The TPA0212 Audio Power Amplifier Evaluation Module
3-6
Details
The line input gain is pin-selectable between 2, 6, 12, and 24 V/V, and the
headphone inputs are fixed at a gain of 1 V/V, as shown in Table 3–1.
Table 3–1. TPA0212 EVM Gain Settings
S2
S3
OUTPUT MODE
GAIN (V/V)
OFF
OFF
BTL
2
OFF
ON
BTL
6
ON
OFF
BTL
12
ON
ON
BTL
24
X
X
SE
1
Note:
ON = Shunt installed, OFF = Open, X = Don’t care
The TPA0212 amplifier IC, like most other amplifiers, exhibits its best distortion
and noise performance at lower gain levels (see the TPA0212 data sheet).
Even so, the TPA0212 at its highest gain setting has significantly less distortion
than most low-cost speakers.
Gain versus total harmonic distortion (THD) should be considered in each
application. Both the module input signal level and the TPA0212 module gain
should be adjusted to obtain the lowest overall distortion level for a particular
overall gain. A quick rule of thumb (everything else being equal): the module
input signal level should be as high as possible without clipping or overloading
the TPA0212 input, and the TPA0212 gain should be kept as low as possible.
3.2.3
Differential Input
The TPA0212 line inputs allow the use of a single-ended or differential audio
source. The differential input stage of the amplifier cancels any noise that
appears on both input lines of a channel. To use the TPA0212 EVM with a
differential source, connect the positive lead of the audio source to the R LINE–
(L LINE–) input and the negative lead from the audio source to the R IN+
(L IN+) input. To use the TPA0212 with a single-ended source, ac-ground the
R IN+ and L IN+ inputs and apply the audio signal to the R LINE– and L LINE–
inputs. Line and headphone inputs share common positive inputs. If using
separate line and headphone inputs, R IN and L IN should be ac-grounded.
If using differential inputs, line and headphone inputs must be the same. In a
single-ended input application, the R IN+ and L IN+ inputs should be ac
grounded at the audio source instead of at the device inputs for best noise
performance.
Summary of Contents for TPA0212
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