WM8974GEFL/V Wolfson Microelectronics, WM8974GEFL/V Datasheet - Page 62

• Manufacturer Part Number: WM8974GEFL/V
• Description: Audio CODECs Mono Codec with Spkr
• Manufacturer: Wolfson Microelectronics

Specifications of WM8974GEFL/V

• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: QFN-24
• Minimum Operating Temperature: - 25 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

WM8974
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Table 58 Typical POR Operation (typical values, not tested)
1.
2.
3.
4.
5.
6.
Notes:
t
t
t
t
hp__midrail_off
line_midrail_on
line_midrail_off
hp_midrail_on
The lineout charge time, t
time is dependent upon the value of VMID decoupling capacitor and VMID pin input resistance
and AVDD power supply rise time. The values above were measured using a 4.7 µ F capacitor.
It is not advisable to allow DACDAT data input during initialisation of the DAC. If the DAC data
value is not zero at point of initialisation, then this is likely to cause a pop noise on the analogue
outputs. The same is also true if the DACDAT is removed at a non-zero value, and no mute
function has been applied to the signal beforehand.
The lineout discharge time, t
capacitor and the leakage resistance path to ground. The values above were measured using a
10 µ F output capacitor.
The headphone charge time, t
capacitor and VMID pin input resistance and AVDD power supply rise time. The values above
were measured using a 4.7 µ F VMID decoupling capacitor.
The headphone discharge time, t
coupling capacitor and the leakage resistance path to ground. The values above were
measured using a 100 µ F capacitor.
The VMIDSEL and BIASEN bits must be set to enable analogue output midrail voltage and for
normal DAC operation.
SYMBOL
t
dacint
MIN
TYPICAL
line_midrail_on,
500
500
2/fs
1
6
line_midrail_off,
hp_midrail_on,
hp_midrail_off,
MAX
is mainly determined by the VMID pin charge time. This
is dependent upon the value of the lineout coupling
is dependent upon the value of VMID decoupling
is dependent upon the value of the headphone
n /fs
UNIT
ms
ms
s
s
PD, Rev 4.5, September 2008
Production Data
62