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vikas
04-23-2011, 01:00 AM
Hi guys i need a small SMD comparator which is locally availbile , preferably SOT-23 to go with QRE1113. Any ideas ?

Single comparator per chip is whats more than enough, Need to build a Motor encoder :) , which needs to fit in a tight space.

The lower the cost the better . 0 - 5V is the working range.

allbits
04-23-2011, 05:41 AM
No idea with the qre package, I normally use the old 311 in the s08, or use the comparator in the controller. 7211 is available in sot, and if you want open drain, you can use 7221.

Microchip has some..
http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=11011&mid=11&lang=en&pageId=79

never used any of them..

But will a voltage detector be sufficient for you? Are you looking at zero crossing? What are you comparing the input with?

http://www.microchip.com/wwwproducts/Devices.aspx?dDocName=en010713
I dont know if this will fit in, but in case you have a fixed voltage to compare with, you have a smaller 3 pin SOT.

Dont think there are locally available, but since you already purchase from microchip direct, sourcing them should not be a problem.

vikas
04-23-2011, 07:29 AM
lm311 looks likea good idea , i will get a approximate PCB made and check if its upto the size. But SOIC 8 is much bigger than sot-23. Needs to be looked into.

Basically trying to make this ,

http://www.pololu.com/catalog/product/1217

for a custom application.

Coolpratheesh
04-24-2011, 07:45 PM
lm311 looks likea good idea , i will get a approximate PCB made and check if its upto the size. But SOIC 8 is much bigger than sot-23. Needs to be looked into.

Basically trying to make this ,

http://www.pololu.com/catalog/product/1217

for a custom application.
Vikas wat about the comparator that is used in the Pololu sensors.... are dey available.... they look like they could fit in ....