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I'm working on a nixie clock based on a STM32L476RG microcontroller and HV5530 chips. The microcontroller uses 3.3 V logic while the HV5530 really needs 12 V logic, which is a pain to implement. There are buffer ICs that raise the level from 3.3 V to 5 V, but I was unable to find any that works with 12 V. I experimented with a circuit based on the LM339 with a reference voltage of 0.6 V generated with a forward biased diode and pullup resistors to 12 V. It works, but I prefer to use a single chip. I've spent hours online trying to find a chip that does this, but none comply with 12 V output. I looked for both open drain outputs or push pull outputs without success.

Is there a single chip that does 4 channel, one way shifting from 3.3 V to 12 V?

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  • \$\begingroup\$ What speed do you need? \$\endgroup\$
    – winny
    Dec 29, 2019 at 16:47
  • \$\begingroup\$ Just one example: ti.com/lit/ds/symlink/sn7406.pdf \$\endgroup\$
    – sstobbe
    Dec 29, 2019 at 18:45
  • \$\begingroup\$ Not single chip BUT can be VERY compact. 4 NPN transistors. Each collector via R to 12V. Inputs to emitters. Bases to 3V3 via an R - MAY be able to combine all 4 bases and use a single R for bases. Total 4 x NPN (array or tiny pkgs), 4 x pullup Rs to 12V if destinations do not self pullup. One or 4 base Rs. \$\endgroup\$
    – Russell McMahon ♦
    Jan 1, 2020 at 2:45

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You're looking for a 74HCT input (1.5V threshold) with CD4000B outputs which do not exist.

But fortunately CD4000B's have level-shifters that work from 3 to 15V. or even 18 to 20V

One of them is the CD40109B .

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  • \$\begingroup\$ I came across the CD40109B, but I think my conditions are outside the recommended operating boundary specified in the datasheet. The chip doesn't even have specs for 3.3 V. Do you think it is safe to use in my circuit? \$\endgroup\$
    – Stelian Saracut
    Dec 29, 2019 at 18:03
  • \$\begingroup\$ But you didn't specify load capacitance and rise time so beware CD4000 is about RdsOn= 2k to 3k at 3V and then 300 Ohms at vs 3.6V logic is 25 Ohms \$\endgroup\$
    – Tony Stewart EE75
    Dec 29, 2019 at 18:11
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    \$\begingroup\$ Update: I tested the CD40109B and it works in my circuit. \$\endgroup\$
    – Stelian Saracut
    Jan 16, 2020 at 21:34
  • \$\begingroup\$ atta boy Stelian \$\endgroup\$
    – Tony Stewart EE75
    Jan 16, 2020 at 21:36

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