器件名称: DI-76
功能描述: 3.1 W Low Parts Count Power Supply
文件大小: 285.93KB 共2页
简 介:Design Idea DI-76 LinkSwitch
Application Appliance/Industrial Control Device LNK520P
3.1 W Low Parts Count Power Supply
Power Output 3.1 W Input Voltage 100-375 VDC Output Voltage 12 V Topology Flyback
Design Highlights
Replaces a linear transformer based power supply at the same or lower cost, but with much better performance High Efciency: >75% at >100 mA of load current Primary side regulated: requires no optocoupler <300 mW no-load power consumption at 375 VDC Very low parts count: only 9 components! 12 V output: ideal for driving motors, relays, or SCRs
restart (for hard short circuits) and thermal shutdown effectively produce a very rugged design. LinkSwitch derives all feedback information from the primary side, thus no optocoupler is required. During output diode (D4) conduction, the output voltage is reected through the transformer turns ratio, providing a primary feedback voltage (VOR), which is rectied by diode D3 and held by capacitor C4. Resistor R3 limits the effects of transformer leakage on the feedback voltage. Resistor R2 feeds the VOR signal as a current to the CONTROL pin of the LinkSwitch, controlling duty cycle (and primary current limit during overload conditions). When there is little or no feedback signal (such as a short circuit) the LinkSwitch goes into auto-restart, limiting output current to approximately 40 mA. Capacitor C3 provides device decoupling. The extra winding on pin 3 of T1 is a shield that reduces EMI.
Operation
The very low……
