Used for: Stepping a voltage up or down ie lower or higher than the input with the same polarity
Pros:
- Steps input up to any value or down towards zero
- Simple circuit
- Easy Low-side gate drive for main switch 
 
- Inherently short circuit proof becasue of series capacitor
 
Cons:
- High output ripple -can be > output DC current so need large low ESR output caps 
- Requires two inductors
- Requires high quality series capacitor
- Complex to stabilise

