MIC4681 Micrel Semiconductor, MIC4681 Datasheet - Page 9

• Manufacturer Part Number: MIC4681
• Description: 2A-Peak SuperSwitcher SOP-8 Buck Regulator
• Manufacturer: Micrel Semiconductor

Bode Plots
The following bode plots show that the MIC4681 is stable over all conditions using a 68 F inductor (L) and a 220 F output
capacitor (C
February 2001
MIC4681
V
V
I
Amb = 22 C
V
V
I
Amb = 22 C
OUT
V
V
I
Amb = 22 C
OUT
OUT
IN
OUT
OUT
IN
OUT
IN
OUT
= 30V
= 12V
= 7V
= 0A
= 0A
= 0A
= 5.0V
= 5.0V
= 5.0V
). To assure stability, it is a good practice to maintain a phase margin of greater than 35 .
Phase Margin = 102
Phase Margin = 118
Phase Margin = 94
No-Load Stability
No-Load Stability
No-Load Stability
L = 68 F
C
L = 68 F
C
L = 68 F
C
OUT
OUT
OUT
= 220 F
= 220 F
= 220 F
9
V
V
I
Amb = 22 C
V
V
I
Amb = 22 C
OUT
OUT
IN
OUT
IN
OUT
= 7V
= 12V
= 1.1A
= 1.4A
V
V
I
Amb = 22 C
OUT
= 5.0V
= 5.0V
IN
OUT
= 30V
= 1.1A
= 5.0V
Phase Margin = 74
Phase Margin = 53
Phase Margin = 59
Full-Load Stability
Full-Load Stability
Full-Load Stability
L = 68 F
C
L = 68 F
C
L = 68 F
C
OUT
OUT
OUT
= 220 F
= 220 F
= 220 F
MIC4681
Micrel