|
|
PDF SW7230 Data sheet ( Hoja de datos )
| Número de pieza | SW7230 | |
| Descripción | Adaptive 100/120Hz Current Ripple Remover | |
| Fabricantes | SEMIPOWER | |
| Logotipo |  |
|
Hay una vista previa y un enlace de descarga de SW7230 (archivo pdf) en la parte inferior de esta página. Total 10 Páginas | ||
|
No Preview Available !
SW7230
Adaptive 100/120Hz Current Ripple Remover
Max Input Current ≤1A
Parameters Subject to Change Without Notice
FEATURES
Adaptive 100/120Hz current ripple remover
Input voltage range 5V~60V
Built-in 60V power MOSFET
LED voltage low to 0.4V when LED current is
1.3A
Programmable amplitude of LED current
ripple
Programmable maximum cathode voltage of
LED
Internal LED current limitation
Short protection
Hot plug protection
Over temperature protection
TO252-5L Package
APPLICATIONS
LED lightning
DESCRIPTION
SW7230 is used to drive a LED string (<60V), and
remove the 100/120Hz current ripple on AC/DC
power by a capacitor between VC and GND.
By sensing the LED pin voltage via a resistor
divider, SW7230 allows user to setup the
maximum cathode voltage of LED string.
SW7230 provides voltage limit threshold and
short threshold for protection. If the voltage on
LED pin exceeds limit threshold, the current ripple
removing function is blocked, which could help
limit the power dissipation on the chip. It’s
considered that LED is shorted when LED voltage
is higher than short threshold and remains over
0.5 second. The internal MOSFET shuts down
when LED is shorted.
SW7230 also provides OPEN and HOT-PLUG
protection.The maximum LED current is internally
limited at 1.3A.SW7230 provides over thermal
protection. When OTP is trigged, the current
removing function is blocked, and then the
temperature decreases.
TYPICAL APPLICATION
www.semipower.com.cn
1
1 page  
SW7230 Adaptive 100/120Hz Current Ripple Remover (Max 1A)
FUNCTIONAL DESCRIPTION
SW7230 is designed for driving one LED string
(≤50V) and removing the 100/120Hz LED current
ripple.
Theory of Operation
The LED string and SW7230 are both supplied by
an AC/DC current source. The LED pin is
connected to the cathode of LED string. SW7230
transfers the LED current ripple to voltage ripple
on chip, and ensures the constant voltage across
LED string and the current flow through LED
string.
The scalable adaptive function of SW7230 can
regulate the cathode voltage of LED string to
minimum to improve the efficiency of the system.
Current Ripple Removing
The capacitor CC between VC and GND is a
integration capacitor. SW7230 transform the
voltage on CC to a reference voltage. The current
regulator regulates LED current via negative
feedback control.
The relationship between the voltage on CC and
LED current is shown as following:
ILED = VVC * 800 (mA)
CC should be large enough in order to remove the
current ripple of the LED string. However, too
large capacitor may slow down the dynamic
response.
linear region, LED current regulation loop is open.
SW7230 detects it and discharges CC to reduce
the VVC and ILED, then the output voltage of power
supply is raised, and the LED current regulation
loop is close.
ILED
Linear Region
Regulator Open Loop
Discharge CC
Saturation Region
Regulator Close Loop
Charge CC
Regulated LED Pin voltage
VLED
LED Pin Voltage Limit
The voltage ripple on LED pin is very large when
the current ripple is removed, which would bring
large power dissipation on chip. The resistor
divider connected between LED and GND can
setup the limit value of LED Pin voltage.
Adaptive Regulation
SW7230 control the voltage on CC by monitoring
the operation state of built-in NMOSFET. The
efficiency of system is relatively low when
NMOSFET is working in the saturation region.
SW7230 detects it and charges CC to raise the
VVC and ILED, then the output voltage of power
supply is reduced, and the voltage drop on
NMOSFET decreases.
Conversely, when NMOSFET is working in the
The limit threshold is calculated as below:
Vlimit= 1V * (RLMT1+RLMT2)/RLMT2
LED Current Limit
The current of LED is limited at 1.3A internally.
The current limitation can protect the chip when
LED is short connected or HOT-PLUG.
www.semipower.com.cn
5
5 Page | ||
| Páginas | Total 10 Páginas | |
| PDF Descargar | [ Datasheet SW7230.PDF ] | |
Hoja de datos destacado
| Número de pieza | Descripción | Fabricantes |
| SW7230 | Adaptive 100/120Hz Current Ripple Remover | SEMIPOWER |
| 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 |