On 03/30/2017 09:07 PM, Tony Duell via cctalk wrote:
> The fundamental rule is 'You can't change the voltage across a > capacitor instantly'. There is a related one 'You can't change the > current through an inductor instantly'. It (of course) doesn't matter > if said capacitor or inductor is an actual component or 'strays'. Funny that driving DRAMs would be mentioned today. Yesterday, I was going through some of my old tubes of ICs and ran across some AM2966 DIPs. I didn't remember why I'd gotten them or even what they were. A glance at a datasheet refreshed my memory--basically they're LS244 octal drivers intended for MOS memory address lines. They feature 25 ohm resistors in the collectors of both of the totem-pole output transistors. Each output is spec-ed to sink a minimum of 50 ma. It takes some muscle to drive a capacitive load. --Chuck