Philips TDA8943SF manual Functional description, Pin description, Power amplifier, Mode selection

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Philips Semiconductors

 

TDA8943SF

 

 

 

7 W mono BTL audio amplifier

7.2 Pin description

 

 

Table 4:

Pin description

 

 

 

 

 

 

Symbol

Pin

Description

 

OUT

1

negative loudspeaker terminal

 

 

 

 

 

VCC

2

supply voltage

 

OUT+

3

positive loudspeaker terminal

 

 

 

 

 

IN+

4

positive input

 

 

 

 

 

IN

5

negative input

 

 

 

 

 

SVR

6

half supply voltage decoupling (ripple rejection)

 

 

 

 

 

MODE

7

mode selection input (standby, mute, operating)

 

 

 

 

 

GND

8

ground

 

 

 

 

 

n.c.

9

not connected

 

 

 

 

8. Functional description

The TDA8943SF is a mono BTL audio power amplifier capable of delivering 7 W output power to an 8 Ω load at THD = 10%, using a 12 V power supply and an external heatsink. The voltage gain is fixed at 32 dB.

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

The TDA8943SF outputs are protected by an internal thermal shutdown protection mechanism and a short-circuit protection.

8.1 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 1.5 A.

The BTL principle offers the following advantages:

Lower peak value of the supply current

The ripple frequency on the supply voltage is twice the signal frequency

No expensive DC-blocking capacitor

Good low frequency performance.

8.2Mode selection

The TDA8943SF has three functional modes, which can be selected by applying the proper DC voltage to pin MODE.

Standby — In this mode the current consumption is very low and the outputs are

floating. The device is in standby mode when VMODE > (VCC 0.5 V), or when the MODE pin is left floating.

Mute — In this mode the amplifier is DC-biased but not operational (no audio output). This allows the input coupling capacitors to be charged to avoid pop-noise. The device is in mute mode when 2.5 V < VMODE < (VCC 1.5 V).

9397 750 04877

© Philips Electronics N.V. 1999. All rights reserved.

Preliminary specification

14 April 1999

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