STMicroelectronics HVLED805 Evaluation Board EVALHVLED805 EVALHVLED805 Hoja De Datos

Doc ID 18077 Rev 1

19/29

Combining (2), (3) (5) and (6):

This formula shows that the average output current does not depend anymore on the input 
or the output voltage, neither on transformer inductance values. The external parameters 
defining the output current are the transformer ratio n and the sense resistor R

SENSE

.

SENSE

C

P

R

V

I

=

SENSE

CLED

OUT

R

V

2

n

I

⋅

=

From R sense

.

To PWM Logic

CLED

R dmg

D EMAG

LOGIC

S

R

Q

R

Rfb

Iref

Q1

Aux

+

-

CC

ILED

DMG