STLD20D_06 datasheet(18/31 Pages) STMICROELECTRONICS

Nome de Peças	STLD20D

Descrição Electrónicos	White LED power supply

PDF	31 Pages

Scroll/Zoom	100%

Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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18 / 31 page

Components selection

STLD20D

18/31

In fact, in boost backlighting converter, the conduction losses (Pcond) lead by the forward

characteristics can be negligible compared to the losses induced by the reverse current

(Prev), especially at high temperature.

7.4

RLED feedback resistance selection

The average output current is regulated by sensing a low external ohmic sensing resistor

RLED. Thus, a constant current value is fixed for each LED whatever the ambient

temperature conditions. RLED is given by:

7.5

Efficiency

Efficiency is a significant parameter for the application. The higher the efficiency, the longer

the life time of the battery. The efficiency is given by:

LED

-----------

0.3V

20mA

----------------

Ω

[]

Efficiency

output

input

-------------------

LED

⋅

input

⋅

--------------------------------------------

[]

STLD20D Folha de dados(PDF) 18 Page - STMicroelectronics