WM8734SEFL Wolfson Microelectronics, WM8734SEFL Datasheet - Page 43

• 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
MINIMISING POP NOISE AT THE ANALOGUE OUTPUTS
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To minimise any pop or click noise when the system is powered up or down, the following procedures
are recommended.
POWER UP SEQUENCE
POWER DOWN SEQUENCE
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Switch on power supplies. By default the WM8734 is in Standby Mode, the DAC is
digitally muted and the Audio Interface and Outputs are all OFF.
Set all required bits in the Power Down register (0Ch) to ‘0’; EXCEPT the OUTPD
bit, this should be set to ‘1’ (Default).
Set required values in all other registers except 12h (Active).
Set the ‘Active’ bit in register 12h.
The last write of the sequence should be setting OUTPD to ‘0’ (active) in register
0Ch, enabling the DAC signal path, free of any significant power-up noise.
Set the OUTPD bit to ‘1’ (power down).
Remove the WM8734 supplies.
PD, Rev 4.3, January 2009
Production Data
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