AD8622 spice model output current at zero input

Hello,

My test circuit is very simple: non inverter amp, gain 2, 500 ohms resistors .Input is 1uV(for test).I measured Vout ~-1mV .The input bias current was measured to be ~300p, but the output current  was ~1.2uA, so it is the reason to the -1mV output.

Is it a real fact of the component or only a problem of the model? 

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    •  Analog Employees 
    on Nov 13, 2020 5:29 AM

    Hi,

    Can you attach your ltspice circuit here?

    Thanks.

  • Here.I didn't find option to insert a file- so here is the asc file as a text, save it as a file with a some name.

    Version 4
    SHEET 1 1772 680
    WIRE -304 -64 -320 -64
    WIRE -128 -64 -160 -64
    WIRE -320 -32 -320 -64
    WIRE -160 -32 -160 -64
    WIRE -128 192 -192 192
    WIRE -16 192 -48 192
    WIRE -128 320 -128 288
    WIRE -304 336 -336 336
    WIRE -192 336 -192 192
    WIRE -192 336 -224 336
    WIRE -160 336 -192 336
    WIRE -336 352 -336 336
    WIRE -16 352 -16 192
    WIRE -16 352 -96 352
    WIRE 32 352 -16 352
    WIRE -528 368 -592 368
    WIRE -464 368 -528 368
    WIRE -160 368 -384 368
    WIRE -592 400 -592 368
    WIRE -128 416 -128 384
    WIRE -592 560 -592 480
    FLAG -320 48 0
    FLAG -160 48 0
    FLAG -304 -64 VDD
    FLAG -128 -64 VEE
    FLAG -592 560 0
    FLAG -128 288 VDD
    FLAG -128 416 VEE
    FLAG -528 368 VIN
    FLAG -336 352 0
    FLAG 32 352 out
    SYMBOL voltage -320 -48 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    WINDOW 0 -68 46 Left 2
    WINDOW 3 -109 131 Left 2
    SYMATTR InstName V1
    SYMATTR Value PWL(0 0 +10u 6)
    SYMBOL voltage -160 -48 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    WINDOW 0 -70 50 Left 2
    WINDOW 3 -42 129 Left 2
    SYMATTR InstName V2
    SYMATTR Value PWL(0 0 +10u -6)
    SYMBOL res -32 176 R90
    WINDOW 0 0 56 VBottom 2
    WINDOW 3 32 56 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 500
    SYMBOL res -208 320 R90
    WINDOW 0 -38 56 VBottom 2
    WINDOW 3 -37 54 VTop 2
    SYMATTR InstName R2
    SYMATTR Value 500
    SYMBOL voltage -592 384 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V3
    SYMATTR Value 1µV
    SYMBOL Opamps\\AD8624 -128 288 R0
    SYMATTR InstName U1
    SYMBOL res -368 352 R90
    WINDOW 0 0 56 VBottom 2
    WINDOW 3 32 56 VTop 2
    SYMATTR InstName R10
    SYMATTR Value 5k
    TEXT -272 616 Left 2 !.tran 1m startup
    TEXT -264 640 Left 2 !.option noopiter

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  • Here.I didn't find option to insert a file- so here is the asc file as a text, save it as a file with a some name.

    Version 4
    SHEET 1 1772 680
    WIRE -304 -64 -320 -64
    WIRE -128 -64 -160 -64
    WIRE -320 -32 -320 -64
    WIRE -160 -32 -160 -64
    WIRE -128 192 -192 192
    WIRE -16 192 -48 192
    WIRE -128 320 -128 288
    WIRE -304 336 -336 336
    WIRE -192 336 -192 192
    WIRE -192 336 -224 336
    WIRE -160 336 -192 336
    WIRE -336 352 -336 336
    WIRE -16 352 -16 192
    WIRE -16 352 -96 352
    WIRE 32 352 -16 352
    WIRE -528 368 -592 368
    WIRE -464 368 -528 368
    WIRE -160 368 -384 368
    WIRE -592 400 -592 368
    WIRE -128 416 -128 384
    WIRE -592 560 -592 480
    FLAG -320 48 0
    FLAG -160 48 0
    FLAG -304 -64 VDD
    FLAG -128 -64 VEE
    FLAG -592 560 0
    FLAG -128 288 VDD
    FLAG -128 416 VEE
    FLAG -528 368 VIN
    FLAG -336 352 0
    FLAG 32 352 out
    SYMBOL voltage -320 -48 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    WINDOW 0 -68 46 Left 2
    WINDOW 3 -109 131 Left 2
    SYMATTR InstName V1
    SYMATTR Value PWL(0 0 +10u 6)
    SYMBOL voltage -160 -48 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    WINDOW 0 -70 50 Left 2
    WINDOW 3 -42 129 Left 2
    SYMATTR InstName V2
    SYMATTR Value PWL(0 0 +10u -6)
    SYMBOL res -32 176 R90
    WINDOW 0 0 56 VBottom 2
    WINDOW 3 32 56 VTop 2
    SYMATTR InstName R1
    SYMATTR Value 500
    SYMBOL res -208 320 R90
    WINDOW 0 -38 56 VBottom 2
    WINDOW 3 -37 54 VTop 2
    SYMATTR InstName R2
    SYMATTR Value 500
    SYMBOL voltage -592 384 R0
    WINDOW 123 0 0 Left 0
    WINDOW 39 0 0 Left 0
    SYMATTR InstName V3
    SYMATTR Value 1µV
    SYMBOL Opamps\\AD8624 -128 288 R0
    SYMATTR InstName U1
    SYMBOL res -368 352 R90
    WINDOW 0 0 56 VBottom 2
    WINDOW 3 32 56 VTop 2
    SYMATTR InstName R10
    SYMATTR Value 5k
    TEXT -272 616 Left 2 !.tran 1m startup
    TEXT -264 640 Left 2 !.option noopiter

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