Latitude D620 - Power Adapter Requirements

Hi,

I have a Latitude D620 that, according to the bottom of the laptop requires 19.5V and 4.62A.  The power adapter that came with it is a PA-12 19.5V and 3.34A, now when you turn on the laptop it says it can't detect the power adapter.  I thought I had ordered a power adapter that had the same power requirements listed on the laptop itself but the one I just got in the mail is the same PA-12 19.5V and 3.34A.  I plugged it in anyways and the laptop boots up just fine now with no errors.

Is this the correct power adapter or should I get one that matches what is listed on the laptop exactly?  I thought if I ran a power adapter with less amps, I could burn out the power adapter.... thanks."