其具体的规格如下：

MP4021GS-A,30W以下隔离方案，全电压输入，电流波动1.5%以内, 260V时PF为0.95，效率在80%以上！

MPS4020/21 优势在于：

1.集成PFC,功率因数很高，大部分情况下在93%以上，最高可达98%

2.源边控制，省去光耦和相关电路，降低BOM cost

3.独特的MOSFET控制技术，对MOSFET和快恢复二极管的要求降低很多，对少的方案必须选择昂贵的MOSFET和二极管，进一步降低BOM COST

4.支持传统的调光模式（原因是采用了独特的MOSFET控制技术）。

总结: 隔离电源方案，效率85%、全电压输入，260V时PFC0.95、精度1.5%以内。MP4021是专门一颗针对LED驱动的芯片，功能全很多。单是PFC已经是很大的优势，客户会很看重这点，以及第二点的输出过压检测（就是可以做开路保护）。

Description:

The MP4021 is a primary-side-control offline LED lighting controller that achieves high power factor and accurate LED current for single-power stage, isolated lighting applications. The proprietary real current control method accurately controls the LED current from the primary side , and therefore significantly simplifies the LED lighting system design by eliminating the secondary side feedback components and the optocoupler.

The MP4021 integrates power factor correction and works in boundary conduction mode to reduce the MOSFET switching losses.

The extremely low start-up current and quiescent current reduces the total power consumption to provide a high efficiency solution for lighting applications.
The multi-protection features of MP4021 significantly improves greatly enhance the system reliability and safety. The MP4021 features over-voltage protection, short-circuit protection, cycle-by-cycle current limit, VCC UVLO and auto-restart over-temperature protection.

Features

• Real Current Control Without Secondary-feedback Circuit
• Unique Architecture for Superior Line Regulation
• High Power Factor: ≥0.9 Over Universal Input Voltage
• Boundary Conduction Mode Improves Efficiency
• Ultra-low (10µA) Start Up Current
• Low (1mA) Quiescent Current
• Input UVLO
• Cycle-by-cycle Current Limit
• Over-voltage Protection
• Short-circuit Protection
• Over-temperature Protection
• Available in an SOIC8 Package