Is there a diode that has 0.2V forward voltage drop?

[wwwrabbit]

low forward voltage drop diode

Please tell me. I searched Web, there are 1N34, 1N60, 1N277 Ge diode, but there FWD drop is big.

Thank u

 

[flatulent]

0.2v diode

Ge diodes are small signal. You may be finding data sheets for replacements made from Si, or ones with Max values for high currents.

 

[instruite]

diode 0.2v

Forward voltage varies with the forward current
It also depends on the temperature
So if you can specify your requiriments it will be easy to give you a particualr diode number

you can also try searching for schottkey diodes oon various diode suppliers
We normally use NEC diodes (so you can try checking there datasheets)
www.necel.com

 

[wwwrabbit]

max voltage drop diode 0.2v

I use this diode as a switch, only allow 3.3V go one direction, and when use USB as a power supply, this diode will block the current go to LM2937's out put. so I want this diode has less forward voltage drop. I know Ge diode usally drop 0.2V while Si diode drop 0.7V. When I see 1N34 datasheet, it says FWD drop is max 1.0V, I was confused.

Thanks for your anwser

 

[VVV]

0.2 v diode clippers

You have to use a power Schottky diode. That will give you about 0.2V at a reasonable current. Check out this datasheet **broken link removed**

There are also specialized ICs that control a MOSFET and keep it on for an on drop of about 50mV. As examples, LTC4411, with internal MOSFET www.linear.com/pc/productDetail.do?navId=H0,C1,C1003,C1142,C1079,P2430
LTC4412, with external P-ch MOSFET www.linear.com/pc/productDetail.do?navId=H0,C1,C1003,C1142,C1079,P2220

You can try to build a similar circuit yourself, using an opamp and a MOSFET, but there are many things to consider. The idea is that it works like a regulator, maintaining actually a low voltage drop across the MOSFET, instead of the load as a normal regulator would do. Then, as the voltage across the MOSFET begins to decrease (because you connected another power source at the output) the MOSFET is switched completely off.
Again, it isn't really that easy, when you consider all the factors, including opamp supply voltage and its required common mode range. You will need a RRI opamp, or a separate supply (which kind of defeats the purpose).

 

[breadpig]

hi i need a 0.2v forward voltage drop diode(used as a full bridge rectifier) with about 1amp current rating. any suggestion which model?