TS4990EKIJT STMICROELECTRONICS [STMicroelectronics], TS4990EKIJT Datasheet - Page 18

• Manufacturer Part Number: TS4990EKIJT
• Description: 1.2 W audio power amplifier with active low standby mode
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

Application information
4
4.1
4.2
4.3
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Application information
BTL configuration principle
The TS4990 is a monolithic power amplifier with a BTL output type. BTL (bridge tied load)
means that each end of the load is connected to two single-ended output amplifiers. Thus,
we have:
The output power is:
For the same power supply voltage, the output power in BTL configuration is four times
higher than the output power in single-ended configuration.
Gain in a typical application
The typical application schematics are shown in
In the flat region (no C
For the second stage: V
The differential output voltage is (in Volts):
The differential gain named gain (G
V
terminal of the loudspeaker should be connected to V
Low and high frequency response
In the low frequency region, C
with a -3 dB cut-off frequency. F
In the high frequency region, you can limit the bandwidth by adding a capacitor (C
parallel with R
out2
Single-ended output 1 = V
Single-ended output 2 = V
and V
is in phase with V
out1
feed
- V
out2
. It forms a low-pass filter with a -3 dB cut-off frequency. F
= 2V
in
in
out2
effect), the output voltage of the first stage is (in Volts):
and V
out
= -V
(V)
in
out1
out2
out1
CL
out1
G
starts to have an effect. C
V
v
V
out2
is in Hz.
F
= V
= -V
is phased 180° with V
v
=
out1
(V)
CH
) for more convenience is:
P
V
----------------------------------
F
out
out
–
out
out2
CL
=
V
=
(V)
out1
=
------------------------------------
2πR
(V)
V
=
(
–
–
in
(
------------------------------
V
V
2V
----------------------- -
2πR
feed
in
out1
=
out
)
1
R
Figure 1 on page
R
------------- -
2V
1
in
R
C
L
feed
RMS
C
=
in
feed
in
in
R
------------- -
2
)
out2
2
R
feed
R
------------- -
in
R
feed
in
in
and the negative to V
in
. This means that the positive
forms with R
4.
in
a high-pass filter
CH
is in Hz.
out1
feed
.
TS4990
) in