TPA731

700mW MONO LOW VOLTAGE AUDIO POWER AMPLIFIER

WITH DIFFERENTIAL INPUTS

SLOS315B − JUNE 2000 − REVISED OCTOBER 2002

17

POST OFFICE BOX 655303

APPLICATION INFORMATION

determined in equation 8.

(8)

−3 dB

fc

fc +

1

2

pR

I

C

I

Equation 8 is reconfigured as equation 9.

(9)

C

I +

1

2

pR

I

fc

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

than the source dc level. It is important to confirm the capacitor polarity in the application.

The TPA731 is a high-performance CMOS audio amplifier that requires adequate power supply decoupling to

ensure the output total harmonic distortion (THD) is as low as possible. Power supply decoupling also prevents

oscillations for long lead lengths between the amplifier and the speaker. The optimum decoupling is achieved

by using two capacitors of different types that target different types of noise on the power supply leads. For

higher frequency transients, spikes, or digital hash on the line, a good low equivalent-series-resistance (ESR)

ceramic capacitor, typically 0.1

lower-frequency noise signals, a larger aluminum electrolytic capacitor of 10

µF or greater placed near the audio

power amplifier is recommended.