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

Passive MOSFET bridge rectifier

Status
Not open for further replies.
E

electronZ

Member level 2
Joined
Apr 11, 2010
Messages
43
Helped
0
Reputation
0
Reaction score
0
Trophy points
1,286
Activity points
1,602
Hello all, :)

I want to use a passive MOSFET bridge rectifier as reverse-polarity-protection circuit. I stumbled on a circuit topology based on four MOSFETs - 2x n-channel MOSFETs and 2x p-channel MOSFETs.
Principle of operation is pretty straight forward. Here is the diagram:
MOSFET rectifier.png
I want around 230 mA at 5 V. The simulation results confirms my understanding, I read 5 V across RL.

However when I measure it on the breadboard, the voltage across RL is only around 3.4 V :/
I am using 2x IRF7319, here is the datasheet: http://skory.gylcomp.hu/alkatresz/irf7319.pdf

Am I missing something here? what is wrong?

Thanks a lot :)
 

Are you certain that you wired the actual circuit correctly?
You may have the MOSFET body diode voltage drops to account for (2) when current is flowing in RL, e.g. the pin "2" of RL is not actually at ground (potential of the negative plate of the DC source) but diode drop above it).

Take a DMM and measure voltage drops around the loop.
 
Thanks a lot...
The strange thing is that it works with a 1 kOhm - I get 4.95 V. It is as soon as I start to load the circuit with the 22 Ohm load, the voltage drop to around 3.4 V.

I will double check the connections and measure the voltages in the loop.
 

crutschow said:
Is the 5V input still 5V with a 22Ω load?
Click to expand...

Yes.
I found the problem... The freaking breadboard!? I soldered everything, and the circuit works like a charm - very close values to results extracted from simulation.

It works, thanks everybody <3
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top