I have a 195-210V(with ripple) power supply and I need a 180V voltage reference.

This is my best idea so far:


Instead of just connecting a resistor and 180V zener diode in series, I do it two times to get better ripple rejection.
(two zener diodes on the left of course have greater total voltage drop that diode on the right).

This solution is still far from ideal, but it's not very bad.
I think there are better solutions, but I couldn't find or invent them myself.
One obvious solution that has better accuracy would be to connect a few smaller voltage reference integrated circuits in series, and final result probably would still have better accuracy than zener diodes. However this is not a good solution since it would require much more compenents, and zener diode solution ony has 5 components.

Are there better solutions that don't require much more components?

  • \$\begingroup\$ How accurate is accurate? \$\endgroup\$ Jun 24, 2020 at 14:34
  • \$\begingroup\$ Which are you most concerned about?: (1) ripple. (2) DC average voltage accuracy. \$\endgroup\$
    – glen_geek
    Jun 24, 2020 at 14:37
  • \$\begingroup\$ @user253751 Zener diode solution has 0.4Vp-p ripple in my circuit. Therefore anything that could do better is considered accurate. \$\endgroup\$
    – J K
    Jun 24, 2020 at 14:39
  • 1
    \$\begingroup\$ Another option is to try and amplify a small voltage reference. I don't know if they make high voltage op-amps, but you could use a transistor buffer on the output, and a voltage divider in the feedback circuit. \$\endgroup\$ Jun 24, 2020 at 14:47
  • 1
    \$\begingroup\$ Just put a capacitor of some reasonable value across the zener or, split the 10 kohm resistor in two and put the capacitor at the centre point to ground. What frequency is the ripple and what accuracy for the voltage reference? \$\endgroup\$
    – Andy aka
    Jun 24, 2020 at 14:51


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