TDA1305 Philips Semiconductors, TDA1305 Datasheet - Page 9

• Manufacturer Part Number: TDA1305
• Description: Stereo 1fs data input up-sampling filter with bitstream continuous dual DAC BCC-DAC2
• Manufacturer: Philips Semiconductors

Philips Semiconductors
Noise shaper
In the normal speed mode the 2nd order digital noise
shaper operates at 96f
(f
(f
shifts in-band quantization noise to frequencies well above
the audio band. This noise shaping technique used in
combination with a special data coding enables extremely
high signal-to-noise ratios to be achieved. The noise
shaper outputs a 5-bit pulse duration modulation (PDM)
bitstream signal to the DAC.
Continuous calibration DAC
The dual 5-bit DAC uses the continuous calibration
technique. This method, based on charge storage,
involves exact duplication of a single reference current
source. In the TDA1305T, 32 such current sources plus
1 spare source are continuously calibrated. The spare
source is included to allow continuous converter operation.
The DAC receives a 5-bit data bitstream from the noise
shaper. This data is then converted so that only small
currents are switched to the output during digital silence
LIMITING VALUES
In accordance with the Absolute Maximum Rating System (IEC 134).
Notes
1. Human body model; C = 100 pF, R = 1500 , V = 2000 V, 3 pulses positive and 3 pulses negative.
2. Machine model; C = 200 pF, R = 10 , L = 0.5 H.
THERMAL CHARACTERISTICS
1995 Dec 08
V
V
V
T
T
T
V
R
sys
sys
SYMBOL
SYMBOL
xtal
stg
amb
DDD
DDA
DDO
es
th j-a
Stereo 1fs data input up-sampling filter with
bitstream continuous dual DAC (BCC-DAC2)
= 256f
= 384f
s
s
). The digital noise shaper operates at 48f
) or 64f
digital supply voltage
analog supply voltage
operational amplifier supply voltage
maximum crystal temperature
storage temperature
ambient operating temperature
electrostatic handling
thermal resistance from junction to ambient in free air
s
(f
sys
s
(f
= 256f
sys
PARAMETER
= 384f
s
) in double-speed mode. It
s
) or 128f
s
PARAMETER
s
note 1
note 2
9
(input 00000H). Using this technique extremely high
signal-to-noise performance is achieved.
Operational amplifiers
High precision, low-noise amplifiers together with the
internal conversion resistors R
the converter output current to a voltage capable of driving
a line output. This voltage is available at VOL and VOR
(1.5 V RMS typical).
Connecting external capacitors CEXT1 and CEXT2
between FILTCL and VOL and between FILTCR and VOR
respectively provides the required 1st order post filtering
for the left and right channels (see Fig.1). The
combinations of R
CEXT2 determine the 1st order fall-off frequencies.
Internal reference circuitry
Internal reference circuitry ensures that the output voltage
signal is proportional to the supply voltage, thereby
maintaining maximum dynamic range for supply voltages
from 3.4 to 5.5 V and making the circuit also suitable for
battery-powered applications.
CONDITIONS
CONV1
65
30
2000
200
MIN.
with CEXT1 and R
CONV1
Preliminary specification
7.0
7.0
7.0
+150
+150
+85
+2000
+200
VALUE
MAX.
and R
75
TDA1305T
CONV2
CONV2
V
V
V
V
V
C
C
C
UNIT
UNIT
convert
K/W
with