TDA8922C NXP Semiconductors, TDA8922C Datasheet - Page 18

• Manufacturer Part Number: TDA8922C
• Description: The TDA8922C is a high-efficiency Class D audio power amplifier
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA8922C_1
Product data sheet
13.3.2 Bridge-Tied Load (BTL)
13.4 External clock
13.5 Heatsink requirements
Maximum output power:
Maximum output current internally limited to 6 A:
Where:
Remark: Note that I
the current through the load and the ripple current. The value of the ripple current is
dependent on the coil inductance and the voltage drop across the coil.
To ensure duty cycle-independent operation, the external clock frequency is divided by
two internally. The external clock frequency is therefore twice the internal clock frequency
(typically 2
If several Class D amplifiers are used in a single application, it is recommended that all
the devices run at the same switching frequency. This can be achieved by connecting the
OSC pins together and feeding them from an external oscillator. When using an external
oscillator, it is necessary to force pin OSC to a DC level above SGND. This disables the
internal oscillator and causes the PWM to switch at half the external clock frequency.
The internal oscillator requires an external resistor R
and pin VSSA. R
The noise generated by the internal oscillator is supply voltage dependent. An external
low-noise oscillator is recommended for low-noise applications running at high supply
voltages.
An external heatsink must be connected to the TDA8922C.
P
I
o peak
•
•
•
•
•
•
•
•
o 0.5%
P
R
R
R
R
V
t
f
w(min)
osc
o(0.5 %)
P
L
DSon(hs)
DSon(ls)
s(L)
: load impedance
: single-sided supply voltage or 0.5
: oscillator frequency
: series impedance of the filter coil
=
=
: minimum pulse width (typical 100 ns, temperature dependent)
---------------------------------------------------------------------------------------------- -
R
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- -
: output power at the onset of clipping
V
: low-side R
------------------------------------------------------------------ -
R
L
: high-side R
350 kHz = 700 kHz).
DD
L
+
+
OSC
R
–
R
DSon hs
V
DSon hs
o(peak)
SS
Rev. 01 — 7 September 2009
must be removed when using an external oscillator.
DSon
R
DSon
L
should be less than 6 A; see
1 t
+
+
–
R
of power stage output DMOS (temperature dependent)
R
DSon ls
of power stage output DMOS (temperature dependent)
DSon ls
w min
0.5 f
+
2R
V
2R
DD
osc
s L
(V
L
DD
–
V
+ V
SS
OSC
SS
2
Section
)
1 t
, connected between pin OSC
–
75 W class-D power amplifier
w min
8.3.2. I
TDA8922C
0.5 f
o(peak)
© NXP B.V. 2009. All rights reserved.
osc
is the sum of
2
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