WM8731SEFL Wolfson Microelectronics, WM8731SEFL Datasheet - Page 32

• Manufacturer Part Number: WM8731SEFL
• Description: Audio CODECs Stereo Codec with H/P
• Manufacturer: Wolfson Microelectronics

Specifications of WM8731SEFL

• Number Of Adc Inputs: 1
• Number Of Dac Outputs: 1
• Conversion Rate: 96 KSPS
• Interface Type: Serial (2-Wire, 3-Wire, I2S)
• Operating Supply Voltage: - 0.3 V to + 3.63 V
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN EP
• Minimum Operating Temperature: - 40 C
• Number Of Channels: 2 ADC/2 DAC
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8731 / WM8731L
Figure 23 Signal Routing in Bypass Mode
w
LINEIN
12.5K
VMID
The recommended external components required to complete the application are shown in Figure 22.
Figure 22 Headphone Output Application Drawing
Recommended values are C1 = 220uF (10V electrolytic), R1 = 47k
C1 forms a DC blocking capacitor to isolate the dc of the HPOUT from the headphones. R1 form a
pull down resistor to discharge C1 to prevent the voltage at the connection to the headphones from
rising to a level that may damage the headphones.
BYPASS MODE
The WM8731/L includes a bypass mode whereby analogue line inputs are routed directly to the
analogue line outputs and headphone outputs. The scheme for this is in Figure 23.
HPOUT
INPUTS
FROM
FROM
LINE
DAC
SIDETONE (OFF)
DACSEL (OFF)
BYPASS (ON)
VMID
C1
AGND
R1
LINEOUT
VMID
PD, Rev 4.8, April 2009
Production Data
AGND
HPOUT
32