Thanks for the response. I had used LM339 to generate 100kHz square wave but having issues with using it to generate triangular and sine wave.Not by itself, no. But you can get a sawtooth wave and a square wave with simple op amp circuits. Sine waves require a more complex circuit.
100kHz please.What is the maximum frequency you need?
Okay. Please which of the op-amps for 100kHz?LM339 is a comparator, an op amp would be a better choice.
Yes.can I use LM339 to generate a triangular and sine waveforms?
Thanks. Good to know. I will send my circuit please so you help me check what I have done wrong.Yes.
Did you substitute comparators for both opamps? Did you add pull-up resistors to the comparator output(s)?The op-amp in the schematic is used for design in multisim but I used LM339.
Yes I did substitute comparators for both opamps. I did not add a pull up resistor to the output of the integrator. I did not get an output. Attached is the input to the integrator.Did you substitute comparators for both opamps? Did you add pull-up resistors to the comparator output(s)?
Post waveforms of the input/output of the integrator.
Actually, most el-cheapo function generators start with a square wave, and then use subsequent integration to obtain triangle and sine waves. The 339 is fine for generating the first square wave.Not by itself, no. But you can get a sawtooth wave and a square wave with simple op amp circuits. Sine waves require a more complex circuit.
Not using a pull up is why you didn't get an output. the 339/393 can only sink current not source it, there for they need a pullup resistor.Yes I did substitute comparators for both opamps. I did not add a pull up resistor to the output of the integrator. I did not get an output. Attached is the input to the integrator.
Thanks for the responses. I will add a pullup resistor and give you a feedback on the waveform.Not using a pull up is why you didn't get an output. the 339/393 can only sink current not source it, there for they need a pullup resistor.
Please can you shade more light on what you are saying.Actually, most el-cheapo function generators start with a square wave, and then use subsequent integration to obtain triangle and sine waves. The 339 is fine for generating the first square wave.
sounds like you know where your problem is - the said comparator has OC output.I did not add a pull up resistor to the output of the integrator.
Also, while a 339/393 is based on an opamp, its internal circuit is modified to be a comparator. You would be better off using a real opamp.Thanks for the responses. I will add a pullup resistor and give you a feedback on the waveform.
Integrating a square wave will give a triangle wave, integrating a triangle wave will give a sine wave.Please can you shade more light on what you are saying.
Well, an approximation to one.integrating a triangle wave will give a sine wave.
Yes. The two resistors are connected to the output of the first opamp. R6 is a pull-up resistor to sink the current. I still do not get an output that is triangular wave form. I used a breadboard to connect but cannot get anything.Integrating a square wave will give a triangle wave, integrating a triangle wave will give a sine wave.
Do you understand the circuit you're simulating? Do you have R2 and R3 connected to the output of the first opamp? I don't see a connection dot.
What is the purpose of R6?
Thread starter | Similar threads | Forum | Replies | Date |
---|---|---|---|---|
M | Question on LM339 Simulation | Homework Help | 6 | |
Question about LM339 simulation | Analog & Mixed-Signal Design | 6 | ||
R | Comparator (LM339) Question | Digital Design | 21 | |
LM339 as PWM issue | Analog & Mixed-Signal Design | 8 | ||
T | power supply with both ics tl494,lm339 | Power Electronics | 16 |