TDA8920TH NXP Semiconductors, TDA8920TH Datasheet - Page 16

• Manufacturer Part Number: TDA8920TH
• Manufacturer: NXP Semiconductors

Specifications of TDA8920TH

• Operational Class: Class-D
• Output Power (typ): 140x1@8Ohm/80x2@4OhmW
• Audio Amplifier Function: Speaker
• Total Harmonic Distortion: 0.02@8Ohm@1W%
• Single Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (typ): ±25V
• Power Supply Requirement: Dual
• Rail/rail I/o Type: No
• Single Supply Voltage (min): Not RequiredV
• Single Supply Voltage (max): Not RequiredV
• Dual Supply Voltage (min): ±12.5V
• Dual Supply Voltage (max): ±30V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Mounting: Surface Mount
• Pin Count: 24
• Lead Free Status / Rohs Status: Compliant

Philips Semiconductors
16 APPLICATION INFORMATION
16.1
When using the system in the mono BTL application (for
more output power), the inputs of both channels must be
connected in parallel; the phase of one of the inputs must
be inverted; see Fig.5. In principle the loudspeaker can be
connected between the outputs of the two single-ended
demodulation filters.
16.2
For correct operation the switching voltage at the mode pin
should be debounced. If the mode pin is driven by a
mechanical switch an appropriate debouncing low-pass
filter should be used. If the mode pin is driven by an
electronic circuit or microcontroller then it should remain at
the mute voltage level for at least 100 ms before switching
back to the standby voltage level.
16.3
The output power in several applications (SE and BTL)
can be estimated using the following expressions:
SE:
Maximum current:
should not exceed 7.5 A.
2002 Sep 25
handbook, full pagewidth
2
P
out_1%
BTL application
MODE pin
Output power estimation
80 W class-D power amplifier
=
----------------------------------------------------------------------------------------- -
---------------------
R
L
I
R
+
out^
120 pF
L
9.1 k
0.6
=
RCTC
V
---------------------------------------------------- -
V
CTC
RTC
P
P
2 R
1
2
3
R
CLOCK
1 t
1 t
L
–
11
13
L
–
+
0
min
min
0.6
10
0
f
f
osc
osc
Fig.7 External oscillator circuit.
4
8
HEF4047BT
ASTAB
TRIGGER
2
5
9
ASTAB
MR
16
BTL:
Maximum current:
should not exceed 7.5 A.
Legend:
16.4
The minimum required symmetrical supply voltage for
external clock application is 15 V (equally the minimum
asymmetrical supply for applications with an external clock
is 30 V).
When using an external clock the following accuracy of the
duty cycle of the external clock has to be taken into
account; 47.5% < DC, external clock < 52.5%.
A possible solution for an external clock oscillator circuit is
illustrated in Fig.7.
R
f
t
V
symmetrical
P
P
P
osc
min
12
P
out_1%
out_10%
out_10%
L
6
RETRIGGER
= load impedance
= single-sided supply voltage (so if supply 30 V
P
TRIGGER
= oscillator frequency
= minimum pulse width (typical 190 ns)
External clock
out_1%
14
7
= output power just at clipping
V DD
V SS
= output power at THD = 10%
= 1.25
=
---------------------------------------------------------------------------------------------
360 kHz 320 kHz
---------------------
R
V
220
nF
I
P
L
out^
P
R
+
= 30 V)
out_1%
V DDA
L
GND
1.2
=
2 k
5.6 V
2V
-------------------------------------------------------- -
.
MBL468
2V
P
2 R
P
R
1 t
HOP
4.3 V
L
1 t
–
+
L
Product specification
–
min
1.2
min
TDA8920
f
osc
f
osc
2