Reducing 3.4V supply to 3.3V with simple logic

Discussion in 'General Electronics Chat' started by muthukumar_ece2004, May 26, 2011.

  1. muthukumar_ece2004

    Thread Starter New Member

    May 20, 2011
    9
    0
    Hi,
    How to reduce the 3.4V supply voltage to 3.3V with simple logic?
     
  2. Markd77

    Senior Member

    Sep 7, 2009
    2,803
    594
    A little more information please.
    Is this an analog voltage you are trying to measure, the power to a chip, other?
    Where does the 3.4V come from?
     
  3. muthukumar_ece2004

    Thread Starter New Member

    May 20, 2011
    9
    0
    Hi, this is not a analog voltage, its supply voltage. Take a care on wordings.

    In one of my project, i got 3.4V supply voltage from a regulator. But it needs to be limited below 3.4V (due to sensitive IC used in the circuit). Without changing the regulator type or property, how to reduce the 0.1V from 3.4V?
     
  4. Jotto

    Member

    Apr 1, 2011
    159
    17
    Voltage divider, or depending on the regulator you might be able to adjust that. Some regulators are adjustable.
     
  5. #12

    Expert

    Nov 30, 2010
    16,298
    6,809
    3.4 volts is about 3% high. I think you can buy regulators guaranteed to 2%.
    Mouser# 628-817B33AY-G $0.51 2% through-hole
    several more listed under LDO regulators.
    Other choice is to start with an adjustable regulator like a 317L and adjust it.
     
  6. AlexR

    Well-Known Member

    Jan 16, 2008
    735
    54
    On the other hand are you sure that your meter is reading correctly. You are looking at an error of only 3% and its just a likely that the meter is reading 3% off as that the supply voltage is 3% off.
    Frankly I wouldn't worry about a 0.1volt error as all chips do have some tolerance to supply voltage error and I would be very surprised if you chip could not handle a 3% error.
     
  7. tom66

    Senior Member

    May 9, 2009
    2,613
    214
    Most 3.3V devices can handle 3.0V - 3.6V and some can even handle 4V for a few minutes. You should be fine.
     
  8. StayatHomeElectronics

    Well-Known Member

    Sep 25, 2008
    864
    40
    Definitely check the datasheet for its supply range before making any circuit adjustments.
     
  9. magnet18

    Senior Member

    Dec 22, 2010
    1,232
    124
    If you would prefer a voltage slightly too low to one that is slightly too high I think there are some kinds of Schottky diodes with a voltage drop of .2V.
     
  10. t06afre

    AAC Fanatic!

    May 11, 2009
    5,939
    1,222
    If you are not happy with the answers. You can tell us what kind of voltage regulator, and IC you plan to connect to the regulator.
     
  11. retched

    AAC Fanatic!

    Dec 5, 2009
    5,201
    312
    A trim pot in line with the "sensitive IC" will do the trick.

    You must be sure that the trim pot is rated for the current draw of the IC.
     
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