Switching Power Supplies A - Z

Chapter 7

This looks like a series combination (for resistors and inductors), but in reality, it is a

parallel combination (of capacitors). Similarly, two capacitors in series give us

Z(s) = Z

1

(s) + Z

2

(s) ⇒

1

Cs

=

1

C

1

s

+

1

C

2

s

C =

C

1

× C

2

C

1

+ C

2

(series capacitance)

This looks like a parallel combination (for resistors and inductors), but in reality, it is a series

combination (of capacitors).

To calculate the response of complex circuits and stimuli in the s-plane, we will need to use

the above impedance summing rules, along with the rather obvious s-plane versions of the

electrical laws. For example, Ohm’s law is now

V(s) = I(s) × Z(s)

Finally, the use of s gives ...