Ideal diode alternative - Page 1
Forum section: electronics / beginners

author: Vindhyachal.takniki
author_rank: Frequent Contributor
timestamp: February 12, 2015, 11:02:47 am
content: I have to place a ideal diode in my circuit. ideal didoe means very low power.My applicaiton is to to reverse polarity protection. Vin = 20V max & Iout = 1A max.Application is power & space critical.1. I have searched for LTC4411. part is very good with 40uA at 3.6V & 100mA. & comes in S5 package.2. Just wondering, if anyone had better part alternative or any other part.

author: PeterFW
author_rank: Frequent Contributor
timestamp: February 12, 2015, 12:19:32 pm
content: Quote from: Vindhyachal.takniki on February 12, 2015, 11:02:47 amDo you just want just a reverse battery protection or a power source switch?If you just want to add a diode in series with the power input you can use a P-Channel FET wich is, as far i know, the simplest and most efficient way to do this.Depending on the additional circuit, this the best solution to your problem:http://hackaday.com/2011/12/06/reverse-voltage-protection-with-a-p-fet/

author: free_electron
author_rank: Super Contributor
timestamp: February 12, 2015, 01:39:04 pm
content: Yep. The trick with mosfet

author: katzohki
author_rank: Frequent Contributor
timestamp: February 12, 2015, 07:15:36 pm
content: "Ideal diode" is a concept, not an actual part you can go out and buy.

author: retrolefty
author_rank: Super Contributor
timestamp: February 12, 2015, 07:33:53 pm
content: Quote from: katzohki on February 12, 2015, 07:15:36 pmThe LTC4411 the user mentioned is marketed as a "LTC4411 - 2.6A Low LossIdeal Diodein ThinSOT"So at least LT thinks it's not just a concept?

author: c4757p
author_rank: Super Contributor
timestamp: February 12, 2015, 07:43:06 pm
content: Quote from: katzohki on February 12, 2015, 07:15:36 pm"Ideal diode" is a name for a specific sort of circuit...

author: mrkev
author_rank: Regular Contributor
timestamp: February 12, 2015, 07:50:01 pm
content: Quote from: c4757p on February 12, 2015, 07:43:06 pmI would say that it's both. A concept that can't be achieved (used when you learn about diodes in general, the reversed "L" shaped V-A char.), a protection circuit that is open with low RONwhen you apply voltage the correct way or circuit that uses transistors in rectifier to get rid of the voltage drop (and power looses) on normal diodes...

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: February 12, 2015, 10:19:38 pm
content: Quote from: katzohki on February 12, 2015, 07:15:36 pmBack diodes are as close as possible in a practical diode.

author: katzohki
author_rank: Frequent Contributor
timestamp: February 12, 2015, 10:27:33 pm
content: I see that they do call it that. That would be a little bit of "marketing gimmick" as the Vfwd is typ 17mV. That is very impressive, but I think it's a little silly to call it "ideal."

author: rx8pilot
author_rank: Super Contributor
timestamp: February 12, 2015, 10:32:54 pm
content: Quote from: mrkev on February 12, 2015, 07:50:01 pmThat is true, the Linear part is integrated in a single package which is convenient. For bigger current, you need separate controller and FET and maybe a few passives.