MIC2208 MICREL [Micrel Semiconductor], MIC2208 Datasheet - Page 14

• Manufacturer Part Number: MIC2208
• Description: 3mmx3mm 1MHz 3A PWM Buck Regulator
• Manufacturer: MICREL [Micrel Semiconductor]

TYPE III compensation
Type III in our case, is a dominant pole (C3 and R1)
followed by a zero (C3 and R4) and an additional
zero (C5 and R4), allowing the final pole to be
provided by the output inductor and output capacitor.
This mode of compensation is required when using
low ESR output capacitors, such as ceramic
capacitors. The additional zero offsets the double
pole created by the inductor/output capacitor filter.
Bill of Materials
Item
C1a,C1b
C2
C3
C4
C5
D1
L1
R1
September 2005
-10
-20
80
70
60
50
40
30
20
10
100
Gain
Phase
Part Number
C2012JB0J106K
GRM219R60J106KE19
08056D106MAT
0402ZD104MAT
0402ZD103MAT
C3216X5R0J476K
GRM32ER60J476ME20 47uF Ceramic Capacitor X5R 1206 6.3V
12106D476MAT2A
VJ0402A330KXAA
SSA33L
RLF7030-1R0N6R4
744 778 9001
IHLP2525AH-01 1
CRCW04024992F
Type III Compensation
1k
Frequency (KHz)
10k
V
V
I
C
OUT
IN
OUT
OUT
100k
=5V
=3A
=1.0V
=47µF
IN
1M
288
252
216
180
144
108
72
36
0
-36
-72
10uF Ceramic Capacitor X5R 0805 6.3V
Description
10uF Ceramic Capacitor X5R 0805 6.3V
10uF Ceramic Capacitor X5R 0805 6.3V
0.1uF Ceramic Capacitor X5R 0402 10V
1nF Ceramic Capacitor X5R 0402 10V
47uF Ceramic Capacitor X5R 1206 6.3V
47uF Ceramic Capacitor X5R 1210 6.3V
33pF Ceramic Capacitor 0402
3A Schottky 30V SMA
1uH Inductor 8.8mOhm 7.1mm(L) x 6.8mm (W)x 3.2mm(H)
1uH Inductor 12mOhm 7.3mm(L)x7.3mm(W)x3.2mm(H)
1uH Inductor 17.5m Ω ( L)6.47mmx(W)6.86mmx(H) 1.8mm
49.9K Ω 1% 0402 resistor
14
MIC2208
Type III Open Loop Gain Response
Dominant
Pole
Zero
Frequency (Hz)
Zero
Manufacturer
TDK
AVX
AVX
AVX
TDK
Murata
AVX
Vishay VT
Vishay Semi
TDK
Wurth Electronik
Vishay Dale
Vishay Dale
Murata
Frequency
20dB/Decade
LC
www.micrel.com
M9999-092905
Qty
2
1
2
1
1
1
1
1