WM8781

The WM8781 is a high performance, low cost stereo audio ADC designed for recordable media applications.

The device offers stereo line level inputs along with two control input pins (FORMAT, IWL) to allow operation of the audio interface in three industry standard modes. An internal op-amp is integrated on the front end of the chip to accommodate analogue input signals greater than 1Vrms. The device also has a high pass filter to remove residual DC offsets.

The WM8781 offers Master or Slave mode clocking schemes. A control input pin M/S is used to allow Slave mode operation or Master mode operation. A stereo 24-bit multibit sigma-delta ADC is used with 128x, 64x or 32x over-sampling, according to sample rate. Digital audio output word lengths from 16-24 bits and sampling rates from 8kHz to 192kHz are supported.

The device is a hardware controlled device and is supplied in a 20-lead SSOP package. The features of WM8781 are SNR 102dB ('A' weighted @ 48kHz), THD -90dB (at 1dB), Sampling Frequency: 8 192kHz, Master or Slave Clocking Mode, System Clock (MCLK): 128fs, 192fs, 256fs, 384fs, 512fs, 768fs, Audio Data Interface Modes(16-24 bit), 2S, 16-24 bit Left, 16-24 bit Right Justified, Supply Voltages(Analogue 2.7 to 5.5V; Digital core: 2.7V to 3.6V), 20-lead SSOP package.The applications of WM8781 are  Recordable DVD Players, Personal Video Recorders, STB, Studio Audio Processing Equipment.

Absolute Maximum Ratings of WM8781are 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. Wolfson tests its package types according to IPC/JEDEC J-STD-020B for Moisture Sensitivity to determine acceptable storage conditions prior to surface mount assembly. These levels are: MSL1 = unlimited floor life at <30°C / 85% Relative Humidity. Not normally stored in moisture barrier bag. MSL2 = out of bag storage for 1 year at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag. MSL3 = out of bag storage for 168 hours at <30°C / 60% Relative Humidity. Supplied in moisture barrier bag.

The Moisture Sensitivity Level for each package type of the WM8781 is specified in Ordering Information. Digital supply voltage=-0.3V to +3.63V, Analogue supply voltage=-0.3V to +7V, Voltage range digital inputs=DGND -0.3V to DVDD + 0.3V, Voltage range analogue inputs=AGND -0.3V to AVDD +0.3V, +Operating temperature range, TA=-25°C to +85°C, Storage temperature after soldering=-65°C to +150°C.