Features: • Audio Performance
− 97dB SNR ('A' weighted @ 48kHz) ADC
− 100dB SNR ('A' weighted @ 48kHz) DAC
− 1.42 3.6V Digital Supply Operation
− 2.7 3.6V Analogue Supply Operation
• ADC and DAC Sampling Frequency: 8kHz 96kHz
• Selectable ADC High Pass Filter
• 2 or 3-Wire MPU Serial Control Interface
• Programmable Audio Data Interface Modes
− I2S, Left, Right Justified or DSP
− 16/20/24/32 bit Word Lengths
− Master or Slave Clocking Mode
• Stereo Audio Inputs and Outputs
• Microphone Input and Electret Bias with Side Tone Mixer
• Input and Output Volume and Mute Controls
• Highly Efficient Headphone Driver
• Playback Mode Power Consumption < 18mW
• Analogue Pass Through Power Consumption < 9mW
• 28-Pin SSOP PackageApplication• Portable MP3 Players and Recorders
• CD and Minidisc RecordersPinout
SpecificationsAbsolute Maximum Ratings are stress ratings only. Permanent damage to the device may be caused by continuously operating at or beyond these limits. Device functional operating limits and guaranteed performance specifications are given under Electrical Characteristics at the test conditions specified.
ESD Sensitive Device. This device is manufactured on a CMOS process. It is therefore generically susceptible to damage from excessive static voltages. Proper ESD precautions must be taken during handling and storage of this device.
| CONDITION |
MIN |
MAX |
| Digital supply voltage |
-0.3V |
+3.63V |
| Analogue supply voltage |
-0.3V |
+3.63V |
| Voltage range digital inputs |
DGND -0.3V |
DVDD +0.3V |
| Voltage range analogue inputs |
AGND -0.3V |
DVDD +0.3V |
| Master Clock Frequency (see Note 4) |
|
40MHz |
| Operating temperature range, TA |
-10°C |
+70°C |
| Storage temperature |
-65°C |
+150°C |
| Package body temperature (soldering 10 seconds) |
|
+240°C |
| Package body temperature (soldering 2 minutes) |
|
+183°C |
Notes:
1. Analogue and digital grounds must always be within 0.3V of each other.
2. The digital supply core voltage (DCVDD) must always be less than or equal to the analogue supply voltage (AVDD) ordigital supply buffer voltage (DBVDD).
3. The digital supply buffer voltage (DBVDD) must always be less than or equal to the analogue supply voltage (AVDD).
4. When CLKIDIV2 = 1.
Descriptionintegrated headphone driver. It offers the user the unique ability to independently program the ADC and DAC sample rates from a single clock source. The WM8731 is designed specifically for portable MP3 audio and speech players and recorders. The WM8731 is also ideal for MD, CD-RW machines and DAT recorders.
Stereo line and mono microphone level audio inputs of the WM8731 are provided, along with a mute function, programmable line level volume control and a bias voltage output suitable for an electret type microphone.
Stereo 24-bit multi-bit sigma delta ADCs and DACs of the WM8731 are used with oversampling digital interpolation and decimation filters. Digital audio input word lengths from 16-32 bits and sampling rates from 8kHz to 96kHz are supported.
Stereo audio outputs of the WM8731 are buffered for driving headphones from a programmable volume control, line level outputs are also provided along with anti-thump mute and power up/down circuitry.
The WM8731 is controlled via a 2 or 3 wire serial interface. The interface provides access to all features including volume controls, mutes, de-emphasis and extensive power management facilities. The device is available in a small 28- pin SSOP package.
WM8731 Data Sheet
