WM8961 Datasheet, PDF (45/116 Pages) Wolfson Microelectronics plc – Ultra-Low Power Stereo CODEC with 1W Stereo Class D Speaker Drivers and Ground Referenced Headphone Drivers

WM8961
Pre-Production
Figure 19 Recommended Headphone Output Configuration
HEADPHONE OUTPUT BIAS BOOST
In order to increase the signal to noise ratio (SNR) of the headphone output, the HP_PGAS_BIAS[2:0]
and HP_BIAS_BOOST[2:0] register bits can be used to increase the bias current to the headphone
output drive as shown in Table 31. There will be a slight increase in power consumption when a bias
boost greater than x1 is selected.
REGISTER
ADDRESS
R68 (44h)
Analogue PGA
Bias
BIT
LABEL
2:0 HP_PGAS_BIA
S[2:0]
R71 (47h)
2:0
Analogue HP 2
HP_BIAS_BOO
ST[2:0]
Table 31 Headphone Output Bias Boost
DEFAULT
DESCRIPTION
011
Headphone PGA bias options
000
x2
001
Reserved
010
Reserved
011
x1
100-111 Reserved
011
Boost bias into headphone driver
000:
x2
001:
Reserved
010:
Reserved
011:
x1
100-111 Reserved
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PP, August 2009, Rev 3.1
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