TDA8929T NXP Semiconductors, TDA8929T Datasheet - Page 10

• Manufacturer Part Number: TDA8929T
• Manufacturer: NXP Semiconductors

Specifications of TDA8929T

• Lead Free Status / Rohs Status: Compliant

Philips Semiconductors
8.3.3
During the start-up sequence, when pin MODE is switched
from standby to mute, the condition at the output terminals
of the power stage are checked. These are the same lines
as the feedback inputs of the controller. In the event of a
short-circuit of one of the output terminals to V
the start-up procedure is interrupted and the system waits
for non-shorted outputs. Because the test is done before
enabling the power stages, no large currents will flow in the
event of a short-circuit. This system protects against
short-circuits at both sides of the output filter to both supply
lines. When there is a short-circuit from the outputs of the
power stage to one of the supply lines, before the
demodulation filter, it will also be detected by the start-up
safety test. Practical use from this test feature can be
found in detection of short-circuits on the printed-circuit
board.
Remark: this test is only operational prior to or during the
start-up sequence, and not during normal operating.
2001 Dec 11
handbook, full pagewidth
Controller class-D audio amplifier
S
TART
-
UP SAFETY TEST
V i
IN1
IN1
IN2
IN2
CONTROLLER
TDA8929T
Fig.5 Mono BTL application.
DD
or V
REL1
REL2
SW1
SW2
EN1
EN2
SS
10
8.4
For a high common mode rejection and a maximum
flexibility of application, the audio inputs are fully
differential. By connecting the inputs anti-parallel the
phase of one of the channels is inverted, so that a load can
be connected between the two output filters. In this case
the system operates as a mono BTL amplifier (see Fig.5).
Also in the stereo single-ended configuration it is
recommended to connect the two differential inputs in
anti-phase. This has advantages for the current handling
of the power supply at low signal frequencies.
POWER
STAGE
Differential audio inputs
OUT1
OUT2
SGND
MGW185
Preliminary specification
TDA8929T