News Release

- New Product Information -

AKM develops a high-quality low-power 4-ch A/D converter for multi-microphone recording

Product Name
Audio > Audio A/D converter
4-channel 32-bit A/D converter
DR: 105dB, THD+N: -90dB
Sampling Frequency: 8 to 192kHz
Built-in MIC amplifier and MIC power supply
Conference system, microphone array system, smart speaker, baby or pet monitor, IC recorder


Asahi Kasei Microdevices Corporation (AKM) has developed a low-power 4-channel 32-bit A/D converter (ADC) with integrated low-noise microphone amplifiers. It includes digital signal processing blocks, such as filtering and level control, that are required for a digital microphone input.
Mass production of the AK5704 is scheduled for September 2019.


- Superior low-noise recording with low power consumption

The 32-bit AK5704 achieves a dynamic range of 105dB and -90dB THD+N, enabling products to take advantage of the full performance of high-SNR microphones. It is ideal for high-resolution recordings, as well as applications requiring excellent far-field response over 5m. The AK5704 is also extremely power-efficient, consuming only 17mW in active mode.

- VAD feature further reduces system power consumption

The AK5704 incorporates a new Voice Activity Detector (VAD). Using the VAD as a boot trigger can significantly reduce system power consumption, as the rest of the device may be powered off while the VAD consumes only 2.7mW while waiting for a wake-word.

- Supports Multiple Parallel Connections

Multiple AK5704s may be connected in parallel to create a system supporting up to 16 microphones.

- Supports Ultrasonic Recording

The AK5704 supports up to a 192kHz sampling frequency and can be combined with a wideband microphone to achieve ultrasonic band recording.

Main Specifications

Low-power 4-ch 32-bit A/D converter with MIC amplifier
ADC4-channel 32-bit A/D converter
Digital Filter: 2 types (Short Delay Sharp Roll-off, Voice)
DR: 105dB, THD+N: -90dB
Sampling Frequency8 to 192kHz
MIC AmplifierSingle-ended or full-differential inputs
0 to +30dB, 3dB step
MIC Power Supply2 outputs
2.8V / 2.5V / 1.8V / AVDD Direct
Programmable Phase AdjustmentAvailable
Microphone Sensitivity AdjustmentAvailable
Digital Voice Activity DetectorAvailable
Programmable Digital FilterMixer, 2nd order HPF and LPF, Automatic Level Control
Digital Audio interfaceI2S, MSB-justified, PCM Short/Long, Cascade TDM
Control I/FI2C (400kHz)
Power SupplyAVDD = 1.7 to 1.9V or 3.0 to 3.6V
TVDD = 1.65 to 3.6V
Power Consumption9.7mW (2-ch ADC, AVDD=3.3V, fs-48kHz, Slave mode)
17.0mW (4-ch ADC, AVDD=3.3V, fs-48kHz, Slave mode)
2.7mW (VAD, AVDD=1.8V, fs-16kHz, Slave mode)
Operation Temperature-40 to 85℃
Package28-pin QFN (4mm x 4mm, 0.4mm pitch)

* Information on this page is current on the date of press release.
* AKM is trademark of Asahi Kasei Microdevices Corporation in Japan, Europe and the United States.
* Appellations, company names and product names on this page are trademarks or registered trademarks of respective companies.

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