shimniok
Member
Thanks in advance for taking the time. I appreciate it.
A little background -- For various projects I seem to always rely on a 9V or some AA's and a 7805. Thing is, the 7805 isn't terribly efficient (4mA quiescent draw for the ones I stocked up on) and so I started doing some research into LDO regulators and step up DC-DC converters for use with battery operated projects. I'm interested most in the switched dc-dc converter/regulator chips.
But I'm awash in all the options. I could stare at data sheets for a long time... but...
Do you have any favorites that you find flexible enough to use for a variety of projects (like the 317 or 78xx that seem to come up all the time) ?
I'd like to find something that, in order of priority,
On the current... I could probably engineer around that in some cases. Like with this IR extender/repeater I am working on... I *could* run the 100mA LED(s) straight off the battery with a constant current source. So, if there's a regulator that otherwise fits but has only 50-100mA capacity, I can probably live with that.
What I've found so far...
Pololu uses a National NCP1402 on their LV168 board (which I have) and they sell a stand-alone regulator for $8 using this chip. It uses only 3 components outside of the chip (two caps and an inductor). So that's an option but it is a bit inefficient, I think, at only 84%.
Linear Tech. has a whole list... the one I settled on was perfect. Able to supply 400mA, 3 supporting components, 5V or 3.3V or 3V versions. Then I found out it isn't available anymore! They list others but don't know which are still avail. e.g., LTC3528, LTC3400, LTC3428, an so on and so forth. Loads of 'em. All > 90% efficient.
Used the National site to try and find some stuff. Was looking at the National LM27313, and LM2578A, but each requires a lot of supporting components. The 27313 is 90% efficient, and cheap at $.60 The 2578A is not so cheap at $1.42.
I've looked on Mouser to see what is there... but trying to filter down to a useful, short list has proven tough.
So hoping you have a few 'favorites' to help me focus my search a little better... thanks in advance!
Michael
A little background -- For various projects I seem to always rely on a 9V or some AA's and a 7805. Thing is, the 7805 isn't terribly efficient (4mA quiescent draw for the ones I stocked up on) and so I started doing some research into LDO regulators and step up DC-DC converters for use with battery operated projects. I'm interested most in the switched dc-dc converter/regulator chips.
But I'm awash in all the options. I could stare at data sheets for a long time... but...
Do you have any favorites that you find flexible enough to use for a variety of projects (like the 317 or 78xx that seem to come up all the time) ?
I'd like to find something that, in order of priority,
- has quiescent current ≤ 1mA.
- Run off two AA's (say, ~2.5V minimum or so)
- If it can run off a single AA, that'd be even better
- don't care if it's big TO-220 or microscope SC70.
- I don't care if it is smt or thru hole,
- Low supporting part count
- 5V -- can be adjustable or fixed
- Cheap is better, like $1 or less.
- I think it'd be most flexible if it can source 200-500mA
On the current... I could probably engineer around that in some cases. Like with this IR extender/repeater I am working on... I *could* run the 100mA LED(s) straight off the battery with a constant current source. So, if there's a regulator that otherwise fits but has only 50-100mA capacity, I can probably live with that.
What I've found so far...
Pololu uses a National NCP1402 on their LV168 board (which I have) and they sell a stand-alone regulator for $8 using this chip. It uses only 3 components outside of the chip (two caps and an inductor). So that's an option but it is a bit inefficient, I think, at only 84%.
Linear Tech. has a whole list... the one I settled on was perfect. Able to supply 400mA, 3 supporting components, 5V or 3.3V or 3V versions. Then I found out it isn't available anymore! They list others but don't know which are still avail. e.g., LTC3528, LTC3400, LTC3428, an so on and so forth. Loads of 'em. All > 90% efficient.
Used the National site to try and find some stuff. Was looking at the National LM27313, and LM2578A, but each requires a lot of supporting components. The 27313 is 90% efficient, and cheap at $.60 The 2578A is not so cheap at $1.42.
I've looked on Mouser to see what is there... but trying to filter down to a useful, short list has proven tough.
So hoping you have a few 'favorites' to help me focus my search a little better... thanks in advance!
Michael