UDA1344 PHILIPS [NXP Semiconductors], UDA1344 Datasheet - Page 7

• Manufacturer Part Number: UDA1344
• Description: Low-voltage low-power stereo audio CODEC with DSP features
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
Mute (ADC)
On recovery from power-down or switching on of the
system clock, the serial data output on pin DATAO is held
at LOW level until valid data is available from the
decimation filter. This time depends on whether the
DC-cancellation filter is selected:
Interpolation filter (DAC)
The digital filter interpolates from 1f
a cascade of a recursive filter and an FIR filter.
Table 4 Interpolation filter characteristics
Noise shaper (DAC)
The 3rd-order noise shaper operates at 128f
in-band quantization noise to frequencies well above the
audio band. This noise shaping technique enables high
signal-to-noise ratios to be achieved. The noise shaper
output is converted into an analog signal using a Filter
Stream Digital-to-Analog Converter (FSDAC).
Filter stream DAC
The FSDAC is a semi-digital reconstruction filter that
converts the 1-bit data stream of the noise shaper to an
analog output voltage. The filter coefficients are
implemented as current sources and are summed at
virtual ground of the output operational amplifier. In this
way very high signal-to-noise performance and low clock
jitter sensitivity is achieved. A post-filter is not needed due
to the inherent filter function of the DAC. On-board
amplifiers convert the FSDAC output current to an output
voltage signal capable of driving a line output.
The output voltage of the FSDAC scales proportionally
with the power supply voltage.
2000 Feb 04
Pass-band ripple
Stop band
Dynamic range
Gain
DC cancel off:
DC cancel on:
Low-voltage low-power stereo audio
CODEC with DSP features
t
t
=
=
1024
------------ -
12288
--------------- -
ITEM
f
s
f
s
; t = 23.2 ms at f
; t = 279 ms at f
CONDITIONS
0
0
>0.55f
DC
0.45f
0.45f
s
s
= 44.1 kHz
= 44.1 kHz.
s
s
s
s
to 128f
VALUE (dB)
s
s
by means of
. It shifts
108
0.03
3.5
50
7
Multiple format input/output interface
The UDA1344TS supports the following data input/output
formats:
The formats are illustrated in Fig.3. Left and right
data-channel words are time multiplexed.
Control mode selection
The UDA1344TS can be used under L3 microcontroller
interface control or static pin control. The mode can be set
via the mode control pins MC1 and MC2 (see Table 5).
Table 5 Mode control pins
Important: in the L3 mode the UDA1344TS is completely
pin and function compatible with the UDA1340M.
I
MSB-justified serial format with data word length of up to
20 bits
LSB-justified serial format with data word lengths of
16, 18 or 20 bits (in L3 mode only)
Combined data formats:
– L3 mode: MSB-justified data output and
– Static pin mode: MSB-justified data output and
2
S-bus format with data word length of up to 20 bits
PIN MC2
LSB-justified 16, 18 and 20 bits data input
LSB-justified 16 and 20 bits data input.
HIGH
HIGH
LOW
LOW
PIN MC1
HIGH
HIGH
LOW
LOW
Preliminary specification
UDA1344TS
L3 mode
Test mode
Static pin mode
MODE