WM8962B Datasheet, PDF (122/295 Pages) Wolfson Microelectronics plc – Ultra-Low Power Stereo CODEC with Audio Enhancement DSP, 1W Stereo Class D Speaker Drivers and Ground Referenced Headphone Drivers

122
WM8962
SPKOUTLP
SPKOUTLN
8Ω
SPKOUTRN
SPKOUTRP
8Ω
SPKOUTLP
SPKOUTLN
SPKOUTRN
SPKOUTRP
4Ω
STEREO SPEAKER CONFIGURATION
SPK_MONO = 0, Class D driving into 8Ω loads
MONO SPEAKER CONFIGURATION
SPK_MONO = 1, Class D driving into 4Ω load
Figure 34 Mono and Stereo Speaker Output Configuration
Eight levels of AC signal boost are provided in order to deliver maximum output power for many
commonly-used SPKVDD/AVDD combinations. The AC boost levels from 0dB to +12dB are selected
using register bit CLASSD_VOL, which boosts left and right channels equally. To prevent pop noise,
CLASSD_VOL should not be modified while the speaker outputs are enabled. Figure 35 illustrates
the speaker outputs and gain/boost options available.
Ultra-low leakage and high PSRR allow the speaker supply SPKVDD to be directly connected to a
lithium battery. Note that an appropriate SPKVDD supply voltage must be provided to prevent
waveform clipping when speaker boost is used.
DC gain is applied automatically with a shift from VMID to SPKVDD/2. This provides optimum signal
swing for maximum output power.
AVDD
SPKOUTL_VOL[6:0]
-73dB to +6dB,
1dB steps
AGND
AVDD
SPKOUTR_VOL[6:0]
-73dB to +6dB,
1dB steps
AGND
SPKVDD
CLASSD_VOL[2:0]
SPKOUTLP
SPKOUTLN
SPKGND
SPKVDD
CLASSD_VOL[2:0]
SPKOUTRP
SPKOUTRN
SPKGND
CLASSD_VOL
000 = 1.00x (+0dB)
001 = 1.19x (+1.5dB)
010 = 1.41x (+3.0dB)
011 = 1.68x (+4.5dB)
100 = 2.00x (+6.0dB)
101 = 2.37x (+7.5dB)
110 = 2.81x (+9.0dB)
111 = 3.98x (+12.0dB)
AVDD
VMID
Figure 35 Speaker Output Configuration and AC Boost Operation
SPKVDD
Signal x BOOST
SPKVDD/2
Signal x BOOST is
automatically
centred around
SPKVDD/2
AGND
Rev 4.3