LM139A: Power Dissipation Calculations

rahul ravi

Part Number: LM139A

How does one calculate the power dissipation for this part?
What is the rated power dissipation for this part?

I am looking for an electrical way to estimate the power dissipation for ex.: Pd=Vcc*ICC. Is there an electrical way to do this? I can then use the calculated power dissipation to then estimate the actual temperature rise and a junction temperature. Also what is the RATED power dissipation for this device?

over 3 years ago

0 Clemens Ladisch over 3 years ago

Guru 273010 points

The worst-case supply current is specified as 2 mA. This current flows into the V_CC pin and out of the GND pin, so V_CC × I_CC applies.

The input bias current is too small to matter.

If the output is low and connected to a large load, the power dissipation in the output transistor is V_O × I_O. Typical values for those are shown in figure 3.

The allowed power dissipation is (T_J − T_A) / R_θJA, which depends on the actual ambient temperature.

0 Chuck Sins over 3 years ago in reply to Clemens Ladisch

TI__Mastermind 24310 points

Thanks Clemens for your support.

Chuck

Amplifiers

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LM139A: Power Dissipation Calculations