HVLED805TR datasheet(24/29 Pages) STMICROELECTRONICS

Nome de Peças	HVLED805TR

Descrição Electrónicos	Off-line LED driver with primary-sensing

PDF	29 Pages

Scroll/Zoom	100%

Fabricante Electrônico	STMICROELECTRONICS [STMicroelectronics]

Página de início	http://www.st.com

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24 / 29 page

Application information

HVLED805

24/29

Doc ID 18077 Rev 1

before the VCC capacitor is charged again and the device restarted. Ultimately, this will

result in a low-frequency intermittent operation (Hiccup-mode operation), with very low

stress on the power circuit. This special condition is illustrated in the timing diagram of

Figure 18

5.10

Layout recommendations

A proper printed circuit board layout is essential for correct operation of any switch-mode

converter and this is true for the HVLED805 as well. Careful component placing, correct

traces routing, appropriate traces widths and compliance with isolation distances are the

major issues. In particular:

●

The compensation network should be connected as close as possible to the COMP

pin, maintaining the trace for the GND as short as possible

●

Signal ground should be routed separately from power ground, as well from the sense

resistor trace.

Figure 19.

Hiccup-mode OCP: timing diagram

VDS

VccON

VccOFF

Vccrest

Secondary diode is shorted here

VSOURCE

1 V

Two switching cycles

VCC

Vcsdis

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