WM8734SEFL Wolfson Microelectronics, WM8734SEFL Datasheet - Page 20

• Manufacturer Part Number: WM8734SEFL
• Description: Audio CODECs Stereo CODEC
• Manufacturer: Wolfson Microelectronics

Specifications of WM8734SEFL

• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-28
• Minimum Operating Temperature: - 25 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8734
w
Figure 12 DAC Filter Schematic
The DAC digital filter can apply digital de-emphasis under software control, as shown in Table 3. The
DAC can also perform a soft mute where the audio data is digitally brought to a mute level. This
removes any abrupt step changes in the audio that might otherwise result in audible clicks in the
audio outputs.
Table 3 DAC Software Control
DAC
The WM8734 employs a multi-bit sigma delta oversampling digital to analogue converter. The
scheme for the converter is illustrated in Figure 13.
Figure 13 Multi-Bit Oversampling Sigma Delta Schematic
The DAC converts the multi-level digital audio data stream from the DAC digital filters into high
quality analogue audio.
0000101
Digital Audio
Path Control
REGISTER
FROM DIGITAL
ADDRESS
INTERFACE
AUDIO
FROM DAC
FILTERS
DIGITAL
2:1
3
BIT
DE_EMPHASIS
DEEMP
DIGITAL
DEEMP[1:0]
DACMU
LABEL
DACMU
MUTE
00
1
DEFAULT
INTERPOLATION
DIGITAL
FILTER
TO LINE OUTPUT
De-emphasis Control
(Digital)
11 = 48kHz
10 = 44.1kHz
01 = 32kHz
00 = Disable
DAC Soft Mute Control
(Digital)
1 = Enable soft mute
0 = Disable soft mute
PD, Rev 4.3, January 2009
DESCRIPTION
OUTPUTS
TO LINE
Production Data
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