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ML4869
27µH
(SUMIDA CD75)
VIN
100µF
ML4869
VL1 PWR GND
VIN
NC
GND
VL2
SHDN VOUT
IOUT
100µF
Figure 1. Application Test Circuit
IL
1
VL1
VIN
2
RSENSE
START-UP
6
VL2
SHDN
SHUTDOWN
Q3
CONTROL
4
SYNCHRONOUS
RECTIFIER
CONTROL
Q2
A2
VOUT
5
VOUT
+
–
BOOST
A1 SHDN
CONTROL
Q1
PWR GND
8
A3
ISET
2.4V
GND
3
Figure 2. PFM Regulator Block Diagram
IL(MAX)
IL
ISET
0
VOUT
VL2
0
Q1 ON
Q2 OFF
Q1 OFF
Q2 ON
Figure 3. Inductor Current and Voltage Waveforms
4