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Analog switching between two sources 5V/1A and 5V/2A

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Dino1400

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Hello everyone,

I'm trying to switch between two sources 5V/1A and 5V/2A based on a decision circuit (a compactor: if high close 5V/1A else close 5V/2A).

can anyone have an idea of how to design these switches (could ne some NPN an PNP).

please see attached picture.

Thank you in advance.

IMG_5070.JPG
 

Depends on how fancy you want to be. Do you need to worry about both switches being on momentarily during a switch-over? You could use a P-channel mosfet and drive the gate with your comparator output.
 

the first thing that came to my mind is to use either PNP+NPN or N-channel +P-channel but I'm not sure how reliable this idea.
I have attached both approaches please provide me with your though and comment and it there is a better approach i will appreciate your help IMG_5071.JPGIMG_5072.JPG

- - - Updated - - -

Thank you for your prompt replay. Is AM1 and AM2 connected to the charger box, can you send me some explanation of this circuit looks very interesting.
 

Those are a little too simplistic. For one thing, your n-ch fet will always conduct because of its intrinsic diode. Use two p-channels and two complimentary gate drives
 

I'm thing about using a part from Texas Instruments
TS5A3157 10-Ω SPDT Analog Switch
I just need to figure out how to use it in my circuit.

Can you provide a drawing for your suggestion or if you have used something before like TS5A3157 or simular part.

Thank you again
 

I used 10 V for the charger since the PMOS needs high level gate drive. You need to use the logic gate types.
 

10 ohm?
Do the math....how much voltage will you drop at 2 amp current with a 10 ohm switch?
 

I'm thing about using a part from Texas Instruments
TS5A3157 10-Ω SPDT Analog Switch
I just need to figure out how to use it in my circuit.

Can you provide a drawing for your suggestion or if you have used something before like TS5A3157 or simular part.

Thank you again

Good luck, you'll be dissipating 40 watts across that sucker.
 

post #2 is a good proposal i just needed some more details and explanation.
I also Asked If anyone asked have TI TS5A3157 SPDT Analog Switch or SGM3157YC6 which is Capture3.PNGCapture2.PNGCapture.PNGbased on MOSFET swiching in one IC package.
 


Hello all,

I'm posting a circuit that I thinking to use to switch between two power supplies.
Please If you have any comment or better suggestion I will really appreciate that.

Thank you in advance.
Dino

Capture11.jpg
 

Hello all,

I'm posting a circuit that I thinking to use to switch between two power supplies.
Please If you have any comment or better suggestion I will really appreciate that.

Thank you in advance.
Dino

View attachment 137057
Sure. Did you give up on trying to design a more reliable, less expensive proper solid-state solution?
 
I have not give I just talk to colleague of mine said to keep it simple as you can. I like to use different solution of course I like the proposal from post #2.

I attached here again with a minor modification.

IMG_5085.JPG
 

Those MOSFETs should be P channel and logic level... if you want it to work. What is the comparator's output voltage ?
The FDG332PZ, P channel mosfets from post #2 looks OK.
 
Last edited:

thank you for your response, the comparator's voltage should be 5V.
 

thank you all
and special thanks to E-design and Catam
 

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