Analysis and design of adapter met energy efficiency code under standby condition without using current sensor and hysteresis circuit for notebook computer applications

The main theme of this paper is to present the analysis and design of an adapter for notebook computer. The contributions of this paper include the analysis and design of circuits, including PFC-OFF control and auxiliary circuit which will significantly reduce the standby power consumption to meet the energy efficiency specifications under standby condition. Moreover, it will be shown that these circuits don't use any current sensor and hysteresis circuit to reduce the cost and avoid false activation caused by current noise. The specifications of adapter are as follow: universal input voltage: AC 90∼265 V, 50∼60Hz; output voltage: 19V/DC 100W; standby power (European and Japan Specifications): input power