深圳市广辉电子有限公司

The MC34262/MC33262 are active power factor controllers specifically designed for use as a preconverter in electronic ballast and in off-line power converter applications. These integrated circuits feature an internal startup timer for stand-alone applications, a one quadrant multiplier for near unity power factor, zero current detector to ensure critical conduction operation, transconductance error amplifier, quickstart circuit for enhanced startup, trimmed internal bandgap reference, current sensing comparator, and a totem pole output ideally suited for driving a power MOSFET.

Also included are protective features consisting of an overvoltage comparator to eliminate runaway output voltage due to load removal, input undervoltage lockout with hysteresis, cycle-by-cycle current limiting, multiplier output clamp that limits maximum peak switch current, an RS latch for single pulse metering, and a drive output high state clamp for MOSFET gate protection. These devices are available in dual-in-line and surface mount plastic packages.

代替SG3561和TDA4817 的功能

以功率因数控制芯片MC33262为,设计了一种宽电压输入范围、固定升压输出的150 W的AC/DC变换器.对该变换器用有源功率因数校正(APFC)技术、MC33262芯片的原理和结构做了详尽的分析和讨论.实验结果表明所设计的以MC33262为的有源功率因数校正器能在95～250 V的宽电压输入范围内得到非常稳定的400V直流电压输出,并使得功率因数达到0.99以上,总谐波畸变降低至6%.