TS4995 datasheet(19/26 Pages) STMICROELECTRONICS

19 / 26 page

TS4995

Application information

19/26

Therefore, the power dissipated by each amplifier is:

Pdiss = Psupply - Pout (W)

and the maximum value is obtained when:

and its value is:

Equation 3

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 4

The maximum theoretical value is reached when Vpeak = VCC, so:

The maximum die temperature allowable for the TS4995 is 125° C. However, in case of

overheating, a thermal shutdown set to 150° C, puts the TS4995 in standby until the

temperature of the die is reduced by about 5° C.

To calculate the maximum ambient temperature Tamb allowable, you need to know:

●

The power supply voltage, VCC

●

The load resistor value, RL

●

The package type, Rthja

Example: VCC=5 V, RL=8 Ω, Rthja-flipchip= 100° C/W (100 mm

2 copper heatsink).

Using the power dissipation formula given above in Equation 3, this gives a result of:

Pdissmax = 633mW

Tamb is calculated as follows:

Equation 5

Therefore, the maximum allowable value for Tamb is:

Tamb = 125-100x0.633=61.7° C

diss

22V

π R

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

out Pout

–

∂Pdiss

∂P

out

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

)

(

Vcc

max

Pdiss

η=

out

supply

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

πV

peak

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

η= π

----- = 78.5%

amb

125

° CR

thja

dissmax

–

TS4995 Datasheet(PDF) 19 Page - STMicroelectronics

TS4995 Datasheet(HTML) 19 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26

Datasheet Download

Link URL