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DESCRIPTION
The WM8737L is a low power stereo audio ADC designed
specifically for portable applications such as minidisc and
memory audio / voice recorders.
The device offers three sets of stereo inputs, which can be
configured for line-level signals, for internal or table-top
microphones, or for DC measurement (battery monitor). A
programmable gain amplifier can be used for automatic level
control (ALC) with user programmable hold, attack and
decay times. The device also has a selectable high pass
filter to remove residual DC offsets.
If the signal source is mono, the WM8737L can run in mono
mode, saving power. It can also mix two channels to mono,
either in the analogue or the digital domain.
Master or slave mode clocking schemes are offered. Stereo
24-bit multi-bit sigma-delta ADCs are used with digital audio
output word lengths from 16-32 bits, and sampling rates
from 16kHz to 96kHz supported.
The device is controlled via a 2 or 3 wire serial interface.
The interface provides access to all features including gain
controls, analogue or digital mono mixing, and power
management facilities. The device is supplied in a leadless
5x5mm QFN package.
WM8737L
Stereo ADC with Microphone Preamplifier
FEATURES
SNR 97dB (‘A’ weighted @ 3.3V, 48kHz, normal power
mode)
THD –84dB (at –1dB, 3.3V, normal power mode)
Complete Stereo / Mono Microphone Interface
- Programmable microphone preamp
- Automatic Level Control
- Low-noise microphone bias voltage
Configurable Power / Performance
Low Power Mode
- 8.5mW at AVDD = 1.8V (stereo, mic preamps off)
- 20mW at AVDD = 3.3V (stereo, mic preamps off)
Low Supply Voltages
- Analogue 1.8V to 3.6V
- Digital core: 1.42V to 3.6V
- Digital I/O: 1.8V to 3.6V
256fs / 384fs or USB master clock rates: 12MHz, 24MHz
Audio sample rates: 16, 22.05, 24, 32, 44.1, 48, 88.2, 96kHz
generated internally from master clock
32-pin QFN package, 5 x 5 x 0.9mm
APPLICATIONS
Memory Audio / Voice Recorders
Minidisc Recorders
Portable Digital Music Systems
BLOCK DIAGRAM
LINSEL
RINSEL
VREFP
VREFN
AVDD
VREF
50K
SDI N
CSB
VMID
MODE
VREFP
VREFN
WOLFSON MICROELECTRONICS plc
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Production Data, January 2012, Rev 4.4
Copyright
2012
Wolfson Microelectronics plc
AGND
SCLK
AUDIO
INTERFACE
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
