Yes, as a standard action you can total defense. Page 186 CRB, in the actions in combat section of chapter 8, looking at standard actions.
If you have 3 ranks in acrobatics it is a +6 dodge bonus to AC, +4 without 3 ranks. As a side note, this also extends to CMD. Fighting defensively has a -4 to attacks with a +2 to AC, +3 with 3 or more ranks in acro. Page 184 CRB, under chapter 8 in the attack section near the end of it.