0

5

10

15

20

25

30

6

8

10

12

14

16

18

20

22

24

26

G016

THD = 10%

THD = 1%

Gain = 20 dB

+ 66 µH

0

5

10

15

20

25

6

8

10

12

14

16

18

G017

THD = 10%

THD = 1%

Gain = 20 dB

+ 33 µH

TPA3110D2

SLOS528E – JULY 2009 – REVISED NOVEMBER 2015

www.ti.com

leakage current creates a dc offset voltage at the input to the amplifier that reduces useful headroom, especially

in high gain applications. For this reason, a low-leakage tantalum or ceramic capacitor is the best choice. When

polarized capacitors are used, the positive side of the capacitor should face the amplifier input in most

applications as the dc level there is held at 3 V, which is likely higher than the source dc level. Note that it is

important to confirm the capacitor polarity in the application. Additionally, lead-free solder can create dc offset

voltages and it is important to ensure that boards are cleaned properly.

10.2.1.2.3

BSN and BSP 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 0.22

μF ceramic capacitor, rated for at least 25 V, must be

connected from each output to its corresponding bootstrap input. Specifically, one 0.22

μF capacitor must be

connected from OUTPx to BSPx, and one 0.22

μF capacitor must be connected from OUTNx to BSNx. (See the

application circuit diagram in Figure 41.)

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.

10.2.1.2.4

Using Low-ESR Capacitors

Low-ESR capacitors are recommended throughout this application section. A real (as opposed to ideal) capacitor

can be modeled simply as a resistor in series with an ideal capacitor. The voltage drop across this resistor

minimizes the beneficial effects of the capacitor in the circuit. The lower the equivalent value of this resistance,

the more the real capacitor behaves like an ideal capacitor.

10.2.1.3 Application Curves

Note: Dashed Lines represent thermally limited regions.

Note: Dashed Lines represent thermally limited regions.

Figure 43. Output Power vs Supply Voltage (BTL)

Figure 44. Output Power vs Supply Voltage (BTL)

22

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