next topic »

[on:]

http://datasheets.maxim-ic.com/en/ds/MAX1722-MAX1724.pdf
On the first page of this datasheet it gives the typical circuit, which is what I need to get 3.3 volts from two Arduino battery's.  What do I connect the SHDN pin to if I won't need the shutdown function.  It says,
 The MAX1723/MAX1724 feature an active-low shutdown that reduces quiescent supply current to 0.1μA.

And in a table it has, "shutdown input, drive High for normal operation.

...so do I connect it to the voltage in pin (batteries), or the output 3.3 volt pin.  I figure I might as well get it right now, before I make a pcb...
Thanks

[Reply #1 on:]

Read the next line in the spec "For normal operation, connect SHDN to the input."

Another hint is in the "Absolute max ratings" section where you can see that SHDN takes -.3 to +6V.  Since the nominal input voltage should be 5.5v, SHDN can certainly handle the input voltage level.

Cheers!
Andrew

[Reply #2 on:]

Aha, it's right there in black and white

[Reply #3 on:]

What about capacitors?  When using a 7805 to bring vOltage down, I use a 100 uF cap on the input and a 10 & .1 uF cap on the output. Should I use any of these?  Probably the .1 uF at least, and one of them next to each chip, but anythIng else around this regulator?