Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

temperature descranpancy between the junction and ambient

Status
Not open for further replies.
C

chang830

Full Member level 5
Joined
Feb 11, 2006
Messages
267
Helped
14
Reputation
28
Reaction score
3
Trophy points
1,298
Activity points
3,424
Hi,
I always see many IC product assert they meet spec on ambient temperatutre from -40'C to 85'C. Then what junction temperature we should use in designing/simulating the cicruit ?In normal, what is the descranpancy between the junction and the ambient temperature?

Thanks
 

Re: temperature descranpancy between the junction and ambien

One cause of elevated junction temperature is self heating.
Any dissipation in the part results in some increase in junction temperature over ambient.
For small signal parts, there may be a high thermal impedance to the surroundings.
If this is true, tiny dissipations can make a measureable temperature rise.

You can choose from these approaches for simulation temperatures, or pick another:
1) Choose a standard temperature, such as 25 C.
2) Calculate dissipation, determine thermal impedance and then calculate temperature rise.
3) Measure a junction voltage on the divice in a real circuit and calculate the temperature from the diode equation.
4) Guess
 

    C

    chang830

    Points: 2
    Helpful Answer Positive Rating
Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top