Philips TDA8950 Product Data Sheet page 7

NXP Semiconductors
TDA8950_2
Product data sheet
To ensure the coupling capacitors at the inputs (C
the outputs start switching, a delay is inserted during the transition from Mute to Operating
mode. An overview of the start-up timing is provided in
MODE pin should be forced LOW at leaxt 100 ms before the supply lines (V
drop below 12.5 V.
V
MODE
4.2 V
2.2 V V 3 V
MODE
0 V (SGND)
V
MODE
4.2 V
2.2 V V 3 V
MODE
0 V (SGND)
1
(1) First pulse down.
4
Upper diagram: When switching from Standby to Mute, there is a delay of approximately 100 ms
before the output starts switching. The audio signal will become available once V
Operating mode level (see
pop noise-free, it is recommended that the time constant applied to pin MODE be at least 350 ms
for the transition between Mute and Operating modes.
Lower diagram: When switching directly from Standby to Operating mode, there is a delay of
100 ms before the outputs start switching. The audio signal becomes available after a second
delay of 50 ms. To start-up pop noise-free, it is recommended that the time-constant applied to pin
MODE be at least 500 ms for the transition between Standby and Operating modes.
Fig 5. Timing on mode selection input pin MODE
(1)
50 %
duty cycle
mute
standby
100 ms
50 ms
(1)
50 %
duty cycle
mute
standby
100 ms
50 ms
Table 8), but not earlier than 150 ms after switching to Mute. To start-up
Rev. 02 — 11 June 2009
TDA8950
2 150 W class-D power amplifier
in Figure 10) are fully charged before
IN
Figure 5. For proper switch-off, the
audio output
modulated PWM
operating
> 350 ms
audio output
modulated PWM
operating
> 350 ms
© NXP B.V. 2009. All rights reserved.
and V )
DDA SSA
time
time
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reaches the
MODE
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