TS486IS View Datasheet(PDF) - STMicroelectronics
Part Name
Description
Manufacturer
TS486IS Datasheet PDF : 31 Pages
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TS486-TS487
and for various values of the input resistor RIN .
1000
100
Rin = 10kΩ
Rin = 1kΩ
10
Rin = 100kΩ
Rin = 20kΩ and
fixed gain versions
1
0.01
0.1
1
10
Cin (µF)
The input resistance of the fixed gain version is
typically 20kΩ.
The following curve shows the limits of the roll off
frequency depending on the min. and max. values
of Rin:
Ω
Ω
Ω
LOW FREQUENCY ROLL OFF WITH OUTPUT
CAPACITORS
The DC voltage on the outputs of the TS486/487
is blocked by the output capacitors COUT1 and
COUT2 . Each output capacitor COUT in series with
the resistance of the load RL is equivalent to a first
order high pass filter.
Assuming that Fmin is the lowest frequency to be
amplified (with a 3dB attenuation), the minimum
value of COUT is:
COUT > 1 / (2*π*Fmin*RL)
The following curve gives directly the low roll-off
28/31
frequency versus the output capacitor COUT in µF
and for the two typical 16Ω and 32Ω impedances:
1000
100
RL = 32Ω
10
RL = 16Ω
1
10
100
1000
10000
C ( F)
OUT
DECOUPLING CAPACITOR CB
The internal bias voltage at Vcc/2 is decoupled
with the external capacitor CB.
The TS486 and TS487 have a specified Power
Supply Rejection Ratio parameter with CB = 1µF.
A higher value of CB improves the PSRR, for
example, a 4.7µF improves the PSRR by 15dB at
200Hz (please, refer to fig. 76 "PSRR vs Bypass
Capacitor").
POP PRECAUTIONS
Generally headphones are connected using a
connector as a jack. To prevent a pop in the
headphones when plugged in the jack, a resistor
should be connected in parallel with each
headphone output. This allows the capacitors
Cout to be charged even when no headphone is
plugged.
A resistor of 1 kΩ is high enough to be a negligible
load, and low enough to charge the capacitors
Cout in less than one second.
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