Datasheet

Application information HVLED805
24/29 Doc ID 18077 Rev 1
before the V
CC
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
t
t
t
VSOURC E
1 V
Two switching cycles
VCC
Vcsdis