Rev 3/30/06

SP6133 Evaluation Manual

Copyright 2006 Sipex Corporation

Page 7 of 10

Step by step design procedures:

a.

R2 = 21.8Ω

b.

CZ3 = 487pF

c.

Let fc =40KHz then:

d.

RZ2 = 32.9kΩ

e.

CZ2 = 1390pF

f.

CP1 = 22pF

g.

RZ3 = 1.09KΩ

h.

CF1 = 22pF to stabilize SP6138ER1 internal Error Amplifier

The above component values were used as a starting point for compensating the

converter and after laboratory testing the values shown in circuit schematic of page 1

were used for optimum operation.

Figure 12- Gain/Phase measurement of SP6133EB shown on page 1, cross-over

frequency (fc) is 60KHz with a corresponding phase of 50 degrees