Philips TDA1563Q - Manual (Page 24)

2000 Feb 09 24
Philips Semiconductors Product specification
2
×
25 W high efficiency car radio power
amplifier
TDA1563Q
Advantages of high efficiency
•
Power conversion improvement (power supply)
Usually, the fact that the reduction of dissipation is
directly related to supply current reduction is neglected.
One advantage is less voltage drop in the whole supply
chain. Another advantage is less stress for the coil in the
supply line. Even the adapter or supply circuit remains
cooler than before as a result of the reduced heat
dissipation in the whole chain because more supply
current will be converted to output power.
•
Power dissipation reduction
This is the best known advantage of high efficiency
amplifiers.
•
Heatsink size reduction
The heatsink size of a conventional amplifier may be
reduced by approximately 50% at V
P
= 14.4 V when the
TDA1563Q is used. In this case, the maximum heatsink
temperature will remain the same.
•
Heatsink temperature reduction
The power dissipation and the thermal resistance of the
heatsink determine the heatsink temperature rise. When
the same heatsink size is used as in a conventional
amplifier, the maximum heatsink temperature
decreases and also the maximum junction temperature,
which extends the life of this semiconductor device.
The maximum dissipation with music-like input signals
decreases by 40%.
It is clear that the use of the TDA1563Q saves a significant
amount of energy. The maximum supply current
decreases by approximately 32%, which reduces the
dissipation in the amplifier as well in the whole supply
chain. The TDA1563Q allows a heatsink size reduction of
approximately 50% or a heatsink temperature decrease of
40% when the heatsink size is not changed.
Advantage of the concept used by the TDA1563Q
The TDA1563Q is highly efficient under all conditions,
because it uses a SE capacitor to create a non-dissipating
half supply voltage. Other concepts rely on both input
signals being the same in amplitude and phase. With the
concept of an SE capacitor, it does not matter what kind of
signal processing is done on the input signals.
For example, amplitude difference, phase shift or delays
between both input signals, or other DSP processing, have
no impact on the efficiency.
handbook, halfpage
MGS824
Supply
current
reduction of
32%
Heatsink
size
reduction of
50%
Same heatsink
size
Same junction
temperature
Heatsink
temperature
reduction of
40%
Power
dissipation
reduction of 40%
at Po = 1.6 W
VP = 14.4 V
choice
Fig.27 Heatsink design