Datasheet

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10M100k 500M1M 100M10k1k10010
f − Frequency − Hz
Normalized Output Response − dB
−3
−5
−7
−9
−4
−6
−8
−1
0
−2
1
R
L
= 100 Ω
R
L
= 25 Ω
V
CC
= ±15 V
R
F
= 1 kΩ
Gain = 1 V/V
V
I
= 200 mV
R
L
= 50 Ω
R
L
= 200 Ω
10M100k 500M1M 100M10k1k10010
f − Frequency − Hz
Normalized Output Response − dB
V
CC
= ±15 V
R
F
= 1 kΩ
Gain = 2 V/V
V
I
= 200 mV
−3
−5
−7
−9
−4
−6
−8
−1
0
−2
1
R
L
= 100 Ω
R
L
= 25 Ω
R
L
= 200 Ω
R
L
= 50 Ω
10M100k 500M1M 100M10k1k10010
f − Frequency − Hz
−5
−6
−2
−1
Output Amplitude − dB
0
3
1
2
−4
−3
V
CC
= ± 5 V
Gain = 1 V/V
R
L
= 25 Ω
V
I
= 200 mV
R
F
= 1 kΩ
R
F
= 1.5 kΩ
R
F
= 620 Ω
10M100k 500M1M 100M10k1k10010
f − Frequency − Hz
1
0
4
5
Output Amplitude − dB
6
9
7
8
2
3
V
CC
= ± 5 V
Gain = 2 V/V
R
L
= 25 Ω
V
I
= 200 mV
R
F
= 820 Ω
R
F
= 1.2 kΩ
R
F
= 510 Ω
PCB Layout
TPA6120A2
SLOS431 – MARCH 2004
APPLICATION INFORMATION (continued)
Figure 29. Normalized Output Response vs Frequency Figure 30. Normalized Output Response vs Frequency
Figure 31. Output Amplitude vs Frequency Figure 32. Output Amplitude vs Frequency
Proper board layout is crucial to getting the maximum performance out of the TPA6120A2.
A ground plane should be used on the board to provide a low inductive ground connection. Having a ground
plane underneath traces adds capacitance, so care must be taken when laying out the ground plane on the
underside of the board (assuming a 2-layer board). The ground plane is necessary on the bottom for thermal
reasons. However, certain areas of the ground plane should be left unfilled. The area underneath the device
where the PowerPAD is soldered down should remain, but there should be no ground plane underneath any of
the input and output pins. This places capacitance directly on those pins and leads to oscillation problems. The
underside ground plane should remain unfilled until it crosses the device side of the input resistors and the
output series resistor. Thermal reliefs should be avoided if possible because of the inductance they introduce.
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