UC2852NG4

高功率因数前置稳压器 High Power-Factor Preregulator

High Power-Factor Preregulator

DESCRIPON

The UC1852 provides a low-cost solution to active power-factor correction PFC for systems that would otherwise draw high peak current pulses from AC power lines. This circuit implements zero-current switched boost conversion, producing sinusoidal input currents with a minimum of external components, while keeping peak current substantially below that of fully-discontinuous converters.

The UC1852 provides controlled switch on-time to regulate the output bulk DC voltage, an off-time defined by the boost inductor, and a zero-current sensing circuit to reactivate the switch cycle. Even though switching frequency varies with both load and instantaneous line voltage, it can be maintained within a reasonable range to minimize noise generation.

FEATURES

• Low-Cost Power Factor Correction

• Power Factor Greater Than 0.99

• Few External Parts Required

• Controlled On-Time Boost PWM

• Zero-Current Switching

• Limited Peak Current

• Min and Max Frequency Limits

• Starting Current Less Than 1mA

• High-Current FET Drive Output

• Under-Voltage Lockout