TPA6030A4

SLOS395B − DECEMBER 2002 − REVISED JANUARY 2005

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load varies from 16 Ω, 32 Ω, 10 kΩ, and 47 kΩ. Table 3 summarizes the frequency response characteristics of each of the

preceding configurations.

Table 3. Load Impedances vs Low Frequency Characteristics in SE Mode

(Ω)

(µF)

LOWEST FREQUENCY

(Hz)

16

220

45

32

220

23

10k

220

0.07

47k

220

0.015

Using Low-ESR Capacitors

Low-ESR capacitors are recommended throughout this applications 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 the 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.

Bridge-Tied Load Versus Single-Ended Mode

Figure 24 shows a Class-AB audio power amplifier (APA) in a bridge-tied-load (BTL) configuration. The TPA6030A4

amplifier consists of two Class-AB differential amplifiers driving both the positive and negative terminals of the load (per

channel). Specifically, differential drive means that as one side amplifier (the positive terminal, for example) is slewing up,

the other side is slewing down, and vice versa. This doubles the voltage swing across the load as opposed to a

the power equation yields 4X the output power from the same supply rail and load impedance as would have been obtained

with a ground referenced load (see equation 9).

V(RMS) +

VO(PP)

22

Power +

V(RMS) 2

RL

Figure 24. Bridge-Tied-Load Configuration

(9)