Features: • Audio Performance
− 100dB SNR ('A' weighted @ 48kHz) DAC
− 1.42 3.6V Digital Supply Operation
− 2.7 3.6V Analogue Supply Operation
• DAC Sampling Frequency: 8KHz 96KHz
• 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
• Stereo Audio Outputs
• Output Volume and Mute Controls
• Highly Efficient Headphone Driver
• Playback Mode Power Consumption < 18mW
• 20-Pin SSOP PackageApplication• Portable MP3 Players
• CD and Minidisc PlayersPinout
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).
DescriptionThe WM8721 is a low power stereo DAC with an integrated headphone driver. The WM8721 is designed specifically for portable MP3 audio and speech players. The WM8721 is also ideal for MD, CD machines and DAT players.
Stereo 24-bit multi-bit sigma delta DACs are used with oversampling digital interpolation filters. Digital audio input word lengths from 16-32 bits and sampling rates from 8KHz to 96KHz are supported.
Stereo audio outputs 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 device is controlled via a 2 or 3 wire serial interface.
The interface of the WM8721 provides access to all features including volume controls, mutes, de-emphasis and extensive power management facilities. The device is available in a small 20- pin SSOP package.
A USB mode of the WM8721 is provided where all audio rates can be derived from a simple 12MHz MCLK, saving on need for PLL or multiple crystals.
WM8721 Data Sheet
