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From my understanding of shoot-through, I think this circuit will shoot-through every cycle of pulse and destroy itself.

  1. Will it shoot through or are there any hidden elements to prevent it?
  2. Can I make discrete CMOS logic based on this circuit? Or which circuit will work?
  • 1
    \$\begingroup\$ If Vgs(th) is about Vdd/2, there will be no shootthrough. Guaranteeing this with discretes is your problem... \$\endgroup\$ – Brian Drummond Sep 7 '20 at 21:16
  • \$\begingroup\$ The CD4069 datasheet shows its fairly low typical shoot-through current. But I cannot add the image from the datasheet. A 74HC shoot through current is much higher and causes destruction if the switching speed is too slow. \$\endgroup\$ – Audioguru Sep 7 '20 at 21:39
  • 2
    \$\begingroup\$ Strategies exist to mitigate it to the point where it typically costs power not damage, but there is shoot through in many CMOS structures; it's why you don't want an input sitting at an intermediate voltage where both upper and lower FETs are a little bit on. \$\endgroup\$ – Chris Stratton Sep 7 '20 at 22:01
  • \$\begingroup\$ I imagine a difference in capacitance between the two mosfet gates can create a short delay avoiding shoot through. \$\endgroup\$ – Fredled Sep 7 '20 at 23:35

I've guided design teams, to produce control logic with minimal upset to VDD caused by logic transitions. The key

  • use long channel CMOS --- may be 5nanosecond Tpd instead of 50pS Tpd

  • operate the CMOS gates/FFs at reduced VDD (not 5 volts)

  • have an RC filter between global VDD and the LOGIC VDD: 100 pf and 100 ohms

  • have controlled_slew output driver(s)

Result? passed FCC emissions on first_test.

  • \$\begingroup\$ then I can't create this circuit with narmal mosfet? \$\endgroup\$ – M lab Sep 8 '20 at 5:46

Here is an image of fairly enter image description herelow shoot-through current in the datasheet of a CD4069:

  • \$\begingroup\$ So, how these happen? I think if I grab some mosfet and rebuild this circuit it certainly destroy itself. \$\endgroup\$ – M lab Sep 8 '20 at 5:44

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