15v to 24v level shifting

Discussion in 'General Electronics Chat' started by ak52, Mar 5, 2016.

  1. ak52

    Thread Starter Member

    Oct 15, 2014
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    Hello everyone,
    I am trying to find a good level shifter which converts a 15v signal to 24v signal.I have tried many vendors but they don't seem to have it.
    If anyone is using such an IC or an equivalent signal,please share the part numbers.

    Many thanks,
    AK
     
  2. #12

    Expert

    Nov 30, 2010
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    Is that 15 volts RMS, peak to peak, DC, or some other thing?
     
  3. ak52

    Thread Starter Member

    Oct 15, 2014
    145
    4
    It is a DC value.
     
  4. #12

    Expert

    Nov 30, 2010
    16,261
    6,768
  5. ak52

    Thread Starter Member

    Oct 15, 2014
    145
    4

    No no,I am not looking for a Switching regulator,I need a level shifter,something like the "MC14504BDG",but with 15v to 24v ratings
     
  6. #12

    Expert

    Nov 30, 2010
    16,261
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    That's a digital hex level shifter. I'm not good with digital. I would just make one with transistors, but that's because I'm not good at digital chips.
    Now that we know you are NOT looking for a DC converter, somebody else might know the answer.
     
  7. crutschow

    Expert

    Mar 14, 2008
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    You can just use a common-emitter BJT inverter circuit with a 24V supply to the collector load resistor.
    That, of course, inverts the signal so, if that is as problem, you would need a logic inverter added to the input to the transistor or connect two of the transistor stages in series.

    If you have a number of these signals to convert you could use a transistor array.
     
  8. Papabravo

    Expert

    Feb 24, 2006
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  9. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    If signal inversion is ok, you can get 7 level translators that will go from 6 V to 50 V in a ULN2004, 8 or them in a ULN2804. Putting two stages in series will get the logic polarity back to normal.

    What is the speed or risetime requirement for the output signal? Is an open collector and a pull up resistor ok, or do you need a totem pole output?

    ak
     
  10. Papabravo

    Expert

    Feb 24, 2006
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    It is really hard to give definitive answers when the requirements are unclear. You get what you ask for.
     
  11. AnalogKid

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    On another forum I'm getting spanked by a newbie for making that point.

    Rule number one of AAC: please talk about AAC with all of your friends.
    Rule number two of AAC: No schematic, no answer.

    ak
     
  12. dl324

    Distinguished Member

    Mar 30, 2015
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    24V isn't a common digital logic voltage. How many signals do you want to level shift? If it's a few, you can build buffers using discrete transistors. If you have a lot, using a CD4069 to do the first inversion would cut down on the number of transistors you'd have to wire.
     
  13. AnalogKid

    Distinguished Member

    Aug 1, 2013
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    I've seen it in industrial control and PLC stuff, enough to know that a darlington driver works.

    ak
     
  14. crutschow

    Expert

    Mar 14, 2008
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    You must sink 1.6mA of current when generating the input low of 0.8V.
    The 7407 also requires a 5V supply and the input high limited to 5.5V maximum.
     
  15. Papabravo

    Expert

    Feb 24, 2006
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    I suppose you could make what you need from an LM393 or LM339. Wide common mode range, adjustable threshold, and open collector output.
     
  16. crutschow

    Expert

    Mar 14, 2008
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    That seems a good solution.
    You get two comparators in the LM393 package and four comparators in the LM339 package, and they will operate with up to a 36V supply.
    You could use 2 resistors to set the input trigger threshold for all the comparators and 1 pull-up resistor from each output to the 24V supply.
     
  17. ak52

    Thread Starter Member

    Oct 15, 2014
    145
    4
    Thanks guys for all your replies,i was hoping for a single IC solution ,but for this situation i don't think it exists,\
    I found one which does what i want ,but i have to check it in real time,"VNQ860-E".
     
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