi-source recording levels are adjusted by a sophisticated ALC circuit ensuring a constant playback volume.
Completing the AK4665’s function-rich offerings are delta-sigma architecture, an integrated PGA microphone amplifier, integrated microphone power supply, playback digital volume and bass boost circuits, stereo and mono external analogue inputs, independent power on/off switching for each circuit block, and a three-wire uP interface.
The AK4665 is available in a 32-pin QFN package. Evaluation boards and samples are available now.
(GB)