SP6138_06 Datasheet, PDF (7/9 Pages) Sipex Corporation – Evaluation Board Manual

Step by step design procedures:
a. R2 = 21.8Ω
b. CZ3 = 85pF
c. Let fcrsover=200KHz then:
d. RZ2 = 60.3kΩ
e. CZ2 = 96pF
f. CP1 = 1.1pF
g. RZ3 = 0.75KΩ
h. CF1 = 18pF to stabilize SP6138ER1 internal Error Amplify
The above component values were used as a starting point for compensating the
converter and after laboratory testing the values shown in the circuit schematic of page
1 were used for optimum operation.
Figure 12- Gain/Phase measurement of SP6138EB shown on page 1, cross-over
frequency (fc) is just above 200KHz with a corresponding phase of 45 degrees
Aug 24-06
SP6138 Evaluation Manual
Page 7 of 9
©2006 Sipex Corporation