Datasheet

−100
−90
−80
−70
−60
−50
−40
−30
−20
−10
0
f − Frequency − Hz
Power Supply Rejection Ratio − dB
G026
20 100 1k 10k 20k
V
CC
= 24 V
V
O(ripple)
= 0.2 V
PP
R
L
= 8 Ω (SE)
Gain = 20 dB
−100
−90
−80
−70
−60
−50
−40
−30
−20
−10
0
f − Frequency − Hz
Power Supply Rejection Ratio − dB
G027
20 100 1k 10k 20k
V
CC
= 24 V
V
O(ripple)
= 0.2 V
PP
R
L
= 8 Ω (SE)
Gain = 20 dB
VCC
MUTE
SHUTDOWN
C6
1.0 Fm
R7
C12 0.22 Fm
0.22 Fm
C19
+
1 2
TPA3121D2
PVCCL1
1
SDZ
2
PVCCL2
3
MUTE
4
LIN
5
RIN
6
BYP
7
GND1
8
GND2
9
PVCCR1
10
VCLAMP
11
PVCCR2
12
PVSSR2
13
PVSSR1
14
OUTR
15
BSR
16
GAIN1
17
GAIN0
18
AVCC2
19
AVCC1
20
BSL
21
OUTL
22
PVSSL2
23
PVSSL1
24
THERMAL
25
R6
C13
220 Fm
220 W
R8
C7 0.1 Fm
C8
470 Fm
+
1
2
C14
0.1 Fm
0.22 Fm
C20
4.75kW
4.75kW
+
1 2
C15 0.22 Fm
C2
470 Fm
+
1
2
0.1 Fm
C1
C5
1.0 Fm
C3
1.0 Fm
C4
1.0 Fm
L1
33 Fm
L2
33 Fm
C17
470 Fm
C10
470 Fm
TPA3121D2
SLOS537A –MAY 2008–REVISED AUGUST 2010 www.ti.com
Figure 29. PSRR Without AVCC Filter Figure 30. PSRR With AVCC Filter
Figure 31. Application Schematic with 220-Ω/220-mF AVCC Filter
BSN and BSP Capacitors
The half H-bridge output stages use only NMOS transistors. Therefore, they require bootstrap capacitors for the
high side of each output to turn on correctly. A 220-nF ceramic capacitor, rated for at least 25 V, must be
connected from each output to its corresponding bootstrap input. Specifically, one 220-nF capacitor must be
connected from LOUT to BSL, and one 220-nF capacitor must be connected from ROUT to BSR.
The bootstrap capacitors connected between the BSx pins and their corresponding outputs function as a floating
power supply for the high-side N-channel power MOSFET gate-drive circuitry. During each high-side switching
cycle, the bootstrap capacitors hold the gate-to-source voltage high enough to keep the high-side MOSFETs
turned on.
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