Datasheet

_
+
IN−
IN+
PWM H−
Bridge
V
O
−
V
O
+
Internal
Oscillator
C
S
ToBattery
V
DD
GND
Bias
Circuitry
Differential
Input
TPA2011D1
Filter-FreeClassD
EN
C
I
C
I
R
I
C
I
R
I
_
+
IN−
IN+
PWM H−
Bridge
V
O+
V
O−
Internal
Oscillator
C
S
ToBattery
V
DD
GND
Bias
Circuitry
Single-ended
Input
TPA2011D1
Filter-FreeClassD
EN
C
I
C
I
R
I
R
I
Gain 1 +
V
O
V
I1
+
2 x 150 kW
R
I1
ǒ
V
V
Ǔ
Gain 2 +
V
O
V
I2
+
2 x 150 kW
R
I2
ǒ
V
V
Ǔ
TPA2011D1
www.ti.com SLOS626A –DECEMBER 2009–REVISED MAY 2010
Figure 29. TPA2011D1 Application Schematic With Differential Input and Input Capacitors
Figure 30. TPA2011D1 Application Schematic With Single-Ended Input
SUMMING INPUT SIGNALS WITH THE TPA2011D1
Most wireless phones or PDAs need to sum signals at the audio power amplifier or just have two signal sources
that need separate gain. The TPA2011D1 makes it easy to sum signals or use separate signal sources with
different gains. Many phones now use the same speaker for the earpiece and ringer, where the wireless phone
would require a much lower gain for the phone earpiece than for the ringer. PDAs and phones that have stereo
headphones require summing of the right and left channels to output the stereo signal to the mono speaker.
Summing Two Differential Input Signals
Two extra resistors are needed for summing differential signals (a total of 5 components). The gain for each input
source can be set independently (see Equation 4 and Equation 5, and Figure 31).
(4)
(5)
If summing left and right inputs with a gain of 1 V/V, use R
I1
= R
I2
= 300 kΩ.
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Product Folder Link(s) :TPA2011D1