Philips Semiconductors

TDA8941P

1.5 W mono BTL audio amplifier

Product specification

Rev. 02 — 7 April 2000

4 of 21

9397 750 06864

© Philips Electronics N.V. 2000. All rights reserved.

The input cut-off frequency is:

(1)

(2)

As shown in Equation 1 and 2, large capacitor values for the inputs are not

minimized. This results in a good low frequency response and good switch-on

behaviour.

Remark: To prevent HF oscillations do not leave the inputs open, connect a capacitor

of at least 1.5 nF across the input pins close to the device.

8.2 Power amplifier

The power amplifier is a Bridge Tied Load (BTL) amplifier with an all-NPN output

stage, capable of delivering a peak output current of 2 A.

The BTL principle offers the following advantages:

8.2.1

Output power measurement

The output power as a function of the supply voltage is measured on the output pins

at THD = 10%; see Figure 8. The maximum output power is limited by the maximum

power dissipation in the plastic package.

8.2.2

Headroom

Typical CD music requires at least 12 dB (factor 15.85) dynamic headroom –

compared to the average power output – for transferring the loudest parts without

Average Listening Level (ALL) – music power – without any distortion yields:

The power dissipation can be derived from Figure 11 on page 10 for 0 dB

respectively 12 dB headroom.

f

i cut

off

–

()

1

2

π R

i

C

i

×

()

-----------------------------

=

f

i cut

off

–

()

1

2

π 45 10

3

×

220

×

10

9

–

×

()

-----------------------------------------------------------------

16 Hz

==