IN-PLUG

© Copyright 2005-2007 - ASIC Advantage, Inc. – All rights reserved

- Revision 11 – April 02, 2007

13 / 18

40WATT APPLICATION SCHEMATIC: IPS401 White LED Driver Powering 3 rows of 125 x 100mW HB

LEDs (Vin = 100V/220V AC)

Fig. 13

The application shown in Fig. 13 is typical of large PDP or LCD panel backlighting control. The requirement is

perfectly suited for a boost converter topology, where the IPS401 brings the simplest, highest-efficiency, highest

power factor and cost-effective solution. The load, limited to 3 strings of 125 HB LEDs requires only to deliver 40W of

continuous power on a typical 400V DC/current regulated rail from a wide range mains. But the number of strings

could be easily extended by a factor of 10 as the IPS401 would efficiently deliver an output power up to 500W should

some components such as TR1 (inductor), Q1 (MOSFET), D6 (Output Diode) be sized accordingly.

The above function is available for demonstration in AAI’s IPS-DK401 demokit. Please contact sales

C3

0.22uF

450VAC

3

1

BR1

AC IN

Q1

NMOSFET

4N60

U2

IPS401

TR1

INDUCTOR WITH BIAS

D1

150V

D2

150V

D3

150V

R1

24K

C1

0.015uF

C4

4700pF

D5

LED

R2

1K

R3

100

R4

100

R5

820K

R6

750K

D6

Ultra Fast

FR804

D7

D8

2 x 1N4148

C5

47uF

16V

C6

1uF

D9

1N4148

D10

LED

D11

LED

D12

LED

D13

LED

D14

LED

D15

LED

D16

LED

D17

LED

D18

LED

D19

LED

D20

LED

D21

LED

D22

LED

D23

LED

D24

LED

D25

LED

D26

LED

R7

16

R8

16

R9

3 / 2W

R9

16

String

Current

Sensing

Dimming

Three Strings of 125 x100mWWhite LEDS

BOOST TOPOLOGY

C8

100pF

Input

100 / 220V AC

GND

R10

300k

C9

1uF

C2

100pF

Q2

ZTX549

C10

0.01uF

500V

R11

1M

D4

1N4148

R12

24k

R13

200

D28

Schottky

R14

200

D29

Schottky

R15

200

D30

Schottky

47uF

R16

10k

D32

1N4148