uda1334ts NXP Semiconductors, uda1334ts Datasheet - Page 8

• Manufacturer Part Number: uda1334ts
• Description: Low Power Audio Dac
• Manufacturer: NXP Semiconductors

Philips Semiconductors
8.4
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. No post-filter is 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 proportional with
the power supply voltage.
8.5
The UDA1334TS has an internal Power-on reset circuit
(see Fig.3) which resets the test control block.
The reset time (see Fig.4) is determined by an external
capacitor which is connected between pin V
ground. The reset time should be at least 1 s for
V
will be reset again for V
During the reset time the system clock should be running.
2000 Oct 25
handbook, halfpage
ref(DAC)
Low power audio DAC
Filter stream DAC
Power-on reset
< 1.25 V. When V
3.0 V
V ref(DAC)
Fig.3 Power-on reset circuit.
C1
10 F
V DDA
13
12
ref(DAC)
DDA
50 k
50 k
UDA1334TS
is switched off, the device
< 0.75 V.
CIRCUIT
RESET
MGU248
ref(DAC)
and
8
handbook, halfpage
V ref(DAC)
V DDD
V DDA
(V)
(V)
(V)
1.25
0.75
1.5
1.5
1.5
3.0
3.0
3.0
0
0
0
Fig.4 Power-on reset timing.
1 s
Product specification
UDA1334TS
MGL984
t
t
t