Application information

TS4997

24/34

and the maximum value is obtained when:

and its value is:

Equation 5

Note:

This maximum value is only dependent on the power supply voltage and load values.

The efficiency is the ratio between the output power and the power supply:

Equation 6

The TS4997 is stereo amplifier so it has two power amplifiers. Each amplifier produces heat

due to its power dissipation. Therefore, the maximum die temperature is the sum of each

amplifier’s maximum power dissipation. It is calculated as follows:

●

●

●

The maximum die temperature allowable for the TS4997 is 150°C. In case of overheating, a

thermal shutdown protection set to 150°C, puts the TS4997 in standby until the temperature

of the die is reduced by about 5°C.

●

●

●

Using the power dissipation formula given in Equation 5, the maximum dissipated power per

channel is:

And the power dissipated by both channels is:

∂Pdiss

∂P

out

--------------------- = 0

)

W

(

R

Vcc

2

max

Pdiss

L

2

2

π

=

η=

P

out

P

supply

------------------- =

πV

peak

4Vcc

--------------------

4

----- = 78.5%

TotalP

P

diss1

×

42V

CC

π R

L

---------------------- P

()

–

=