WM8959 Wolfson Microelectronics Ltd., WM8959 Datasheet - Page 121

• Manufacturer Part Number: WM8959
• Description: Mobile Multimedia DAC with Dual-mode Class AB/D Speaker Driver
• Manufacturer: Wolfson Microelectronics Ltd.

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Pre-Production
Table 76 Output Discharge Control
VMID REFERENCE DISCHARGE CONTROL
The VMID reference can be discharged to AGND through internal resistors. Discharging VMID
ensures that a subsequent start-up procedure commences with a known voltage condition; this is
necessary in order to ensure maximum suppression of audible pops associated with start-up. VMID
is discharged by setting VMIDTOG, as described in Table 77.
Table 77 VMID Reference Discharge Control
R56 (38h)
Anti-Pop (1)
R57 (39h)
Anti-Pop (2)
REGISTER
REGISTER
ADDRESS
ADDRESS
5
4
3
2
1
0
0
BIT
BIT
DIS_LLINE
DIS_RLINE
DIS_OUT3
DIS_OUT4
DIS_LOUT
DIS_ROUT
VMIDTOG
LABEL
LABEL
0b
0b
0b
0b
0b
0b
0b
DEFAULT
DEFAULT
Discharges LOP and LON outputs via
approx 500Ω resistor
0 = Not active
1 = Actively discharging LOP and LON
Discharges ROP and RON outputs via
approx 500Ω resistor
0 = Not active
1 = Actively discharging ROP and RON
Discharges OUT3 output via approx 500Ω
resistor
0 = Not active
1 = Actively discharging OUT3
Discharges OUT4 output via approx 500Ω
resistor
0 = Not active
1 = Actively discharging OUT4
Discharges LOUT output via approx 500Ω
resistor
0 = Not active
1 = Actively discharging LOUT
Discharges ROUT output via approx 500Ω
resistor
0 = Not active
1 = Actively discharging ROUT
Connects VMID to ground
0 = Disabled
1 = Enabled
DESCRIPTION
DESCRIPTION
PP, May 2008, Rev 3.1
WM8959
121