TDA8922B
Philips Semiconductors
2 × 50 W class-D power amplifier
Table 4:
Overview protections TDA8922B
Protection name
Complete shut-down Restart directly
Restart every 100 ms
OTP
OCP
WP
Y
Y [1]
Y[2]
Y
N[1]
N[2]
N
N[2]
Y[3]
Y
UVP
OVP
UBP
N
Y
Y
Y
N
Y
N
Y
[1] Hysteresis of 20 degrees will influence restart timing depending on heatsink size.
[2] Only complete shut-down of amplifier if short-circuit impedance is below threshold of 1 Ω. In all other cases
current limiting: resulting in clipping output signal.
[3] Fault condition detected during (every) transition between standby-to-mute and during restart after
activation of OCP (short to one of the supply lines).
8.4 Differential audio inputs
For a high common mode rejection ratio and a maximum of flexibility in the application, the
audio inputs are fully differential. By connecting the inputs anti-parallel the phase of one of
the channels can be inverted, so that a load can be connected between the two output
filters. In this case the system operates as a mono BTL amplifier and with the same
loudspeaker impedance an approximately four times higher output power can be
obtained.
The input configuration for a mono BTL application is illustrated in Figure 6.
In the stereo single-ended configuration it is also 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.
OUT1
IN1P
IN1M
V
SGND
in
IN2P
IN2M
OUT2
power stage
mbl466
Fig 6. Input configuration for mono BTL application.
9397 750 13357
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
Preliminary data sheet
Rev. 01 — 1 October 2004
10 of 32
NXP [ NXP ]
