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I have a simple triangle generator circuit soldered and powered by 5V rails shown below. Verified by simulation and equations, it should output a 500kHz triangle wave a \$\pm4.2V\$. Instead, the only thing visible at the output is the power supply noise with additional high frequency noise at the peaks.

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It seems like the issue is with the supply rails. The power supply is showing 5V but at the terminals on the board i'm seeing +1.8V for the positive rail and -3.2V for the negative rail. What is the cause of this and how is it possible for this circuit to bring down the supply rails?

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  • \$\begingroup\$ You win the arbitrary sig. gen award of the year. (lol) asymmetric 40Hz (?) with a chirp burst carrier, but at least you a have a 5.0Vpp avg swing. Is that your integrator output on U1A? U need 0V on U2-5. U1-3 and then +5, -5 with caps. When in doubt, check every pin against spec.. \$\endgroup\$ – Sunnyskyguy EE75 Jun 5 at 12:32
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I have a simple triangle generator circuit soldered and powered by 5V rails

Given that you said "rails" and not "rail" AND that you said the output should be +/- 4.2 volts I have to assume you are attaching +/- 5 volts to the circuit. If you are then you have probably destroyed the LT1719 because it's maximum supply voltage (Vs to GND) is 7 volts and not 10 volts: -

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  • \$\begingroup\$ This is incorrect: VCC to VEE (LT1719 S8 ) ... 12V \$\endgroup\$ – Huisman Jun 5 at 11:24
  • \$\begingroup\$ @Huisman don't be so hasty with this - read the data sheet and note that pin 8 in the circuit connects to +5 volts and pin 5 connects to - 5 volts - those pins (Vs and GND) should not exceed (or be close to) 7 volts. \$\endgroup\$ – Andy aka Jun 5 at 11:25
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    \$\begingroup\$ You're right. +1 for detecting it. I should better read OP's circuit. It's a nice example that Vee =/= GND and Vs =/= Vcc \$\endgroup\$ – Huisman Jun 5 at 11:29
  • \$\begingroup\$ @Andyaka ah, thanks for that catch. Does there exist such a comparator that can output Vcc to Vee? Or is it not possible to create a triangle generator circuit where the comparator outputs +/-5V. \$\endgroup\$ – dos584 Jun 5 at 22:41
  • \$\begingroup\$ Try and find a decent of amp that can work on a single 5 volt rail and bias the mid rail to be 2.5 volts is my advice. \$\endgroup\$ – Andy aka Jun 5 at 22:49

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