Rev. 1.00

�0

���i� ��� �011

Rev. 1.00

�1

���i� ��� �011

HT7L4091

Universal Step-Down PWM Control

For High Brightness LED Lighting Control

Other Application Circuit

No Input Bulk Capacitor Circuit

L

D1

MOSFET

CS

GND

RT

LD

C7

Rcs

�C

EMI

Lc

Lc

Ca1

Ca�

0.1uF

0.1uF

400V

Essentia� com�onents

Used optional components

Unused optional components

Ra

Rb

1uF/50V

5�F

The application circuit is a low cost implementation which can improve the PF used within the

signal input voltage range.

The auxiliary winding application circuit can be chosen when used for a universal input voltage. If

frequency jittering is considered to reduce EMI effects, an optional 5pF capacitor may be added for

stabilisation purposes. Refer to the application notes for more details.

For more details refer to the application note.

High Efficiency Circuit

T�

D1

Rs

MOSFET

CS

GND

RT

LD

C7

Rg

Rsb

Dg

Rc

Cc

Ra

Da

�C

EMI

Lc

Lc

Ca1

Ca�

C1

0.1uF

400V

��uF

400V

Essentia� com�onents

Used optional components

Unused optional components

1uF/50V

Zin

5�F

The application circuit uses the auxiliary inductor to supply the device power to obtain better

efficiency.

If frequency jittering is used to reduce EMI interference effects, an optional 5pF capacitor may be

used for stabilisation purposes. For more details, refer to the application note for auxiliary inductor

applications.

For more details refert to the application note.