Increasing current of a digital signal

Thread Starter

Saurabh.30

Joined Apr 27, 2021
6
Hi,
I am working on a project which require to increase the current of a 5v high speed digital signal from 20ma to 100-150ma. can someone help me how to achieve that

Thanks
 

andrewmm

Joined Feb 25, 2011
1,757
Easy answer is you need a buffer,

to point you in right direction,
what voltage out , what is the edge speed you need ( bandwidth )
and anything else you can tell us about the load,
Relay, led , laser , resistor or what ?
 

BobTPH

Joined Jun 5, 2013
3,690
What is the load and what is high speed?

Does it have to sink current or source it or both?

It could be as simple as a BJT or MOSFET used as switch.

Bob
 

Ian0

Joined Aug 7, 2020
3,280
If you just need more current, but only 5V, then all 4 sections of a 74AC125 would do 100mA and still have the speedy rise/fall times.
A 74AC541 won‘t gain much more, as you reach the supply pin limits.
 
Last edited:

Thread Starter

Saurabh.30

Joined Apr 27, 2021
6
Easy answer is you need a buffer,

to point you in right direction,
what voltage out , what is the edge speed you need ( bandwidth )
and anything else you can tell us about the load,
Relay, led , laser , resistor or what ?
output is from Arduino so it'll have variety of loads
 

Ian0

Joined Aug 7, 2020
3,280
output is from Arduino so it'll have variety of loads
So you have a variety of answers depending on the load:
for push-pull 3.3V or 5V logic up to 100mA at full speed = paralleled sections of 75AC125
for push-pull up to 18V with 30ns rise-time = MPC1401
for single ended with load connected to a higher voltage = single MOSFET - choose MOSFET Vds/Id to suit load
for single ended with load connected to a higher voltage but slower = bipolar transistor.
 

Thread Starter

Saurabh.30

Joined Apr 27, 2021
6
So you have a variety of answers depending on the load:
for push-pull 3.3V or 5V logic up to 100mA at full speed = paralleled sections of 75AC125
for push-pull up to 18V with 30ns rise-time = MPC1401
for single ended with load connected to a higher voltage = single MOSFET - choose MOSFET Vds/Id to suit load
for single ended with load connected to a higher voltage but slower = bipolar transistor.
cannot find anything for "75AC125" can you please elaborate
 
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