WM8985
Pre-Production
VMID
The analogue circuitry will not operate unless VMID is enabled. The impedance of the VMID resistor
string, together with the decoupling capacitor on the VMID pin will determine the start-up time of the
VMID circuit.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R1 (01h)
1:0
VMIDSEL
00
Reference string impedance to VMID pin
(Determines startup time):
Power
management 1
00 = off (250kΩ VMID to AGND1)
01 = 100kΩ
10 = 500kΩ
11 = 10kΩ (for fast startup)
Table 51 VMID Impedance Control
BIASEN
The analogue amplifiers will not operate unless BIASEN is enabled.
REGISTER
ADDRESS
BIT
LABEL
DEFAULT
DESCRIPTION
R1 (01h)
3
BIASEN
0
Analogue amplifier bias control
0 = disabled
Power
management 1
1 = enabled
Table 52 Analogue Bias Control
PP, Rev 3.4, October 2006
w
88
WOLFSON [ WOLFSON MICROELECTRONICS PLC ]
