MP4001

– UNIVERSAL INPUT HIGH BRIGHTNESS WLED DRIVER

MP4001 Rev. 1.02

www.MonolithicPower.com

13

5/1/2018

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© 2018 MPS. All Rights Reserved.

DESIGN EXAMPLE

The

design

example

introduces

a

typical

application of non-isolated LED lighting base on

MP4001. Figure 6 shows the schematic of this

application.

Figure 6: Schematic

Specification:

Input Voltage: Universal Input (90-265VAC)

LED Voltage: 10-30V

LED Current: 350mA

Passive PFC Circuit

To improve the Power Factor of this circuit, the

valley fill circuit is employed.

The following figures show the operation process

of Valley Fill Circuit.

Stage A: The AC line voltage rises from Va to

twice of Va, the circuit is powered by AC line

+

+

CX1

Fuse

LX1

LX2

CX2

C4

C3

R6

D4

D6

D5

Figure 7: Stage A of Valley Fill Circuit

C3and C4 is charged up by AC line, the circuit is

powered by AC line.

+

+

CX1

Fuse

LX1

LX2

CX2

C4

C3

R6

D5

D6

D4

Figure 8: Stage B of Valley Fill Circuit

Stage C: The AC line voltage drops from peak

peak voltage, the circuit is powered by AC line.

+

+

CX1

Fuse

LX1

LX2

CX2

C4

C3

R6

D4

D6

D5

Figure 9: Stage C of Valley Fill Circuit

Stage D: The AC line voltage drops from half of

AC line peak voltage to the minimum value of

power the circuit.

+

+

CX1

Fuse

LX1

LX2

CX2

C4

C3

R6

D4

D5

D6

Figure 10: Stage D of Valley Fill Circuit