Email: Password: Remember Me | Create Account (Free)

Back to Subject List

Old thread has been locked -- no new posts accepted in this thread
???
12/18/07 18:54
Modified:
  12/18/07 18:58

Read: times


 
#148468 - OK, like this
Responding to: ???'s previous message
for simplicity I show this for a 0-2V input A/D you can convert for whatever swing you have, just keep the "SOLID reference" at 1/2 max A/D input.
input (+-20V)- 20k -*- A/D input (will swing between +41/21V and 0V)
                    |
                   | |
                   | | ik
                   | |
                    |
SOLID 1V reference -*
With this resistive divider, you will not have a "speed demon", but should easily manage 20k+ samples/second.

remember that the SOLID reference must both supply and sink, I would use a zener to ground and ~330 ohms to Vcc.

Erik

List of 28 messages in thread
TopicAuthorDate
LPC936 with External A/D            01/01/70 00:00      
   Another ADC or a multiplexer            01/01/70 00:00      
      Every 2 seconds            01/01/70 00:00      
         what type of analog signal you are talking about?            01/01/70 00:00      
            I would not, but            01/01/70 00:00      
         Easy            01/01/70 00:00      
            a corrective addition            01/01/70 00:00      
         74HC4051/74HC4052/74HC4053            01/01/70 00:00      
            BUT            01/01/70 00:00      
               Then again            01/01/70 00:00      
   Negative readings            01/01/70 00:00      
      Datasheet!            01/01/70 00:00      
         can you please be specific            01/01/70 00:00      
            negative readings?            01/01/70 00:00      
            Not allowed?            01/01/70 00:00      
      Negative ADC readings - again            01/01/70 00:00      
   Like this            01/01/70 00:00      
      I do not understand            01/01/70 00:00      
      BANG!!            01/01/70 00:00      
      In General            01/01/70 00:00      
         Another BANG!            01/01/70 00:00      
            I assumed            01/01/70 00:00      
               Looks like it cannot be done.            01/01/70 00:00      
                  you can            01/01/70 00:00      
                     Exlain            01/01/70 00:00      
                        OK, like this            01/01/70 00:00      
                           Thanks            01/01/70 00:00      
                              or you can use opamp as non inverting summing amp.            01/01/70 00:00      

Back to Subject List