Direct Current switching

[thavamaran]

Hi guys. I recently posted to discuss on switching signals. I have resolved that.

Now, Im trying to switch a DC voltage/current.

Say Im supply a DC stable bias current of about 40 mA. If I want to switch it off at certain time interval, maximum of 40 us. Which means, the maximum pulsewidth of the control pulse will be 40 us.

After 40 us, I don't want any direct current to go through the switch.

Can anyone suggest a switching IC operates at this region? I googled it, and I dont seem to get a right answer.

Any advice please?

 

[vimalkhanna]

Use a CMOS logic 4066 for analog and 547 /337 after this .
Alternately , use a LM555 as pin 3 can switch off within 1usec.
You can use a 234 which is open collector output

 

[SherpaDoug]

What voltage level are you switching? 1V? 1000V? It makes a difference!

If you are in the 3V to 5V range would a MAX890 do? It switches off in 5us, though it takes 200us to switch on.

 

[thavamaran]

Hi vimalkhanna. Thanks for your reply. Can you explain please how this CMOS logic 4066 works and why need 547/337 after this? Also can you specifically state what is 547 or 337 please? Thank you very much.

---------- Post added at 10:42 ---------- Previous post was at 10:39 ----------

Hi SherpaDoug... Voltage is not specific, cause im generating a DC current from a stable bias supply specifically made for biasing laser. Therefore it does not indicate voltage but just current.

I believe that if I generate a 40 mA current, and SMA cable terminates about 50 ohm and that gives us about 2V (Ideal). Im gona switch it off with a control pulse. So it should switch on at the rising edge and stay on for 40 us and switch off at the falling edge and switch off forever.

Please let me know if you need clearer explanation, thanks a lot for your help.