I have a problem witht the AC analysis of a circuit. The circuit is a voltage driven constant current driver: It is intended to drive a constant current into L1 (R1 being the series resistance of the inductor). R2 is the resistor to sense the current passing through the coil. U2, U3 and associated resistors are just there to rescale the voltage so that a variation of 1V on V3 will lead to a variation of 1A in L1.
The AC analysis give the following response: We can see that at 1kHz, the gain is still more or less the same as at 10 or 100Hz: -20dB represent 100mV across R2 wich is then 1A. When I do the transient response with V3 at 1V/10Hz I see the 1A passing through R2, but when I do it at 1kHz I only see 500mA through R2.
That is actually normal because at 1kHz, the coil reactance is R=wL=31 Ohms. The power supply being +/-15V the current passing through the coil and through R2 cannot be higher than 500mA (15V/~30 Ohms) meaning at 1kHz the amplitude is actually divided by 2 so the gain should not be the same at 10Hz and 1kHz.
This information is not visible on the AC analysis so my question is: Is LTSPICE ignoring any power supply limitation of an OPAMP when it does AC analysis?