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
Rev 3/30/06
SP6133 Evaluation Manual
Page 7 of 10
Copyright 2006 Sipex Corporation