I am trying to simulate IR2110 high and low side driver, but I get very odd bugs - simulation result varies just by changing simulation stop time or saving, exiting and then reloading program. I am using this library for both IR2110 and mosfets. Is there a better library? Also - why in some examples of such driver there are two capacitors - one polarized and another not? This is my drawing:

  • 2
    \$\begingroup\$ C4 is 5000 µF. I don't know if that's what causes the issue, but it's way too high. \$\endgroup\$
    – Oskar Skog
    Sep 15, 2021 at 11:51
  • \$\begingroup\$ Minimum value is 300uF - anything lower and I get poor gate output wave. \$\endgroup\$
    – Ri Di
    Sep 15, 2021 at 12:33
  • \$\begingroup\$ But again - I cannot even test this properly - after 10-200ms I get "Time step too small" \$\endgroup\$
    – Ri Di
    Sep 15, 2021 at 12:35
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    \$\begingroup\$ @RiDi That's absurd. The bootstrap capacitor is usually 100n...1u. Change it to 1u and try again. You should also add a .model to your diodes, or use ones from the database. Try BAT54, for example. Also, your half-bridge with load is not very well connected... \$\endgroup\$ Sep 15, 2021 at 13:27
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    \$\begingroup\$ Fix the circuit and take a look here forum.allaboutcircuits.com/threads/… \$\endgroup\$
    – G36
    Sep 15, 2021 at 14:47

1 Answer 1


I assume that you really intend to make a short through R3 every time the driving signal is high? This cannot work. The IR2110 does not invert the low side switch, see figure 1 on page 6 in the DS. To drive the high side, you need the high side off and the low side on, in the first place, to charge the bootstrap cap, which will supply power to the high side when it's time comes. Your HIN should be 180 degrees out of phase with LIN, I guess...

  • \$\begingroup\$ thanks. did not know that. I thought they could be both operated at same time \$\endgroup\$
    – Ri Di
    Sep 16, 2021 at 13:17

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