TDA8950 NXP Semiconductors, TDA8950 Datasheet - Page 18

• Manufacturer Part Number: TDA8950
• Description: The TDA8950 is a high-efficiency Class D audio power amplifier
• Manufacturer: NXP Semiconductors

NXP Semiconductors
TDA8950_2
Product data sheet
13.3.2 Bridge-Tied Load (BTL)
13.4 External clock
Maximum output power:
Maximum output current internally limited to 9.2 A:
Where:
Remark: Note that I
of 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.
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)
sL
: load impedance
: single-sided supply voltage or 0.5
: oscillator frequency
: series impedance of the filter coil
=
=
: minimum pulse width (typical 150 ns, temperature dependent)
------------------------------------------------------------------------------------------ -
R
---------------------------------------------------------------------------------------------------------------------------------------------------------- -
: output power at the onset of clipping
: low-side R
------------------------------------------------------------------ - 2V
R
L
: high-side R
350 kHz = 700 kHz).
L
+
2V
+
OSC
R
P
R
DSon hs
DSon hs
o(peak)
must be removed when using an external oscillator.
1 t
Rev. 02 — 11 June 2009
–
DSson
R
DSon
L
w min
should be less than 9.2 A; see
+
+
R
R
of power stage output DMOS (temperature dependent)
DSon ls
of power stage output DMOS (temperature dependent)
DSon ls
0.5 f
osc
2R
+
2R
L
P
sL
(V
DD
1 t
+ V
–
w min
OSC
2
SS
)
, connected between pin OSC
150 W class-D power amplifier
Section
0.5 f
osc
8.3.2. I
2
TDA8950
© NXP B.V. 2009. All rights reserved.
o(peak)
is the sum
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