News Release

- New Product Information -

AKM releases an audio CODEC for connected cars; with ability to switch the microphone path in emergencies

Product Name
Audio > Audio CODECs
48kHz 24-bit Monaural Audio CODEC (DAC+ADC)* with Analog Switch and PLL
* DAC: D/A Converter, ADC: A/D Converter
Automotive Modules, (Data Communication Module: DCM, Telematics Control Unit: TCU)
Drive Recorders, In-Vehicle Information: IVI,
e-Mirrors (electronic mirror)


More internet communication modules are now being installed in vehicles as popularity increases. Asahi Kasei Microdevices Corporation, (AKM), has released the AK4940VN, a monaural audio CODEC, (DAC + ADC), developed for communication modules.


● e-Call system and Hands-free head units can share one Microphone

The AK4940VN has an analog direct path that outputs microphone input signal directly. Therefore, it is possible to share a microphone for emergency calls and for hands-free head units.

● Support differential/single-ended/pseudo differential signals

Integrated DAC, ADC and analog direct path support differential/single-ended/pseudo differential signal formats. The ADC has a programmable gain amplifier which supports a range from -6dB to +27dB and a digital volume control supporting from Mute to +24dB. The DAC has digital volume control supporting a range from Mute to +24dB, enabling to accept a broad signal range.

● Integrated PLL

The AK4940VN generates the internal master clock from a clock for audio data transmission. This eliminates the need for wiring a master clock, contributing low EMC and saving mounting space.


Main Specifications

48kHz 24-bit Monaural Audio CODEC
Product Name AK4940VN AK4637VN
Analog Direct Path2 channels,
Signal Amplitude max. 3Vpp
Analog Input Pin2 channels Differential1 Channel Differential
Analog Output Pin2 channels differential
+ 1 channel Single-ended
1 Channel Differential
PLL with Loop FilterIntegratedIntegrated
Microcontroller InterfaceI2CI2C
Sampling Frequency8 to 48kHz8 to 48kHz
Analog Power Supply (AVDD)3.0 to 3.6V2.8 to 3.6V
Digital Core Power Supply (DVDD)Not Necessary1.6 to 1.98V
Digital I/O Power Supply (TVDD)1.7 to 3.6V1.6 to 3.6V
Operation Temperature Range-40 to 105°C-40 to 85°C
Package24-pin QFN, 4 x 4mm, 0.5mm pitch20-pin QFN, 3 x 3mm, 0.4mm pitch
AEC-Q100Support (will be in May. 2019)Supported (Dec. 2017)
Monaural 24-bit ADC
CMRR80dBNot Stated
Microphone Amplifier-6 to 27dB / 3dB step0 to 30dB / 3dB step
Digital Volume+24 to -103dB / 0.5dB step, Mute+36 to -52.5dB / 0.375dB, Mute
Monaural 24-bit DAC (Line Output)
Digital Volume+12 to -115dB / 0.5dB step, Mute+36 to -52.5dB / 0.375dB, Mute
* Information on this page is current on the date of press release.
* AKM is a 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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