STLD20D-DEF datasheet(18/31 Pages) STMICROELECTRONICS

Il numero della parte	STLD20D-DEF

Spiegazioni elettronici	White LED power supply

PDF	31 Pages

Scroll/Zoom	100%

Produttore elettronici	STMICROELECTRONICS [STMicroelectronics]

Homepage	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-DEF Scheda tecnica(PDF) 18 Page - STMicroelectronics