I suspect my D24V6ALV is broken

Hi all.
I Just got a Pololu D24V6ALV Ste-Down Regulator (from a local source that sells Pololu items) but something seems wrong.
I haven’t done anything with it except soldered the header pins in place but when I set it up on my breadboard to adjust the output voltage I noticed something bad.
I have a power supply which I set to about 24V and connected to VIN and GND. That power supply has a built in current limiter and as a routine I set this to zero amps to begin with. SHDN was not connected and between VOUT and GND I had a volt meter.

As soon as I turned up the current limiter I understood that something was wrong because the limit was constantly met (I kept it below 500mA) as if something was shorted.
So i had another look at my connections and my soldering of the header, mistakes can be made, but found nothing bad. So then I started to measure the resistance between the pins on the regulator.
GND->VOUT = Nothing
GND->SHDN = 8.4 ohm
and now for the really strange one
GND->VIN = 1.1 ohm

I know it sounds like a soldering issue but I really can’t see anything bad with it so before I risk making any damage to the board trying to remove the header I would like to know it is supposed to behave.

Could someone please measure at a working one and tell me what it should be of if anyone have any experience on what symptoms one could expect from a faulty unit?


Hello, Peter.

I’m sorry to hear you are having trouble with the regulator. It definitely sounds like it is broken. Starting it at 24 V probably caused an LC spike that easily could have more than doubled the input voltage, exceeding the absolute maximum that the regulator chip can handle. We have a section of the product page for the D24V6ALV that warns about this and gives advice on how to prevent it.

- Ryan

Hi Ryan,
I read that part about spikes about 30 seconds to late I guess…
I’ll just have to get another one and this time compensate for the possible spikes BEFORE connecting.

Thanks anyway…
- Peter