SP7606

12/17/07 rev: A

SP7600

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page

The compensation becomes much harder to

accomplish when due to the RHP zero as well

as the filter double pole. Unlike the DCM filter

the gain drops off sharply at the filter double

pole and does not recover. More over the

Right Half plane zero also adds another -90

degrees to the phase. Due to the RHP zero the

compensation network for a boost regulator

needs to roll off below the RHP zero location.

When compensating for CCM mode of

operation the user will need to add a phase

boost

capacitor

and

resistor

to

help

compensate for the filter double pole. The

location of the zero and poles for Type 3

compensation is.

-

+

5

6

7

RZ

CZ

CP

Vref

R1

Vout

Comp

CZ1

RZ1

 

Error Amplifier Type 3 Compensation

Frequency

Gain

Phase

0 dB

0 deg

-270 (deg)

Gain of Control to Output transfer CCM