Camera look with acceleration [Vector2.ClampMagnitude lags]

Hi all, I want to make camera look script for my scene. Camera is child of GO in scene, and I want to rotate this GO via accelerometer in X, Y axes, with circle clamp.

Here is what I’m using so far, its seems to work, but object rotates jerky

using UnityEngine;
using System.Collections;

public class Rotate : MonoBehaviour {


	public float cameraMovementSpeed = 5;
	public float Radius = 5;
	Vector2 rotation;

	void Update() {
		rotation = new Vector2(-Input.acceleration.y * cameraMovementSpeed, Input.acceleration.x * cameraMovementSpeed);
		Vector2 clampPos = Vector2.ClampMagnitude(rotation, Radius);
		transform.rotation = Quaternion.Euler(clampPos.x, clampPos.y, 0.0f);
	}
}

Have you tried moving it to fixedupdate or adding a multiplier time delta time?