AK5371VQ Asahi Kasei Microsystems, AK5371VQ Datasheet - Page 10

• Manufacturer Part Number: AK5371VQ
• Description: 2CH A/D CONVERTER WITH USB I/F
• Manufacturer: Asahi Kasei Microsystems

MS0103-E-00
The AK5371 is the advanced stereo A/D converter, which converts analog signal into USB audio class formats. As the AK5371
incorporates all functions to build USB Audio Input Device, the AK5371 doesn’t require additional micro-controller, memory, and a
transceiver. Moreover, as the AK5371 also has 20dB fixed gain pre-amplifier in addition to programmable gain amplifier (IPGA)
whose range is from +24dB to –31dB, this device is suitable for USB microphone, especially microphone array. USB microphone
can be manufactured easily by only four main components; the AK5371, one crystal, one regulator, and microphone unit(s). As the
AK5371 also has EEPROM interface, descriptors can be customized easily. The AK5371 includes the following blocks:
frequencies, the AK5371 incorporates PLL, which generates system clock and master clock for fs=8kHz, and 48kHz
master clock stop the function to observe USB specification, 500 A , until receiving the resume signal. The AK5371 notifies the
current state (normal state or suspend state) by SUS_N pin.
own ID, and string.
The AK5371 supports 5 sampling frequencies (8kHz, 11.025kHz, 22.05kHz, 44.1kHz, 48kHz). In order to support these
Mute, volume and audio format including sampling frequency are controlled by USB audio class request.
The AK5371 goes to suspend mode when the device doesn’t receive SOF for the period more than 3ms. All blocks including
As the AK5371 has Microwire
Overview of AK5371
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ASAHI KASEI
MS0103-E-00
2 channel 16bit A/D converter
Programmable Gain Amplifier (IPGA)
Fixed Gain Preamplifier
FIFO
Synchronization between A/D converter and USB bus
PLL
Audio Format
USB Serial Interface Engine
Control block of Audio Device Class
USB transceiver
EEPROM I/F
USB Suspend/Resume Support
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Microwire
20dB
Memory Size 400 bytes (16bit wide x 100 depth x 2 channel)
84dBA@fs=44.1kHz
Gain Range: from +24dB to -31dB,
Gain Step: 1dB/step
11.2896MHz crystal
Two PLLs
supports 5 frequencies : 8kHz, 11.025kHz, 22.05kHz, 44.1kHz, 48kHz
2 audio formats
Process USB Standard Requests
Translate internal A/D format to USB audio class format
Process USB Audio Class Request
- A/D_PLL: generate clock for fs=8kHz, 48kHz
- System_PLL : generate USB system clock
- Mute
- Gain/Attenuation
- Sampling Frequency Control
- 1K bit (AK93C45A)
- 2K bit (AK93C55A)
- 4Kbit (AK93C65A)
- mono 16bit LSB first
- stereo 16bit LSB first
(4-wire) type EEPROM can be used to customize Device/String Descriptor.
EEPROM I/F, the vendors can customize iManifacterer, iProduct, and the related strings to their
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[AK5371]
2001/06