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Kai Klaas
03/16/12 06:38
  03/16/12 06:42

Read: 547 times

#186725 - So, you need to make -15V, 0V and +15V?
Responding to: Mehdi's previous message
Hy Mehdi, how are you?

How precise must these voltages be fabricated? What load has to be driven by these voltages? How fast must the signal settle after a change?

Your scheme is good but will only work, if both outputs have push-pull-stages, which the standard 8052 does not provide. So, you might need to use two separate 74HCMOS inverters for that job, like in the 74HC04 e.g.

If the voltages have to be fabricated precisely you should increase the both resistors (R9) a bit because of the unwanted voltage drops within the inverters. Or take some inverters in parallel.

If the signal has to drive a heavy load you could use the L165 or similar as driver.

Kai Klaas

List of 21 messages in thread
Making a pulse with 3 different voltage level!      MEHDI      03/15/12 10:57      
   No best but consider a voltage divider        Per Westermark      03/15/12 11:02      
      derivative with a DAC?      Erik Malund      03/15/12 11:07      
   derivative with configurable ports        Erik Malund      03/15/12 11:10      
   Thanks Per And Erik      MEHDI      03/15/12 11:44      
      which derivative      Erik Malund      03/15/12 12:12      
      with an OPamp      Erik Malund      03/15/12 12:16      
         Thanks Erik      MEHDI      03/16/12 01:57      
      So, you need to make -15V, 0V and +15V?      Kai Klaas      03/16/12 06:38      
         Hi Dear Kai      MEHDI      03/16/12 09:45      
         74hc series      MEHDI      03/17/12 12:50      
            FPGA      Kai Klaas      03/17/12 14:58      
      I think you can do it wih one resistor.      David Prentice      03/16/12 11:09      
         Most 8051 Systems?????      Michael Karas      03/16/12 18:51      
            Well add a pull-up resistor then      David Prentice      03/17/12 02:34      
               Would prefer to not have to match internal resistors      Per Westermark      03/17/12 06:48      
               You cannot match the weak internal active pull-up!      Kai Klaas      03/17/12 07:02      
                  Being pedantic.      David Prentice      03/17/12 09:12      
         Hi David      MEHDI      03/17/12 12:43      
   maybe a couple of mosfets ...      Richard Erlacher      03/15/12 16:30      
      Thanks Richard      MEHDI      03/16/12 02:02      

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