XRP7662 Datasheet, PDF (15/19 Pages) Exar Corporation – 12A 300KHz Synchronous Step Down Regulator

XRP7 66 2
Pow er Blox ^TM
1 2 A 3 0 0 KHz Sy n ch r on ou s St ep Dow n Reg u lat or
f_PLC 
1
2S LC
When the output capacitors are of a Ceramic
Type, the XRP7662 Evaluation Board requires
a Type III compensation circuit to give a
phase boost of 180° in or der to counteract the
effects of an under damped resonance of the
output filt er at the double pole frequency.
Fig. 22 : XRP7662 Voltage Mode Control Loop with Loop Dynamic
Fig. 23 : Bode Plot of Type III
Error Amplifier Compensation
RZ3 CZ3
CP1
CZ2
RZ2
VOUT
R1
68.1 k:
RSET =
54.48
(VOUT ±0.8)
k:
RSET
-
+
+
-
0.8V
Fig. 24 : Type III Error Amplifier
Compensation Circuit
© 2012 Exar Corporation
15 / 19
Rev. 2. 2.0