Table 9. Overcurrent protection (mute mode)

I (shutdown)

High-side (A)

6.2

Low-side (A)

5.9

4.3.2

Thermal protection

When internal die temperature exceeds 140 °C, the device enters into Mute by pulling the MUTE pin low first.

When internal die temperature exceeds 150 °C, the device directly shuts down the power stage. The TDA7492PE

automatically recovers when the temperature become lower than the threshold.

4.3.3

Power limit

A built-in power limit is used to limit the output voltage level below the supply rail by limiting the duty cycle. The

limit level is set through the voltage at PLIMIT (pin 30). The pin voltage is set by the following equation:

 VPLIMIT=VDD Rdn//400k

Rdn//400k +Rup 

(1)

Figure 4. Recommended power limit pin connections

VDDS

Power

Limiter

Rup

Rdn

PLIMIT

It is recommended that external resistors are less than 40 kΩ if a voltage divider is used as shown in

Figure 5. Recommended power limit pin connections. The relationship of the maximum duty cycle (Dmax) and the

voltage at PLIMIT is:

Dmax= 8.8 × 

VPLIMIT

Vcc−  2 ×Vcc×Rs

Rload ×2 ×Rs+1

2

(2)

Where VCC is the power supply voltage, VPLIMIT is the voltage applied at the PLIMIT pin, Rs is the series

resistance including Rdson of the power transistor, output filter resistance and bonding wire resistance. Rload is

the load resistance.

An example of maximum effective control voltage at PLIMIT vs. power supply and load resistance is shown in

Table 10. Max. effective voltage of PLIMIT pin vs. power supply and load.

Table 10. Max. effective voltage of PLIMIT pin vs. power supply and load

Rload

Power supply

7 V

13 V

24 V

4 Ω

0.71 V

1.32 V

2.44 V

6 Ω

0.74 V

1.37 V

2.53 V

8 Ω

0.75 V

1.39 V

2.57 V

TDA7492PE

Smart protections

DS10652 - Rev 3

page 9/19