TDA8920BJ PHILIPS [NXP Semiconductors], TDA8920BJ Datasheet - Page 16

• Manufacturer Part Number: TDA8920BJ
• Description: 2 X 100 W class-D power amplifier
• Manufacturer: PHILIPS [NXP Semiconductors]

Philips Semiconductors
9397 750 13356
Preliminary data sheet
13.2 MODE pin
13.3 Output power estimation
13.4 External clock
I
I
For pop-noise free start-up an RC time-constant must be applied on the MODE pin. The
bias-current setting of the VI-converter input is directly related to the voltage on the MODE
pin. In turn the bias-current setting of the VI converters is directly related to the DC output
offset voltage. Thus a slow dV/dt on the MODE pin results in a slow dV/dt for the DC
output offset voltage, resulting in pop-noise free start-up. A time-constant of 500 ms is
sufficient to guarantee pop-noise free start-up (see also
The achievable output powers in several applications (SE and BTL) can be estimated
using the following expressions:
SE:
P
Maximum current (internally limited to 8 A):
BTL:
Maximum current (internally limited to 8 A):
Variables:
When using an external clock the following accuracy of the duty cycle of the external clock
has to be taken into account: 47.5 % < < 52.5 %.
o peak
o peak
P
o 1%
R
f
t
V
P
P
P
o 1%
osc
min
P
o(1%)
o(10%)
o(10%)
L
= load impedance
= single-sided supply voltage (so, if supply is 30 V symmetrical, then V
= oscillator frequency
= minimum pulse width (typical 150 ns)
=
=
=
=
= output power just at clipping
= output power at THD = 10 %
= 1.24
---------------------------------------------------------------------------------------- -
V
----------------------------------------------------- -
2V
-------------------------------------------------------- -
------------------- -
R
-------------------------------------------------------------------------------------------- -
------------------- -
R
P
L
R
L
p
+
R
L
+
0.4
L
1 t
0.8
R
R
1 t
P
–
L
L
–
o(1%)
+
min
+
V
0.4
min
2V
Rev. 01 — 1 October 2004
0.8
P
2
.
P
2
f
1 t
R
osc
f
osc
L
–
R
1 t
L
–
min
min
f
osc
f
osc
2
2
2
Figure
100 W class-D power amplifier
© Koninklijke Philips Electronics N.V. 2004. All rights reserved.
4,
5
TDA8920B
and 7).
P
= 30 V)
16 of 34
(1)
(2)
(3)
(4)