Instruction Manual
24 DS723F1
CS43L21
4.3 Analog Outputs
AOUTA and AOUTB are the ground-centered line or headphone outputs. Various signal processing options
are available, including an internal Beep Generator. The desired path to the DAC must be selected using
the DATA_SEL[1:0] bits.
4.3.1 De-Emphasis Filter
The device includes on-chip digital de-emphasis optimized for a sample rate of 44.1 kHz. The filter re-
sponse is shown in Figure 9. The de-emphasis feature is included to accommodate audio recordings that
utilize 50/15 s pre-emphasis equalization as a means of noise reduction. De-emphasis is only available
in Single-Speed Mode. 
Software 
Controls:
 “DAC Control (Address 09h)” on page 43.
Software 
Controls:
“DAC Control (Address 09h)” on page 43.
Hardware 
Control:
Pin
Setting Selection
“DEM” pin 4. 
LO
No De-Emphasis
HI
De-Emphasis Applied 
Charge 
Pump
Left/Right 
HP Out
Switched 
Capacitor DAC 
and Filter
Headphone
Amp - GND 
Centered
PDN_DACA
PDN_DACB
DATA_SEL[1:0]
00
CHRG_FREQ[3:0]
01
HP_GAIN[2:0]
Beep 
Generator
Bass/
Treble/
Control
VOL
Peak
Detect
Limiter
Chnl Vol.
Settings
Demph
VOL
VOL
+12dB/-102dB
 0.5dB steps
OUTA_VOL[7:0]
OUTB_VOL[7:0]
+12dB/-51.5dB
 0.5dB steps
PCMMIXA_VOL[6:0]
PCMMIXB_VOL[6:0]
0dB/-50dB
 2.0dB steps
BPVOL[4:0]
MUTE_PCMMIXA
MUTE_PCMMIXB
DEEMPH
BASS[3:0]
TREB[3:0]
+12.0dB/-10.5dB
 1.5dB steps
BASS_CF[1:0]
TREB_CF[1:0]
TC_EN
SIGNAL PROCESSING ENGINE (SPE)
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
PCMA[1:0]
PCMB[1:0]
PCM Serial Interface
OFFTIME[2:0]
ONTIME[3:0]
FREQ[3:0]
REPEAT
BEEP
Channel 
Swap
Figure 8. Output Architecture










