Hi everyone,
I have a problem simulating a AC constant current source according to a simple circuit in TINA-TI. Well, I want to know the frequency response of the current source in the frequency range from 1Hz to 1MHz, loaded with an inductive impedance. When I simulate the circuit with AC Transfer Simulate I get the frequency response curves as in the figure below. According to the datasheet for the LM7171 operational amplifier, the output swing is approx. 11.8V for a load RL = 100 Ohm. However, after performing the simulation of the circuit below for an inductive load at higher frequencies (i.e. 200kHz), I get a voltage at the output of the LM7171 amplifier significantly exceeding the its output swing. In a practical case, the output voltage should not increase with increasing frequency, and the output current should gradually decrease. What is the problem of incorrectly executing this simulation? What am I doing wrong?
Kind regards,
Teodor Serwicki
Kielce University of Technology
Faculty of Electrical Engineering, Automatics and Computer Science
Department of Electrical Engineering and Measurement Systems
e2e.ti.com/.../3426.Ultra-High-Speed-Current-Source-_2D00_-100mA.TSC