3 analog outputs, Figure 8. output architecture, 1 de-emphasis filter – Cirrus Logic CS43L21 User Manual

Page 24: Figure 8.output architecture, Cs43l21, No de-emphasis, De-emphasis applied

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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]

PC

M Ser

ial Inter

face

OFFTIME[2:0]

ONTIME[3:0]

FREQ[3:0]

REPEAT

BEEP

Channel

Swap

Figure 8. Output Architecture

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