Philips Semiconductors

TDA8944AJ

2 x 7 W BTL audio amplifier with DC gain control

Product data

Rev. 01 — 01 March 2002

4 of 20

9397 750 09433

© Koninklijke Philips Electronics N.V. 2002. All rights reserved.

8.

Functional description

The TDA8944AJ is a stereo BTL audio power amplifier capable of delivering 2

× 7W

output power to an 8

Ω load at THD = 10%, using a 12 V power supply and an

external heatsink. The gain of both amplifiers can be adjusted through a DC control

voltage (pin GC). This feature can be used for volume control or a preset gain.

With the three-level MODE input the device can be switched from ‘standby’ to ‘mute’

and to ‘operating’ mode.

The TDA8944AJ outputs are protected by an internal thermal shutdown protection

mechanism and a short-circuit protection.

8.1 Input configuration

The TDA8944AJ inputs can be driven symmetrical (floating) as well as asymmetrical.

In the asymmetrical mode one input pin is connected via a capacitor to the signal

source and the other input is connected to the signal ground. This signal ground

should be as close as possible to the SVR (electrolytic) capacitor ground. Note that

for both pins are necessary.

GC

13

DC gain control

OUT2

−

14

negative loudspeaker terminal 2

GND2

15

ground channel 2

16

supply voltage channel 2

OUT2

+

17

positive loudspeaker terminal 2

Table 3:

Symbol

Pin

Description

Fig 3.

Asymmetrical input configuration.

handbook, halfpage

MGW589

power

ground

signal

ground

signal

source

IN

+

IN

−

SVR

VCC