Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

+12V source switching (lowest part count, lowest cost)

Status
Not open for further replies.
J

Jester

Full Member level 6
Full Member level 6
Joined
Aug 18, 2012
Messages
377
Helped
7
Reputation
14
Reaction score
7
Trophy points
1,298
Location
.
Activity points
4,754
I have done this a few times and the end solution never looks elegant.

I need to switch (control) a 500ma, +12V source ( with 5V logic). The switch must Source not sink.

Please show me your elegant solutions.

Here is a 4 component $0.40 solution

cheap.png
 

Well you are using P channel Mosfet that will not work as I can see. Use NPN BD 139 Transister.
 

Jester said:
I have done this a few times and the end solution never looks elegant.

I need to switch (control) a 500ma, +12V source ( with 5V logic). The switch must Source not sink.

Please show me your elegant solutions.

Here is a 4 component $0.40 solution

View attachment 108620
Click to expand...
what is the issue than ? yo uonly need to choose the right component rating, your circuit work perfectly
 

Last edited:

yassin.kraouch said:
what is the issue than ? yo uonly need to choose the right component rating, your circuit work perfectly
Click to expand...

Yes it works, but can it be done with less than 4 components?
or
with less expensive components
or
both

- - - Updated - - -

SunnySkyguy said:
Here is a 1 part SOT-363 165 mOhm $0.09 High Side 1A switch with extra parts for slew rate control. +/- 1.1A

View attachment 108625
Click to expand...


Ding Ding Ding Ding Ding Ding ...... we have a winner

1/2 the parts in a small package for cheap:)

The +12V output will be connected to the load by the end user (ESD what's ESD?). Any suggestions for protection?

Thank you SunnySkyguy :)
 
Depending on some secondary values / concerns, a 5V
reed relay can be a nice simple and fairly reliable option.
Not as high a cycle reliability, but more resilient to some
overstress conditions (and providing isolation between
control and load, if that kind of thing matters).
 

Electro-Static-Discharge = ESD . This part has protection with intrinsic diodes.

- - - Updated - - -

This is a half bridge (complementary) emitter follower. THis is equivalent to SPDT between V+ and gnd but with Vce-saturation voltage drops and use where low impedance is but voltage drop is not as important.
 

SunnySkyguy said:
Electro-Static-Discharge = ESD . This part has protection with intrinsic diodes.

- - - Updated - - -

This is a half bridge (complementary) emitter follower. THis is equivalent to SPDT between V+ and gnd but with Vce-saturation voltage drops and use where low impedance is but voltage drop is not as important.
Click to expand...

I guess you did not catch my dry humor about ESD, I have had very limited success persuading most end users to take any ESD precautions with electronic equipment.
 

Hi,

If low side switching is possible, then a single n ch mosfet with low vgth will do.

Klaus
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top