wm9081 Wolfson Microelectronics plc, wm9081 Datasheet - Page 50

• Manufacturer Part Number: wm9081
• Description: Mono Dac With 2.6w Class Ab/d Speaker Driver, Dynamic Range Controller And Retune Mobile Parametric Equalizer
• Manufacturer: Wolfson Microelectronics plc

WM9081
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Table 28 DC gain and AC gain
The speaker mode select and the speaker gain controls are described in Table 29. Note that the BTL
output configuration provides an additional 6dB gain.
Table 29 Speaker Output Control
LINE OUTPUT CONFIGURATION
The line output, LINEOUT, provides a single-ended analogue output for connection to other circuits.
Note that the line output is referenced to VMID, and external DC-blocking capacitors are required
when connecting this output to other devices.
The line output is enabled and controlled using the registers described in the “Output Signal Path”
section.
DC GAIN = AC GAIN
R9 (09h)
Analogue
Speaker 1
R10 (0Ah)
Analogue
Speaker 2
REGISTER
ADDRESS
DC GAIN [5:3] AND AC GAIN [2:0] FROM OUTPUT MIXER
110 – 111
000
001
010
011
100
101
OUTPUT TO SPEAKER AMP INPUT
BIT
5:3
2:0
6
SPK_DCGAIN
[2:0]
SPK_ACGAIN [2:0]
SPK_MODE
Gain [dB]
Reserved
LABEL
2.1
2.9
3.6
4.5
5.1
0
DEFAULT
(+3.6dB)
(+3.6dB)
011
011
0
Reserved
1.00x
1.27x
1.40x
1.52x
1.67x
Gain
1.8x
Speaker Output DC Gain
000 = x1 boost (0dB)
001 = x1.27 boost(2.1dB)
010 = x1.4 boost (2.9dB)
011 = x1.52 boost (3.6dB)
100 = x1.67 boost (4.5dB)
101 = x1.8 boost (5.1dB)
110-111 = Reserved
Speaker Output AC Gain
000 = x1 boost (0dB)
001 = x1.27 boost(2.1dB)
010 = x1.4 boost (2.9dB)
011 = x1.52 boost (3.6dB)
100 = x1.67 boost (4.5dB)
101 = x1.8 boost (5.1dB)
110-111 = Reserved
Speaker Mode Select
0 = Class D mode
1 = Class AB mode
DESCRIPTION
PP, Rev 3.0, April 2009
Pre-Production
50