Regarding LM2941 voltage regulator

[kiranhatti]

Hi everyone,

I need one clarification please help me out.

I am using LM2941 regulator in my project. Vin is 24V and Vout is 5V. The application is just contains 4 seven segment LED display and corresponding driver IC's. There are 18F252 microcontroller and Max485 IC.

I am afraid that whether the regulator gets heated up?

 

[esp1]

hi,
The datasheet graphs show approx 2Watt dissipation at ta= 40Cdeg [no heat sink]
So roughly that is 24Vin -5Vout =19V drop across the regulator , which is 2W/19V = ~ 100mA.

With a 10C/W heat sink at ta= 40C that will supply ~400mA.

E

 

[Audioguru]

You forgot to tell us which package the regulator has. A big package with a metal tab for plenty of dissipation (heating) when bolted onto a heatsink, or a tiny package that is not allowed to have much heating.

 

[kiranhatti]

Sorry... The package is TO220 and the regulator will fixed to the heatsink.

Can you please confirm that the heating up of regulator wont create any problem with circuit?

 

[FvM]

Can you please confirm that the heating up of regulator wont create any problem with circuit?

Impossible witout knowing the circuit current consumption (particularly display current which is set by your design) and the heatsink C/W number.

esp1 explained the calculation scheme, put in the actual numbers and calculate yourself.