Connect with us

Temperature compensation in LTSpice?

Discussion in 'Electronic Basics' started by Bill Bowden, Feb 15, 2013.

Scroll to continue with content
  1. Bill Bowden

    Bill Bowden Guest

    Is it possible to simulate circuit performance using LTSpice under
    different temperature conditions? Say you have a single NPN transistor
    with grounded emitter and a collector load and a resistor from base to
    collector so the collector voltage is about half the supply voltage. I
    understand the result would depend on the HFE of the transistor,
    temperature, and maybe not very stable. Just wondering if LTSpice can
    provide any interesting information for some particular transistor. DC
    voltage change verses temperature.

    -Bill
     
  2. Bill Bowden

    Bill Bowden Guest

    Yes, that works fine to plot the e/b and b/c voltage temp conditions.
    I tried adding a spice directive of (.step temp 0 50 5) to my
    transistor stage and I get 10 lines displayed (5 to 6 volts) which I
    presume correspond to the 10 temperature steps. But the display
    doesn't indicate what voltage occurs at what temperature. How to fix
    that?

    -Bill

    Version 4
    SHEET 1 880 680
    WIRE 144 16 16 16
    WIRE -128 144 -192 144
    WIRE 16 144 16 96
    WIRE 16 144 -64 144
    WIRE 16 208 16 144
    WIRE -192 256 -192 144
    WIRE -160 256 -192 256
    WIRE -48 256 -80 256
    WIRE 16 320 16 304
    FLAG 144 96 0
    FLAG 16 320 0
    SYMBOL voltage 144 0 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V1
    SYMATTR Value 12
    SYMBOL npn -48 208 R0
    SYMATTR InstName Q2
    SYMATTR Value 2N3904
    SYMBOL res 0 0 R0
    SYMATTR InstName R3
    SYMATTR Value 22k
    SYMBOL res -64 240 R90
    WINDOW 0 0 56 VBottom 0
    WINDOW 3 32 56 VTop 0
    SYMATTR InstName R4
    SYMATTR Value 5000k
    SYMBOL diode -64 128 R90
    WINDOW 0 0 32 VBottom 0
    WINDOW 3 36 -4 VTop 0
    SYMATTR InstName D2
    SYMATTR Value 1N4148
    TEXT -40 392 Left 0 !.step temp 0 50 5
    TEXT -200 392 Left 0 !.tran .1s
     
  3. Fred Abse

    Fred Abse Guest

    Right click on the plot screen. Click on "Select Steps"
     
Ask a Question
Want to reply to this thread or ask your own question?
You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Electronics Point Logo
Continue to site
Quote of the day

-