WS9441P Datasheet, PDF (7/9 Pages) List of Unclassifed Manufacturers – Non-isolated BuckOffline LED Driver

WS9441P Product Description
And then the Rovp resistor value can be calculated by
the equation:
Rovp  120  7 .67 * Tovp * 10 ⁶ （KΩ）
It is suggested that the open circuit protection voltage is
set at or above 1.5 times maximum load voltage.
Protection Function
The WS9441P offers rich protection functions to
improve the system reliability, including LED open/short
protection, CS resistor short protection, VCC under voltage
protection, thermal regulation. When the LED is open circuit,
the system will trigger the over voltage protection and stop
switching. When the LED short circuit is detected, the system
works at low frequency and the CS pin turnoff threshold is
reduced. So the system power consumption is very low. At
some abnormal fault condition, such as CS resistor shorted
or inductor saturation, the internal fast fault detection circuit
will be triggered, the system stops switching immediately.
After the system enters into faulty condition, the VCC
voltage will decrease until it reaches the UVLO threshold,
then the system will restart again. If the fault condition is
removed, the system will recover to normal operation.
PCB Layout
The following rules should be followed in WS9441P PCB
layout:
VCC Capacitor: The VCC capacitor should be as close
as possible to the VCC Pin and GND pin.
Ground Path: The power ground path for current sense
resistor should be short, and the power ground path should be
separated from small signal ground path before connecting to
the negative node of the bulk capacitor.
The Area of Power Loop: The area of main current loop
should be as small as possible to reduce EMI radiation. And it
should be away from diodes and other heating components.
ROVP PIN: The ROVP resistor should be as close as
possible to the ROVP Pin to increase its resistance to prevent
from the interference.
DRAIN PIN: The copper area of DRAIN pin can be
increased for better thermal dissipation. And it should be away
from CS/VCC and ROVP Pin.
Line Voltage Compensation
The WS9441P integrates line voltage compensation
function, which makes LED current remain unchanged in the
range of full voltage with good line regulation and current
accuracy.
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS