how to implement volatges selected?

[mendenz]

l have two voltage signals ne is constant 3.3v ,and the other one is vared from 0 to 15.5.
how can i implement the select function by the hint of a digital signal?
For example:if the digital signal is high, we choose the varied voltage signal , inversly we choose 3.3v.

 

[ptmsl]

Depending on your appliation (current drawn, acceptable voltage drop, isolation needed) you can use mosfet switches or BJT switch or potocouplers driven by inverted digital signals. Can you give me more info on your application?

 

[hossein samani]

hi
lets see ..u can do it very simply just by two relays.
if the signal is high one relay that is connected to the first voltage is active and the voltage goes to the output
and when the input is low another relay is active and another voltage goes to output.u can control it by just one not gate and transistor in out put.
i think it is the best way.

 

[suria3]

You can apply the pass transistor (transmission gates) circuit in order to do selection voltages.

 

[mendenz]

lt's a eeprom ip design
we must used the selected voltage as the voltage source of circuits.
so the voltage drop must be as small as possible and the driver ability must't be effected.

Depending on your appliation (current drawn, acceptable voltage drop, isolation needed) you can use mosfet switches or BJT switch or potocouplers driven by inverted digital signals. Can you give me more info on your application?

 

[ptmsl]

Best use relays unless the responce time of the contacts is critical. To drive the relays you can use a series ULN2001 to ULN2004 relay drivers that are designed to interface to logic circuits.

 

[hasanbarim]

you can use 4052 anolog multiplexer there are several brands of this mux you can select the multiplexing inputs by digital signal(use a optocoupler switch) and mux will convey the analog signal in its inputs to its output according to the selection bits.