|
|
PDF WS9442 Data sheet ( Hoja de datos )
| Número de pieza | WS9442 | |
| Descripción | Non-isolated Buck Offline LED Driver | |
| Fabricantes | Winsemi | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de WS9442 (archivo pdf) en la parte inferior de esta página. Total 9 Páginas | ||
|
No Preview Available !
WS9442 Product Description
Features
Critical Conduction Mode Operation
Internal 500V Power MOSFET
Gate Drive and No Auxiliary Winding
±3% LED Current Accuracy
Efficiency up to 93%
LED Short Circuit Protection
LED Open Circuit Protection
Current Sense Resistor Short Protection
Thermal Regulation Function
Applications
LED Bulb Lights
LED Panel Lights
LED Strings
Typical Application Circuit
Non-isolated Buck Offline LED Driver
Description
The WS9442 is a high precision buck constant current
LED driver and is applied to non-isolated buck LED power
system with AC input voltage of 85VAC-265VAC. The
WS9442 integrates a 500V power MOSFET, and can
achieve excellent constant current performance with very
few external components, so the system cost and size are
minimized. The driver operates in critical conduction mode,
and the output current does not change with the inductance
and LED output voltage. The operating current of the IC is
200uA, so it doesn’t need the auxiliary winding for supplying
the chip, thus simplifying design and reducing cost.
The WS9442 adopts intelligent temperature control and
thoroughly solves the problem of light flashing at high
temperatures. The WS9442P offers full protection functions
to improve the system reliability, including LED open circuit
protection, LED short circuit protection, CS resistor short
circuit protection and thermal regulation function.
The WS9442 is available in DIP-7 Package.
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
Copyright@Winsemi Microelectronics Co., Ltd., All right reserved.
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
0318
1 page  
WS9442 Product Description
Function Description
The WS9442 is a high performance non-isolated buck
converter specially designed for LED lighting. The device
integrates a 500V power MOSFET. With the help of
advanced constant current control and gate drive technology,
the converter achieves excellent constant current
performance with very few external components. It does not
need auxiliary winding for powering the IC or voltage sensing,
hence the system size and cost is greatly reduced.
Start Up
After system powered on, the VCC pin capacitor is
charged up by the start up resistor. When the VCC pin
voltage reaches the turn on threshold, the internal circuits
start operating. The WS9442 integrates a 17V ZENER diode
to clamp the VCC voltage. Due to the ultra-low operating
current, the auxiliary winding is not needed to supply the IC.
The typical value of the start-up current is 200uA (the
maximum value is 300uA). For the application of 176VAC—
264VAC, the start-up resistor can be calculated by the
equation:
RST
VIN _ MIN 1.414
I ST _ MAX
176 1.414
300
820K
Two resistors in 1206 size SMD can be used in series.
comparator, and the voltage on CS pin is compared with the
internal 400mV reference voltage. The MOSFET will be
switched off when the voltage on CS pin reaches the threshold.
The CS comparator includes a 350ns leading edge blanking
time.
The peak inductor current is calculated by the equation:
I PK
400 (mA)
RCS
Where, RCS is the current sense resistor value.
The current in LED can be calculated by the equation:
I LED
I PK
2
(mA)
Where, IPK is the peak current of the inductor.
Freewheeling Diode
The diode will bear the reverse voltage equal to the input
voltage when the MOSFET is on. A 600V diode was
suggested to use. Besides, the operating frequency of
freewheeling diode is from 20K to 120 KHz, such ultra fast
recovery diodes as ES and ER whose Trr is less than 50ns are
good choice.
VCC Capacitor Selection
The Vcc capacitor is used to bypass noise to IC, so that
to assure its stable operation, and should be as close as
possible to the chip.
A 1uF capacitor can be used in Vcc. If selecting MLCC,
the material of X7R will be used to satisfy the stability of the
Input Electrolytic Capacitor
Input voltage should be considered in to the capacitor
pressure, and the common value is 400V.
In general, the capacity design can be calculated by the
following empirical equations:
90Vac~264Vac: 1W output uses1uF buck electrolytic
capacity under high temperatures. Due to external damage capacitor;
resulted from small volume and brittle texture of MLCC, the
176Vac~264Vac: 1W output uses 0.5uF buck electrolytic
Vcc is easy to leakage currents, which will make the WS9442 capacitor.
unable to start. Strict control measures are taken in its layout
and productive process.
Output Capacitor
Constant Current Control
Electrolytic capacitor is recommended to be used. Its
stable capacitance can improve the efficiency of power supply,
The WS9442 utilizes proprietary current control method. the LED ripple current and luminous efficiency.
It can achieve precise LED output current with a few external
Vovp voltage should be considered in output capacitor
components. Cycle by Cycle current sense is adopted in pressure.
WS9442, the CS pin is connected to the current sense
Inductor Selection
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
www.winsemi.com Tel : +86-755-8250 6288 Fax : +86-755-8250 6299
WINSEMI MICROELECTRONICS
WINSEMI MICROELECTRONICS
5/9
5 Page | ||
| Páginas | Total 9 Páginas | |
| PDF Descargar | [ Datasheet WS9442.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| WS9441 | Non-isolated Buck Offline LED Driver | Winsemi |
| WS9441P | Non-isolated Buck Offline LED Driver | Winsemi |
| WS9442 | Non-isolated Buck Offline LED Driver | Winsemi |
| WS9442P | Non-isolated Buck Offline LED Driver | Winsemi |
| Número de pieza | Descripción | Fabricantes |
| SLA6805M | High Voltage 3 phase Motor Driver IC. |
 Sanken |
| SDC1742 | 12- and 14-Bit Hybrid Synchro / Resolver-to-Digital Converters. |
 Analog Devices |
|
DataSheet.es es una pagina web que funciona como un repositorio de manuales o hoja de datos de muchos de los productos más populares, |
| DataSheet.es | 2020 | Privacy Policy | Contacto | Buscar |