# Diode Array for Full-Wave Rectifier for PoE

I was looking for SCHOTTKY diode for designing Full-Wave Rectifier for PoE. I was searching for the diode but came across the term Diode Array. After applying filter for my specification, I found the one. The diode that I found considering cost and specification is over here. Is there any preferred configuration of diode array like independent, common-cathode or anode, maximum number of diode in single package?

I would like to know what are advantage and disadvantages of using diode array over normal diode. Which one is preferred for Full-Wave rectifier for PoE application? Is there any standard?

EDIT:

My Specifications are:

Reverse Voltage Protection: Atleast 40V (Considering Full-Wave bridge-Rectifier)

Average Current: 500mA

Forward Voltage Drop at 500mA pr above: As less as possible.

There are many choices and the usual tradeoffs are heat, cost, Vr vs Vf@If and all Diodes create a heat loss issue vs cost.

Therefore I would consider a better solution to use a MOSFET bridge but your cost spec is undefined. Lead-time is another tradeoff with 12wks for this \$0.07 half bridge diode array. from prev. link to datasheet.

Classic solution , inefficient.

Improved way, lossless

Ref

• Can you explain Vr vs Vf@If ? – abhiarora Sep 20 '18 at 16:36
• Schottky diode peak inverse repetitive or reverse DC voltage of 20, 40, 60 80, 100V etc also increases Vf at 1A by similar proportions. 0.3, 0.35,0.4, 0.45 or something like this. – Tony Stewart Sunnyskyguy EE75 Sep 20 '18 at 17:24
• See updated answer graph – Tony Stewart Sunnyskyguy EE75 Sep 21 '18 at 0:40

A diode array can save you money and board space.

But I don't think a common cathode array like you selected is especially useful in a full bridge, since only two of the diodes are in common cathode configuration.

You can look for a series connected one like this:

Or just an isolated array:

You might even find a full bridge array like this one:

Unfortunately the one I found doesn't meet your 40 V reverse requirement.

• Vf vs Vr is a significant tradeoff and thus more heatloss. – Tony Stewart Sunnyskyguy EE75 Sep 20 '18 at 16:35