器件名称: DI-80
功能描述: 0.6 W Non-Isolated Utility Meter Power Supply
文件大小: 300.98KB 共2页
简 介:Design Idea DI-80 LinkSwitch-TN 0.6 W Non-Isolated
Utility Meter Power Supply
Application Utility Meter Device LNK302 Power Output 0.6 W Input Voltage 85-265 VAC, 47-63 Hz Output Voltage 12 V, 50 mA Topology Buck
Design Highlights
Universal AC input voltage range Meets EN62053-21:2003 (<1 W real and <5 VA apparent input power at 265 VAC) Long holdup time (140/580 ms at 115/230 VAC) High efciency (>60 % at 265 VAC) Very low no-load consumption (0.15 W at 265 VAC) EMI compliant (EN55022B, CISPR-22B) Extended line surge withstand with integrated 700 V MOSFET Small size and light weight Scalable output power using larger LinkSwitch-TN family members
In meter applications, capacitors C1 and C2 are sized for the required holdup time to write the meter reading to non-volatile memory after a power outage. LinkSwitch-TN uses on/off control to regulate the output voltage. When the current into the FEEDBACK (FB) pin exceeds 49 A, MOSFET switching is disabled for the next switching cycle. The 49 A threshold is specied at an FB pin voltage of 1.65 V (±7% over the entire operating temperature range), allowing it to be used as a reference. The power processing stage is formed by the LinkSwitch-TN, freewheeling diode D3, output choke L1, and the output capacitor C5. To a rst order, the forward voltage drops of D3 and D4 are equal. Therefore, the voltage across C4 tracks the output voltage. The voltage across C4 is sensed and regulated via the resistor divider R4 and R3 connected ……
