Datasheet
F =
OSC
1
2xROSCxCOSC
TPA3106D1
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SLOS516C –OCTOBER 2007–REVISED AUGUST 2010
ROSC Resistor Selection
The resistor connected to the ROSC terminal controls the class-D output switching frequency using Equation 4:
(4)
COSC is an internal capacitor that is nominally equal to 20 pF. Variation over process and temperature can
result in a ±15% change in this capacitor value.
For example, if ROSC is fixed at 100 kΩ, the frequency from device to device with this fixed resistance could
vary from 217 kHz to 294 kHz with a 15% variation in the internal COSC capacitor. The tolerance of the ROSC
resistor should also be considered to determine the range of expected switching frequencies from device to
device. It is recommended that 1% tolerance resistors be used.
Differential Input
The differential input stage of the amplifier cancels any noise that appears on both input lines of the channel. To
use the TPA3106D1 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 TPA3106D1 with a single-ended source, ac
ground the INP or INN input through a capacitor equal in value to the input capacitor on INN or INP and apply
the audio source to either input. In a single-ended input application, the unused input should be ac grounded at
the audio source instead of at the device input for best noise performance.
SHUTDOWN OPERATION
The TPA3106D1 employs a shutdown mode of operation designed to reduce supply current (I
CC
) to the absolute
minimum level during periods of nonuse for power conservation. The SHUTDOWN input terminal should be held
high (see specification table for trip point) 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. Never leave
SHUTDOWN unconnected, because amplifier operation would be unpredictable.
For the best power-off pop performance, place the amplifier in the shutdown or mute mode prior to removing the
power supply voltage.
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Product Folder Link(s): TPA3106D1