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
BIT
LABEL
DEFAULT
DESCRIPTION
R68 (44h)
Analogue PGA
Bias
2:0
HP_PGAS_BIA
S[2:0]
011
Headphone PGA bias options
000
001
010
011
x 2
Reserved
Reserved
x 1
100-111 Reserved
R71 (47h)
Analogue HP 2
2:0
HP_BIAS_BOO
ST[2:0]
011
Boost bias into headphone driver
000:
001:
010:
011:
x2
Reserved
Reserved
x1
100-111 Reserved
Table 31 Headphone Output Bias Boost
PP, August 2009, Rev 3.1
w
45
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
