Datasheet

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1

C
(BYP)
 230 kΩ


1

C
I
R
I


1
R
L
C
(C)
(8)
USING LOW-ESR CAPACITORS
5-V VERSUS 3.3-V OPERATION
TPA6111A2
SLOS313B – DECEMBER 2000 – REVISED JUNE 2004
The output coupling capacitor required in single-supply SE mode also places additional constraints on the
selection of other components in the amplifier circuit. With the rules described earlier still valid, add the following
relationship:
Low-ESR capacitors are recommended throughout this application. A real capacitor can be modeled simply as a
resistor in series with an ideal capacitor. The voltage drop across this resistor minimizes the beneficial effects of
the capacitor in the circuit. The lower the equivalent value of this resistance, the more the real capacitor behaves
like an ideal capacitor.
The TPA6111A2 was designed for operation over a supply range of 2.5 V to 5.5 V. This data sheet provides full
specifications for 5-V and 3.3-V operation, since these are considered to be the two most common standard
voltages. There are no special considerations for 3.3-V versus 5-V operation as far as supply bypassing, gain
setting, or stability. The most important consideration is that of output power. Each amplifier in the TPA6111A2
can produce a maximum voltage swing of V
DD
– 1 V. This means, for 3.3-V operation, clipping starts to occur
when V
O(PP)
= 2.3 V as opposed when V
O(PP)
= 4 V while operating at 5 V. The reduced voltage swing
subsequently reduces maximum output power into the load before distortion begins to become significant.
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