AS3543 High End Stereo Audio Codec with System Power Management0 pages

AS3543

Data Sheet, Strictly Confidential

H i g h E n d St e r e o A u d i o C o d e c w i t h S y s t e m P M U

1 General Description

2 Key Features

The AS3543 is an ultra low power stereo audio codec
and is designed for Portable Digital Audio Applications.

Audio

It allows high-end quality playback with up to 100dBA
SNR and recording in FM quality. With one microphone
(including pre-amplifier and supply for an electret microphone) and two line inputs, it allows connecting a variety
of audio inputs. The different audio signals can be mixed
via a 6-channel mixer and fed to either a headphone output for 16 /32 headsets or a line output. Both outputs
have a ground noise cancellation to use it e.g. in car
docking stations. The audio outputs have also an auto
fading implemented which performs the fade-in, fadeout as well as the transition between specific volume
levels automatically with an selectable timing.

Audio power consumption:

Further the device offers advanced power management
functions. All necessary ICs and peripherals in a Digital
Audio Player are supplied by the AS3543. It features 2
DCDC converters for core and memory/periphery supply
as well as 4 LDOs. Both DCDC converter feature DVM
(dynamic voltage management) with an selectable timing for the voltage stepping. The different regulated supply voltages are programmable via the serial control
interface.
The step-up converter for the backlight can operate up
to 15V (with an external transistor even higher) in voltage and current control mode. An internal voltage protection is limiting the output voltage in the case of
external component failures. 2 high voltage current sinks
can be used to operate two, if needed also unbalanced,
LED strings. An automatic dimming function allows a
logarithmic on/off of the backlight with selectable timing.
AS3543 also contains a Li-Ion battery charger with constant current, constant voltage and trickle charging. The
maximum charging current is 460mA. An integrated battery switch is separating the battery during charging or
whenever an external power supply is present. With this
switch it is also possible to operate with no or deeply discharged batteries.
The AS3543 has an on-chip, phase locked loop (PLL)
which generates the needed internal CODEC master
clock. I2S Frame and shift-clock have to be applied from
the processor for playback and recording.

- 5mW: 96dB DAC to Headphone @ 1.8V, 32Ω
- 7mW: 100dB DAC to Headphone @ 2.9V, 32Ω

Sigma Delta Converters
DAC
- 98dB SNR ('A' weighted) @ 1.7V
- 102dB SNR ('A' weighted) @ 2.9V
ADC
- 85dB SNR ('A' weighted) @ 1.7V
Sampling Frequency
- DAC: 8-96kHz
- ADC: 8-24kHz

High Efficiency Headphone Amplifier
volume control via serial interface
32 steps @1.5dB and MUTE
2x12mW @16Ω driver capability@ 1.8V supply
THD -74dB @16Ω; 1.8V
2x40mW @16Ω driver capability@ 3.6V supply
THD -77dB @16Ω; 3.6V
headphone and over-current detection
phantom ground eliminates large capacitors
ground noise cancellation

Line Output
volume control via serial interface
32 steps @1.5dB and MUTE
0.6Vp @10kΩ, 1.8V
ground noise cancellation

Further the AS3543 has an independent 32kHz real time
clock (RTC) on chip which allows a complete power
down of the system CPU while only consuming less than
1µA. An internal switch automatically switches between
the RTC backup-battery and main battery supply.
The single supply voltage may vary from 2.7V to 5.5V.

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Revision 1.10

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