wm9001 Wolfson Microelectronics plc, wm9001 Datasheet - Page 17

• Manufacturer Part Number: wm9001
• Description: 1w Dual-mode Class Ab/d Speaker Driver
• Manufacturer: Wolfson Microelectronics plc

Pre-Production
SPEAKER DRIVER MODE SELECT
SIGNAL BOOST CONTROL
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The speaker outputs operate in a BTL configuration, in either class AB or class D mode. The speaker
driver mode is selected using the CDMODE pin.
Table 4 Class AB / D Mode Control
Six levels of signal boost are available to provide maximum output power for many commonly used
SPKVDD/AVDD combinations. These boost options are available in class AB and class D modes.
AC and DC gain levels from 1.0x to 1.8x are selected using the BSEL[2:0] input pins. Note that
ACGAIN = DCGAIN for all settings.
An appropriate SPKVDD supply voltage must be provided to prevent waveform clipping when signal
boost is used.
Figure 7 Signal Boost Operation
Table 5 Signal Boost Control
To prevent pop noise, the BSEL[2:0] settings should not be modified while the speaker outputs are
enabled. Note that ACGAIN = DCGAIN for all settings.
12,11,10
PIN
PIN
7
BSEL[2:0]
CDMODE
NAME
NAME
Signal Boost Control
000 = 1.00x boost (+0dB)
001 = 1.27x boost (+2.1dB)
010 = 1.40x boost (+2.9dB)
011 = 1.52x boost (+3.6dB)
100 = 1.67x boost (+4.5dB)
101 = 1.8x boost (+5.1dB)
110 = Reserved
111 = Reserved
Class AB/D Mode Select
0 = Class D mode
1 = Class AB mode
DESCRIPTION
DESCRIPTION
PP, June 2009, Rev 3.2
WM9001
17