Primary-Side PWM Power Switch
LD7921
02/02/2012
Primary-Side PWM Power Switch with CV/CC Operation
Ver. 00
General Description
The LD7921 integrated ...
Description
LD7921
02/02/2012
Primary-Side PWM Power Switch with CV/CC Operation
Ver. 00
General Description
The LD7921 integrated a 700V power MOSFET and a primary-side feedback PWM controller with CV/CC operation in a SOP-6/DIP-7 package. The LD7921 is designed for low power adapter/charger and LED lighting applications. It minimizes the components counts and is available in tiny packages. Those make it an ideal design for low cost applications. The LD7921 provides constant voltage, constant current (CV/CC) operation requiring neither photo-coupler nor secondary control circuit. Also, the LD7921 features OTP (Over Temperature Protection) and OVP (Over Voltage Protection) to prevent the circuit from being damaged under abnormal conditions.
Features
z Built-in 700V Power MOSFET z Primary-side Feedback Control z Constant Current Control z Built-in Load Regulation Compensation z Built-in Primary Winding Inductance Compensation z Low Startup Current (<16μA) z Current Mode Control with Cycle-by-Cycle Current
Limit z Green Mode Control z UVLO (Under Voltage Lockout) z LEB (Leading-Edge Blanking) on CS Pin z OVP (Over Voltage Protection) on Vcc z OTP (Over Temperature Protection)
Applications
z AC-DC Adapter and Charger z AC-DC LED Lighting
Typical Application
Leadtrend Technology Corporation
LD7921-DS-00 February 2012
1
www.leadtrend.com.tw
Pin Configuration
SOP-6 (TOP VIEW)
DIP-7 (TOP VIEW)
LD7921
VCC DRAIN VCC DRAIN DRAIN
85
TOP MARK YYWWPP
1 234
8 65
TOP MARK YYWWPP
1 234
YY: W...
Similar Datasheet