OB2004A数据手册OB中文资料规格书

描述 Description

OB2004A is a high performance and highly integrated secondary side synchronous rectification controller used for secondary side rectification in switch mode power supply system.It drivers a much lower voltage drop N-channel MOSFET to emulate the traditional diode rectifier at the secondary side of flyback converter, which can reduce heat dissipation, increases output current capability and efficiency, and simplify thermal design. It can support wide range of system output voltage 5V~12V.\r
It is suitable for multiple mode applicationsincluding discontinuous conduction mode(DCM), quasi-resonant mode (QR) and continuous conduction mode(CCM). Specially for CCM, to guarantee system reliability, innovative property prediction algorithm is used in SR turn-off control.In addition, to balance reliability and efficiency, OB2004A generates a driving signal with optimized dead time with respect to the primary side PWM signal from the information on the secondary side of the isolation transformer with the help of innovative property dead time control algorithm.\r
The externally adjustable minimum on time and innovative property off time control effectively avoid the ring impact induced by parasiticelements so that a reliable and noise free operation of the SR system is insured.C OB2004A is offered in SOT23-6 package.

特性 Features

• Secondary-side synchronous rectification controller for 5V~12V output system\r
• Up to 85V VD pin high voltage tolerance\r
• Externally adjustable minimum on time\r
• Suitable for DCM,QR and CCM operation\r
• Prediction algorithm for CCM\r
• Accurate secondary side MOSFET Vds sensing\r
• SR turn on/off dead-time control for high efficiency and low thermal with immunity of interference Adaptive off time control effectively avoid the ring impact induced by parasitic elements\r
• 3A/2A peak current sink/source driver capability\r
• VDD UVLO protection

应用 Application

• AC/DC 5V~12V adaptors\r
• Low voltage rectification circuits