LT Spice opamp a liittle weird

John Larkin · 2017-05-02T01:12:28+00:00

I was wondering about the power dissipation of an opamp, driving a sine wave into a mainly inductive load. See below. The first few cycles current limit or something. I'm using UniversalOpamp2 with current limit 2 amps and rail=0. This opamp isn't documented in the HELP, or much anywhere else. Peak current is under 700 mA, so why is it clipping? Higher supply voltage helps. Version 4 SHEET 1 880 680 WIRE 304 -64 224 -64 WIRE 224 -32 224 -64 WIRE 304 0 304 -64 WIRE 288 64 144 64 WIRE 224 96 224 48 WIRE 144 112 144 64 WIRE 192 112 144 112 WIRE 288 128 288 64 WIRE 288 128 256 128 WIRE 352 128 288 128 WIRE 384 128 352 128 WIRE 512 128 464 128 WIRE 544 128 512 128 WIRE 80 144 48 144 WIRE 192 144 80 144 WIRE 544 176 544 128 WIRE 48 208 48 144 WIRE 224 208 224 160 WIRE 48 320 48 288 WIRE 224 320 224 288 WIRE 544 320 544 256 FLAG 224 320 0 FLAG 544 320 0 FLAG 304 0 0 FLAG 48 320 0 FLAG 80 144 GEN FLAG 352 128 AMP FLAG 512 128 IND SYMBOL res 368 144 R270 WINDOW 0 99 55 VTop 2 WINDOW 3 88 54 VBottom 2 SYMATTR InstName R1 SYMATTR Value 1 SYMBOL Opamps\UniversalOpamp2 224 128 R0 WINDOW 0 37 43 Left 2 SYMATTR InstName U1 SYMATTR SpiceLine ilimit=2 rail=0 Vos=0 phimargin=45 SYMBOL voltage 224 304 R180 WINDOW 0 43 71 Left 2 WINDOW 3 44 38 Left 2 SYMATTR InstName V1 SYMATTR Value 12 SYMBOL voltage 224 64 R180 WINDOW 0 57 77 Left 2 WINDOW 3 57 42 Left 2 SYMATTR InstName V2 SYMATTR Value 12 SYMBOL voltage 48 192 R0 WINDOW 0 -79 47 Left 2 WINDOW 3 -199 89 Left 2 WINDOW 123 0 0 Left 2 WINDOW 39 0 0 Left 2 SYMATTR InstName V3 SYMATTR Value SINE(0 10 400) SYMBOL ind 528 160 R0 WINDOW 0 72 41 Left 2 WINDOW 3 62 76 Left 2 SYMATTR InstName L1 SYMATTR Value 10m TEXT -127 102 Left 2 !.tran 25m TEXT -160 0 Left 2 ;Amp PdissTest TEXT -152 48 Left 2 ;JL May 1, 2017 -- John Larkin Highland Technology, Inc picosecond timing precision measurement jlarkin att highlandtechnology dott com

May 02, 2017 21 Replies

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Jim Thompson 9 years ago

[snip]

Try "Op-Amp-Config.zip" on the Device Models & Subcircuits Page of my website... _everything_ specifiable _except_ current limit.

More highly refined models available for a fee >:-} ...Jim Thompson

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Steve Wilson 9 years ago

even

Here's a non-Yahoo link to Helmut's modified UniversalOpamps2:

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I haven't tested it yet but I trust Helmut's work.

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