AS3543 Datasheet, PDF (1/4 Pages) ams AG – High End Stereo Audio Codec with System PMU

AS3543
Preliminary Product Brief
High End Stereo Audio Codec with System PMU
General Description
The AS3543 is an ultra low power stereo audio codec
and is designed for Portable Digital Audio Applications.
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 micro-
phone) 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 out-
put 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, fade-
out as well as the transition between specific volume
levels automatically with an selectable timing.
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 tim-
ing for the voltage stepping. The different regulated sup-
ply voltages are programmable via the serial control
interface.
The step-up converter for the backlight can operate up
to 25V (with an external transistor even higher) in volt-
age and current control mode. An internal voltage pro-
tection 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 con-
stant current, constant voltage and trickle charging. The
maximum charging current is 460mA. An integrated bat-
tery 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 dis-
charged 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.
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 (2.4V) to
5.5V.
Key Features
Audio
Audio power consumption:
- 5mW: 96dB DAC to Headphone @ 1.8V, 32Ω
- 7mW: 100dB DAC to Headphone @ 2.9V, 32Ω
Sigma Delta Converters
DAC
- 98dB SNR ('A' weighted) @ 1.8V
- 102dB SNR ('A' weighted) @ 2.9V
ADC
- 83dB SNR ('A' weighted) @ 1.8V
Sampling Frequency
- DAC: 8-48kHz
- ADC: 8-24kHz
High Efficiency Headphone Amplifier
volume control via serial interface
32 steps @1.5dB and MUTE
2x12mW @16 driver capability@ 1.8V supply
THD -74dB @16Ω; 1.8V
2x40mW @16 driver capability@ 2.9V supply
THD -77dB @16Ω; 2.9V
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
ground noise cancellation
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Revision 0.12
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