TDA7492E Datasheet, PDF (12/24 Pages) STMicroelectronics – 79 W + 79 W dual BTL class-D audio amplifier

Application information
TDA7492E
The thresholds in MUTE mode are reduced to about 1/2 and two typical thresholds are as
follows.
Table 10: Overcurrent protection (mute mode)
I (Shutdown)
High side (A)
6.2
Low side (A)
5.9
4.3.2
4.3.3
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 TDA7492E automatically recovers when the temperature become lower than
the threshold.
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:
(𝑅𝑅𝑅𝑅𝑅𝑅//400𝑘𝑘)
𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉 = 𝑉𝑉_{𝐷𝐷𝐷𝐷} �_{(𝑅𝑅𝑅𝑅𝑅𝑅//400𝑘𝑘 + 𝑅𝑅𝑅𝑅𝑅𝑅)}�
Figure 4: Recommended power limit pin connections
VDDS
Rup
PLIMIT
Rdn
Power
Limiter
12/24
It is recommended that external resistors are less than 40 kΩ if a voltage divider is used as
shown in Figure 4: "Recommended power limit pin connections". The relationship of the
maximum duty cycle (Dmax) and the voltage at PLIMIT is:
𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷
=
�8.8
×
í µí±‰í µ_𝑉_{í±í µí±í µí±í µí±}
−
𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉
2 × í µí±‰í µ_𝑉_{í±í µí±í µí±í µí±} × 𝑅𝑅𝑅𝑅
𝑅𝑅𝑙𝑙𝑙𝑙 × 2 × 𝑅𝑅𝑅𝑅
2
+
1�
Where VCC is the power supply voltage, VPLIMIT is the voltage applied at the PLIMIT pin, Rs
is the series resistance including Rdson of power transistor, output filter resistance and
bonding wire resistance. Rload is the load resistance.
DocID027638 Rev 1