MIC4720 Micrel Semiconductor, MIC4720 Datasheet - Page 16

• Manufacturer Part Number: MIC4720
• Description: 2A Integrated Switch Buck Regulator
• Manufacturer: Micrel Semiconductor

By looking at the graph, phase margin can be affected to
a greater degree with higher output voltages.
The next bode plot shows the phase margin of a 1.8V
output at 2A without a feedforward capacitor.
Micrel, Inc.
May 2007
50
45
40
35
30
25
20
15
10
5
0
1
Obtainable using C
Max. Amount of Phase Boost
OUTPUT VOLTAGE (V)
2
Voltage
3
FF
V
vs. Output
REF
4
= 1V
5
16
As you can see the typical phase margin, using the
same resistor values as before without a feedforward
capacitor results in 33.6 degrees of phase margin. Our
prior measurement with a feedforward capacitor yielded
a phase margin of 47 degrees. The feedforward
capacitor has given us a phase boost of 13.4 degrees
(47 degrees- 33.6 Degrees = 13.4 Degrees).
M9999-051707
MIC4720