Philips Semiconductors

TDA8943SF

6 W mono Bridge Tied Load (BTL) audio amplifier

Product specification

Rev. 02 — 7 April 2000

6 of 20

9397 750 06865

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

8.4 Supply Voltage Ripple Rejection (SVRR)

The SVRR is measured with an electrolytic capacitor of 10

µF on pin SVR at a

bandwidth of 10 Hz to 80 kHz. Figure 12 on page 10 illustrates the SVRR as function

of the frequency. A larger capacitor value on the SVR pin improves the ripple rejection

behaviour at the lower frequencies.

8.5 Built-in protection circuits

The TDA8943SF contains two types of protection circuits, i.e. short-circuit and

thermal shutdown.

8.5.1

Short-circuit protection

Short-circuit to ground or supply line — This is detected by a so-called ‘missing

current’ detection circuit which measures the current in the positive supply line and

the current in the ground line. A difference between both currents larger than 0.4 A,

switches the power stage to standby mode (high impedance).

Short-circuit across the load — This is detected by an absolute-current

measurement. An absolute-current larger than 2 A, switches the power stage to

standby mode (high impedance).

8.5.2

Thermal shutdown protection

The junction temperature is measured by a temperature sensor; at a junction

temperature of approximately 150

°C this detection circuit switches the power stage

to standby mode (high impedance).

9.

Limiting values

Table 5:

Limiting values

In accordance with the Absolute Maximum Rating System (IEC 60134).

Symbol

Parameter

Conditions

Min

Max

Unit

supply voltage

no signal

−0.3

+25

V

operating

−0.3

+18

V

input voltage

−0.3

repetitive peak output current

-

2

A

storage temperature

non-operating

−55

+150

°C

operating ambient

temperature

−40

+85

°C

total power dissipation

-

7

W

supply voltage to guarantee

short-circuit protection

-18

V