TDA8594 NXP Semiconductors, TDA8594 Datasheet - Page 11

• Manufacturer Part Number: TDA8594
• Description: The TDA8594 is a complementary quad Bridge Tied Load (BTL) audio power amplifiermade in BCDMOS technology
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA8594_2
Product data sheet
Fig 6. Start-up and shut-down timing in legacy mode
V
DIAG
STB
SVR
amplifier
output
P
standby
mute
on
7.10 Engine start and low voltage operation
7.9 Power-on reset and supply voltage spikes
If in I
I
are reset, the amplifier is switched off and the DIAG pin is pulled LOW to indicate that a
power-on reset has occurred (bit DB2[D7]). When IB1[D0] is set, the power-on flag is
reset, the DIAG pin will be released and the amplifier will start up.
In legacy mode a supply voltage drop below 5 V will switch off the amplifier and the DIAG
pin will not be pulled LOW.
The DC output voltage of the amplifier (V
related to the voltage on the SVR pin (see
connected on the SVR pin to suppress the ripple on the power supply.
If the supply voltage drops, for instance, during an engine start, the output follows slowly
due to the SVR capacitor. The headroom voltage is the voltage needed for good operation
of the amplifier and is defined as V
becomes lower than the headroom protection threshold of 1.6 V, the headroom protection
is activated to prevent pop noise at the output. This protection first activates the fast mute
and then discharges the capacitors on the SVR and ACGND pins to generate more
headroom for the amplifier (see
2
C-bus latches cannot be guaranteed and the power-on reset will be activated. All latches
t
d(mute_off)
2
C-bus mode the supply voltage drops below 5 V (see
t
amp_on
Rev. 02 — 11 December 2007
t
d(soft_mute)
Figure
hr
soft
mute
= V
8).
P
t
O
d(mute_on)
) is set to half of the supply voltage and is
Figure
I
2
V
C-bus controlled 4
O
(see
7; V
Figure
O
= V
SVR
Figure
7). If the headroom voltage
1.4 V). A capacitor is
t
9), the content of the
d(fast_mute)
50 W power amplifier
TDA8594
© NXP B.V. 2007. All rights reserved.
fast
mute
t
off
001aad171
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