zionico90
Member level 2
Hi guys,
I have a common (I think) question related to the design of a schmitt trigger by using op-amp. In details I have to design a trigger with thresholds equal to +/- 1 V.
In order to do that, from the equation I have obtained that the ratio between the two resistance should by 14. Then I have realized the circuit by using R1= 4 Ohm (2.2+1.8) and R2 = 56 Ohm. For testing I have used a sinusoidal input (5Vpp and 1 kHz) and it seems that the circuit works with the proper thresholds. The problem is that when the state is "low" or "high", the op-amp saturate at V = 28.5 V! But the op-amp (TL081CP) is supply with a symmetrical +/- 15V.
Does anyone know where I'm wrong?
Thanks!
I have a common (I think) question related to the design of a schmitt trigger by using op-amp. In details I have to design a trigger with thresholds equal to +/- 1 V.
In order to do that, from the equation I have obtained that the ratio between the two resistance should by 14. Then I have realized the circuit by using R1= 4 Ohm (2.2+1.8) and R2 = 56 Ohm. For testing I have used a sinusoidal input (5Vpp and 1 kHz) and it seems that the circuit works with the proper thresholds. The problem is that when the state is "low" or "high", the op-amp saturate at V = 28.5 V! But the op-amp (TL081CP) is supply with a symmetrical +/- 15V.
Does anyone know where I'm wrong?
Thanks!