CS42L52 Datasheet, PDF (33/82 Pages) Cirrus Logic – Low Power, Stereo CODEC w/Headphone & Speaker Amps

CS42L52
4.4.2
Referenced Control Register Location
PDN_ADCx ......................... “Power Down ADCx” on page 43
PASSTHRU ......................... “Passthru Analog” on page 52
PDN_OVRD ........................ “Power Down ADC Override” on page 43
SPKx_PDN[1:0]................... “Speaker Power Control” on page 44
Overriding the PGA Power Down
To accommodate automatic activation of the headphone amplifier when the SPK/HP_SW switch pin
changes, the CS42L52 will automatically power up the PGA whenever passthru is enabled, regardless of
the PDN_PGA setting. Refer to the table below for how this PGA power-down override functions in accord
with the state of the headphone channels. The shaded cells represent normal PGA operation when
Passthru is disabled.
PDN_PGA
0
1
PASSTHRU
x
0
1
HP Channel
x
x
OFF
ON
PGA Status
Powered UP
Powered DOWN
Powered DOWN
Powered UP
When Passthru is enabled, turning the headphone channel ON (by writing ‘11’b to HPx_PDN[1:0] or by
automatic activation of the headphone detect switch, SPK/HP_SW) will automatically disable the
PGAx_PDN in order to transmit the analog signal to the headphone.
Referenced Control Register Location
PDN_PGAx ......................... “Power Down PGAx” on page 42
PASSTHRU ......................... “Passthru Analog” on page 52
HPx_PDN[1:0]..................... “Headphone Power Control” on page 44
4.5 PWM Outputs
4.5.1 Mono Speaker Output Configuration
The CS42L52 accommodates a stereo as well as a mono speaker output configuration. In mono mode
the output drivers of each channel are connected in parallel to deliver maximum power to a 4 ohm speak-
er. Refer to the table below for pin mapping in mono configuration.
Speaker Output
Pin
SPKMONO=0
SPKMONO=1
SPKSWAP=0
SPKSWAP=1
SPKSWAP=0
SPKSWAP=1
4
SPKOUTA+
SPKOUTB+
SPKOUTA+
SPKOUTB+
6
SPKOUTA-
SPKOUTB-
SPKOUTA+
SPKOUTB+
7
SPKOUTB+
SPKOUTA+
SPKOUTA-
SPKOUTB-
9
SPKOUTB-
SPKOUTA-
SPKOUTA-
SPKOUTB-
Referenced Control Register Location
SPKMONO.......................... “Speaker MONO Control” on page 54
SPKSWAP........................... “Speaker Channel Swap” on page 54
4.5.2 VP Battery Compensation
Note:
The CS42L52 provides the option to maintain a desired power output level, independent of the VP supply.
When enabled, this feature works by monitoring the voltage on the VP supply and reducing the attenua-
tion on the speaker outputs when VP voltage levels fall.
The internal ADC that monitors the VP supply operates from the VA supply. Calculations are based on typ-
ical VA levels of 1.8 V and 2.5 V using the VPREF bits.
DS680A1
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