e5470 should use a standard Dell barrel charger.

Amazon has the genuine ones for $26. https://www.amazon.com/Dell-Laptop-Charger-Adapter-Latitude/dp/B07Q3YDR1C/

Do not buy a cheaper one that is not a Dell charger because, even though the wattage and connector type may be identical, the construction of said accessory is probably not.

I've seen some bad things happen to non-genuine adapters when they fail. I've also had some not power a laptop sufficiently and they'll run super slow and the battery won't charge.