CS42L51 Datasheet, PDF (33/83 Pages) Cirrus Logic – Low Power, Stereo CODEC with Headphone Amp

CS42L51
4.4 Analog Outputs
AOUTA and AOUTB are the ground-centered line or headphone outputs. Various signal processing options
are available, including digital mixes with the ADC signal and an internal Beep Generator. The desired path
to the DAC must be selected using the DATA_SEL[1:0] bits.
Software
Controls:
“DAC Control (Address 09h)” on page 55.
INPUTS FROM ADCA
and ADCB
SIGNAL PROCESSING ENGINE (SPE)
MUTE_ADCMIXA
MUTE_ADCMIXB
ADCMIXA_VOL[6:0]
ADCMIXB_VOL[6:0]
+12dB/-51.5dB
0.5dB steps
VOL
MUTE_PCMMIXA
MUTE_PCMMIXB
PCMMIXA_VOL[6:0]
DEEMPH ^{PCMMIXB_VOL[6:0]}
+12dB/-51.5dB
0.5dB steps
PCMA[1:0]
PCMB[1:0]
ADCA[1:0]
ADCB[1:0]
Demph
VOL
Channel
Swap
OUTA_VOL[7:0]
OUTB_VOL[7:0]
+12dB/-102dB
0.5dB steps
Chnl Vol.
Settings
Channel
Swap
ΣΣ
VOL
BPVOL[4:0]
0dB/-50dB
2.0dB steps
VOL
DAC_SZC[1:0]
DACA_MUTE
DACB_MUTE
INV_DACA
INV_DACB
DAC_SNGVOL
AMUTE
ARATE[7:0]
RRATE[7:0]
MAX[2:0]
MIN[2:0]
LIM_SRDIS
LIM_ZCDIS
LIMIT_EN
Limiter
TC_EN
Peak
Detect
Bass/
Treble/
Control
BASS_CF[1:0]
TREB_CF[1:0]
BASS[3:0]
TREB[3:0]
+12.0dB/-10.5dB
1.5dB steps
DATA_SEL[1:0]
PDN_DACA
PDN_DACB
10
Switched
01
Capacitor DAC
and Filter
00
HP_GAIN[2:0]
Headphone
Amp - GND
Centered
Charge
Pump
Left/Right
HP Out
CHRG_FREQ[3:0]
4.4.1
Digital Mix to ADC
Serial Interface
OFFTIME[2:0]
ONTIME[3:0]
FREQ[3:0]
REPEAT
BEEP
Beep
Generator
Figure 14. Output Architecture
De-Emphasis Filter
The CODEC includes on-chip digital de-emphasis optimized for a sample rate of 44.1 kHz. The filter re-
sponse is shown in Figure 15. The de-emphasis feature is included to accommodate audio recordings
that utilize 50/15 µs pre-emphasis equalization as a means of noise reduction. De-emphasis is only avail-
able in Single Speed Mode.
Software
Controls:
Hardware
Control:
“DAC Control (Address 09h)” on page 55.
Pin
Setting
“DEM” pin 4. LO
HI
Selection
No De-Emphasis
De-Emphasis Applied
Gain
dB
0dB
T1=50 µs
-10dB
T2 = 15 µs
F1
3.183 kHz
F2 Frequency
10.61 kHz
Figure 15. De-Emphasis Curve
DS679A2
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