Datasheet

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C
BYP
 10  C
i
(8)
DIFFERENTIAL INPUT
SHUTDOWN MODES
USING LOW-ESR CAPACITORS
TPA2000D1
SLOS328F – JUNE 2000 – REVISED MARCH 2004
Increasing the bypass capacitor reduces clicking and popping noise from power on/off and entering and leaving
shutdown. To have minimal pop, C
BYP
should be 10 times larger than C
i
.
The differential input stage of the amplifier cancels any noise that appears on both input lines of the channel. To
use the TPA2000D1 EVM with a differential source, connect the positive lead of the audio source to the INP
input and the negative lead from the audio source to the INN input. To use the TPA2000D1 with a single-ended
source, ac ground the INN input through a capacitor and apply the audio single to the input. In a single-ended
input application, the INN input should be ac-grounded at the audio source instead of at the device input for best
noise performance.
The TPA2000D1 employs a shutdown mode of operation designed to reduce supply current (I
DD
) to the absolute
minimum level during periods of nonuse for battery-power conservation. The SHUTDOWN input terminal should
be held high during normal operation when the amplifier is in use. Pulling SHUTDOWN low causes the outputs to
mute and the amplifier to enter a low-current state, I
DD(SD)
= 1 µA. SHUTDOWN should never be left
unconnected because amplifier operation would be unpredictable.
Low-ESR capacitors are recommended throughout this application section. A real (as opposed to ideal) 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.
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