Considerations for switch mode power supply with microcontroller and sensors
Many IC suppliers, TI amongst them, produce Evaluation boards for their chips. That's the case for the LM45602, too, and it's usually a good idea to use these to inspire your own design.

What's more important: the datasheets usually come with "demo" schematics. In this case, there's three of them on p. 24; chose the one you need:


V_out >= 3.3V 
V_out &lt; 3.3V 
and an "all the bells and whistles" circuit 


Chapter 9 goes into great detail about what components to chose for this circuit.

Also, the extensive "Detailed design routine" explains how you chose switching frequency etc. Usually, you try to go as high as feasible, to be able to filter out the noise with a simple low pass filter (as built by source impedance and the capacitors from V_out to ground), but if your ADC sampling rate happens to be close to that, you might actually want to chose something else. But that would be pretty advanced design.

Now, a switch mode power supply can, with reasonable effort, only ensure some limits on noise/ripple on the power line. Luckily, there's a lot of measurement data in the datasheet, too. For example, the step response oscilloscope measurement for the 5V output case of the first circuit:



It's up to you whether the noise in the figure is tolerable. 

What is often done in applications which measure or generate sensitive analog signals:

Use a switch mode power supply to generate a voltage slightly above the needed one, and then use a linear (often, low drop) voltage regulator to get the final voltage. That can easily eliminate a lot of the switching noise, and you often get a better accuracy by using decent-quality linear regulators cheaper.