I'm running a servo from a 12V -> 5V buck regulator. The servo has a stall current of about 500mA and a nominal operating current of about 200mA. Here's a scope reading from when the servo starts moving:

(output side)

![enter image description here](https://i.stack.imgur.com/fKUpD.png)

(input side)

![enter image description here](https://i.stack.imgur.com/3gdlg.png)

The output voltage drops from 5.3V to 3.8V and then climbs back up, while the input voltage drops from 11.8 to about 10.2. The time scale is 20ms / div. I have a 250uA electrolytic cap near the servo power pin. Is this "ladder" normal? Or is something not right with my regulator? 

The reg is an [LM2734](http://www.ti.com/lit/ds/symlink/lm2734.pdf), which can do 1A, with a 4.7uH inductor with a 1.2A saturation point. The input is 8 AA Alkaline batteries.

Here's the servo circuit:

![enter image description here](https://i.stack.imgur.com/6rf59.png)

And here's the regulator:

![enter image description here](https://i.stack.imgur.com/NtACS.png)