Which biopolar transistor to use for switching higher currents using microcontroller

[Farukh Khan]

Hello,

I am designing one of my regulator circuit using LM2678T-ADJ regulator. Now the thing I came up with is I want to turn on or off the whole regulator circuit using a biopolar transistor like 2N2222A with my Arduino UNO R3. But my regulator circuit will consume about 5A of current at peak but the 2N2222A is rated for 800mA only from the emiiter to the collector according to it's datasheet. So I tried looking on some mosfets like 2N3055 which are rated for higher current switching. But these mosfets also need more current and also volt on the base to turn the path on which my Arduino UNO R3 or normally any other microcontroller can provide. So my question is what transistor I can use to switch higher currents with lower signal from microcontrollers like arduino?


Please help me out guys.
Thanks in advance......

 

[CDRIVE]

Why can't you use the ON/OFF pin?

Chris

 

[Farukh Khan]

I really got no idea about the ON_OFF Pin and how to control the power of the circuit using this pin. Can you please provide me a good guide by following which I might use the ON_OFF pin on LM2678T-ADJ to control my buck convertor or regulator using arduino uno r3 microcontroller.


Thanks in advance.....

 

[davenn]

from the datasheet ... they are good things to read to learn about devices being used in a project


ON/OFF


This input provides an electrical ON/OFF control of the power supply. Connecting this pin to ground or to any voltage

less than 0.8V will completely turn OFF the regulator. The current drain from the input supply when OFF is only

50μA. Pin 7 has an internal pull-up current source of approximately 20μA and a protection clamp zener diode of 7V to

ground. When electrically driving the ON/OFF pin the high voltage level for the ON condition should not exceed the 6V

absolute maximum limit. When ON/OFF control is not required pin 7 should be left open circuited.


So you could control this pin from one of the microcontroller's outputs by providing either a high or a low



Dave

 

[Farukh Khan]

Thanks a lot for this reply. Really helped me a lot.

Thanks a lot guys.

 

[CDRIVE]

Dave, you must be feeling better. Glad to see that!

Chris