TS4990 View Datasheet(PDF) - STMicroelectronics
Part Name
Description
MFG CO.
'TS4990' PDF : 33 Pages View PDF
TS4990
Figure 64. Differential input amplifier configuration
R2
Vcc
Neg. Input
Pos. Input
Cin R1
Cin R1
Vin-
-
Vin+
+
Application information
Cs
Vout 1
Speaker
8 Ohms
R2
Standby
Control
Cb
Bypass
Standby
Bias
-
AV = -1
+
Vout 2
TS4990
Note:
The input capacitor Cin can be calculated by the following formula using the -3 dB lower
frequency required. (FL is the lower frequency required).
Cin ≈
---------1-----------
2πR1FL
(F)
This formula is true only if:
FCB = -2---π----(--R-----1----+1-----R----2---)---C----B-- (Hz)
is 5 times lower than FL.
Example bill of materials
The bill of materials in Table 7 is for the example of a differential amplifier with a gain of 2
and a -3 dB lower cut-off frequency of about 80 Hz.
Table 7. Bill of materials for differential input amplifier application
Pin name
Functional description
R1
R2
Cin
Cb=Cs
U1
20k / 1%
20k / 1%
100nF
1µF
TS4990
23/32
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