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Thanks everyone for the responses.
Rolf, I do apologize for the incorrect technical term. Yes, its 5 cycles. The input signal doesn't contain any DC level. The signal is the output from the collector of a 2N3904 small-signal amplifier circuit - not sure of the impedance.
MRCecil, could you provide links for the circuit? Would I require feedback (hysteresis)? I tried an LM311 (without hysteresis and single 5V supply) but got a lot of noise at the output and no squarewave. I have attached the implemented circuit. Simulated okay in PSpice Orcad and worked well with input from a signal generator.
Appreciate your suggestions. The input signal is a burst of 5 cycles of ~2Vp-p, 200KHz sinewaves repeated every 5msec.
del
If the signal is not coupled through a blocking capacitor then it likely has a DC level, if it's coming from the collector of a transistor. If it has no DC level than the waveform will have equal excursions above and below 0V.The input signal doesn't contain any DC level. The signal is the output from the collector of a 2N3904 small-signal amplifier circuit - not sure of the impedance.
I don't think a Pspice file will run on LTspice.del
u just have to make ur circuit in PSpice and save it with any name and .asc extension and attach it here....
I don't think a Pspice file will run on LTspice.
I was specifically referring Samad Khan's post, which suggested that simply changing the file extension on a Pspice file would allow it to run on LTspice.Most will but not as a schematic. If you have a running PSpice netlist text file, you CAN run that in LTSpice about 95% of the time.
MRCecil, could you provide links for the circuit? Would I require feedback (hysteresis)? I tried an LM311 (without hysteresis and single 5V supply) but got a lot of noise at the output and no squarewave. I have attached the implemented circuit. Simulated okay in PSpice Orcad and worked well with input from a signal generator.
Appreciate your suggestions. The input signal is a burst of 5 cycles of ~2Vp-p, 200KHz sinewaves repeated every 5msec.
del
I am also partial to LM393, unless you need to sink more than about 4mA. I used LM311 because I thought our OP might have them in stock.Hi Del,
There are plenty of different applications shown in the National datasheet I linked.
Roff has posted a sim for the LM311 that meets your specs. I will attach another simulation using the the same circuit (a tip of the hat to Roff for supplying the .asc file), but using National's spice model for the LM393/LM2903. The only difference I can see may be an 80ns rise and fall time without any overshoot with the LM393.
Good Luck,
Merv
I am also partial to LM393, unless you need to sink more than about 4mA. I used LM311 because I thought our OP might have them in stock.
LM393 worst case sink current is 4mA@700mV. Typically, it drops out of saturation at about 10-20mA.It will sink only 4ma? I thought it was capable of 12 or 15ma...I'll have to look that up so I don't screw up in the future.
Yes, it was good you did use the LM311 to display its capabilities, and a method of hysteresis he questioned. I found the 393 spice model several weeks ago and wanted to see how it performed in LTS.
Cheers,
Merv
LM393 worst case sink current is 4mA@700mV. Typically, it drops out of saturation at about 10-20mA.