Hello all,

I am after a wee bit of help.

I am looking for a regulator that is similar to a LP2953, but with a much higher output current, for a PSU for a 4-20ma sensor display.

My understanding is that the LP2953 can be configured to 'turn off' or rather snap off when the input voltage is too low to provide the correct output. See page 26 of below link http://sva.ti.com/assets/en/appnotes/f4.pdf

I would like to build a very simple DC (battery powered) PSU (12 - 18v, maybe 24v max input) 12v output @ minimum 800ma - prefer 1a or more.

The reason for having the PSU switch off when the voltage drops, is the sensor attached doesn't behave accurately when the PSU is too low. Rather than have a warning led, I'd prefer if it simply turned off.

Any ideas?

Thanks in advance.

 

So you need a low drop out regulator that can supply 800-1000mA and at the same time be able to shut down.

 

any of these of use?

http://www.onsemi.com/pub_link/Collateral/NCP59302-D.PDF

http://www.onsemi.com/PowerSolutions/parametrics.do

 

The LP2953 has an internal comparator that monitors VIN and signals when it's too low which can be used to shut the thing down. I developed that part at Nat Semi back in 1992. I don't know of any other similar parts higher current. FYI, that part was a poor seller for a variety of reasons so no higher current versions were ever done. There are a lot of higher current LDO regs available that have a shutdown pin so the same function (auto shut down) can be done for about ten cents using an external comparator.

http://www.ti.com/lit/ds/symlink/lp3961.pdf