2
L
P
L
S
OUT
L
R
V
R + 2
R
P
=
for unclipped power
2
R
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ö
æ
ö
´
ç
÷
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÷
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16
TPA3116D2, TPA3118D2, TPA3130D2
SLOS708G – APRIL 2012 – REVISED DECEMBER 2017
Product Folder Links:
Copyright © 2012–2017, Texas Instruments Incorporated
(1)
PLIMIT measurements taken with EVM gain set to 26 dB and input voltage set to 1 V
rms
.
where
•
P
OUT
(10% THD) = 1.25 × P
OUT
(unclipped)
•
R
L
is the load resistance.
•
R
S
is the total series resistance including R
DS(on)
, and output filter resistance.
•
V
P
is the peak amplitude
•
V
P
= 4 × PLIMIT voltage if PLIMIT < 4 × V
P
(2)
Table 3. Power Limit Example
PV
CC
(V)
PLIMIT VOLTAGE (V)
(1)
R to GND
R to GVDD
OUTPUT VOLTAGE (V
rms
)
24 V
GVDD
Open
Short
17.9
24 V
3.3
45 k
Ω
51 k
Ω
12.67
24 V
2.25
24 k
Ω
51 k
Ω
9
12 V
GVDD
Short
Open
10.33
12 V
2.25
24 k
Ω
51 k
Ω
9
12 V
1.5
18 k
Ω
68 k
Ω
6.3
7.3.5 GVDD Supply
The GVDD Supply is used to power the gates of the output full bridge transistors. It can also be used to supply
the PLIMIT and GAIN/SLV voltage dividers. Decouple GVDD with a X5R ceramic 1 µF capacitor to GND. The
GVDD supply is not intended to be used for external supply. It is recommended to limit the current consumption
by using resistor voltage dividers for GAIN/SLV and PLIMIT of 100 k
Ω
or more.
7.3.6 BSPx AND BSNx Capacitors
The full 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 of quality X5R or better, rated for at
least 16 V, must be connected from each output to its corresponding bootstrap input. (See the application circuit
diagram in
.) The bootstrap capacitors connected between the BSxx pins and corresponding output
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.
7.3.7 Differential Inputs
The differential input stage of the amplifier cancels any noise that appears on both input lines of the channel. To
use the TPA31xxD2 family with a differential source, connect the positive lead of the audio source to the RINP or
LINP input and the negative lead from the audio source to the RINN or LINN input. To use the TPA31xxD2 family
with a single-ended source, ac ground the negative input through a capacitor equal in value to the input capacitor
on positive 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. For good
transient performance, the impedance seen at each of the two differential inputs should be the same.
The impedance seen at the inputs should be limited to an RC time constant of 1 ms or less if possible. This is to
allow the input dc blocking capacitors to become completely charged during the 10 ms power-up time. If the input
capacitors are not allowed to completely charge, there will be some additional sensitivity to component matching
which can result in pop if the input components are not well matched.
