Datasheet

TS4871
23/28
which gives 16Hz.
In Higher frequency we want 20kHz (-3dB cut off
frequency). The Gain Bandwidth Product of the
TS4871 is 2MHz typical and doesn’t change when
the amplifier delivers power into the load.
The first amplifier has a gain of:
and the theoretical value of the -3dB cut-off higher
frequency is 2MHz/3 = 660kHz.
We can keep this value or limit the bandwidth by
adding a capacitor Cfeed, in parallel on Rfeed.
Then:
So, we could use for Cfeed a 220pF capacitor
value that gives 24kHz.
Now, we can calculate the value of Cb with the
formula τb = 50kΩxCb >> τin = (Rin+Rfeed)xCin
which permits to reduce the pop and click effects.
Then Cb >> 0.8µF.
We can choose for Cb a normalized value of 2.2µF
that gives good results in THD+N and PSRR.
In the following tables, you could find three
another examples with values required for the
demoboard.
Remark : components with (*) marking are
optional.
Application n°1 : 20Hz to 20kHz bandwidth and
6dB gain BTL power amplifier.
Components :
Application n°2 : 20Hz to 20kHz bandwidth and
20dB gain BTL power amplifier.
Components :
C
IN =
1
2π
RinFCL
------------------------------ = 795nF
Rfeed
Rin
----------------- = 3
C
FEED =
1
2π R
FEEDFCH
--------------------------------------- = 265pF
Designator Part Type
R1 22k / 0.125W
R4 22k / 0.125W
R6 Short Cicuit
R7 330k / 0.125W
R8* (Vcc-Vf_led)/If_led
C5 470nF
C6 100µF
C7 100nF
C9 Short Circuit
C10 Short Circuit
C12 1µF
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
S8
3 pts connector 2.54mm
pitch
P1 PCB Phono Jack
D1* Led 3mm
U1 TS4871ID or TS4871IS
Designator Part Type
R1 110k / 0.125W
R4 22k / 0.125W
R6 Short Cicuit
R7 330k / 0.125W
R8* (Vcc-Vf_led)/If_led
C5 470nF
C6 100µF
C7 100nF