OB2368

GENERAL DESCRIPTION

OB2368 is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications.

At full loading, the IC operates in fixed frequency (65KHz) mode. When the loading goes low, it operates in Green mode. When the load is very small, the IC operates in ‘Extended Burst Mode’ to minimize the standby power loss. As a result, high conversion efficiency can be achieved in the whole loading range.

VCC low startup current and low operating current contribute to a reliable power on startup and low standby design with OB2368.

OB2368 offers comprehensive protection coverage including VCC under voltage lockout (UVLO), external over temperature protection (OTP), output under voltage protection (UVP). and over voltage protection (OVP).  Excellent EMI performance is achieved with On-Bright proprietary frequency shuffling technique.

The tone energy at below 23KHz is minimized in the design and audio noise is eliminated during operation.

OB2368 is offered in SOT23-6 package.

APPLICATIONS

Offline AC/DC flyback converter for

■   General power supply

■   Power Adapter

FEATURES

■   Power on soft start reducing MOSFET Vds stress

■   Multi-Mode Operation

65KHz fix  frequency mode @ Full Load

Green mode@ Middle Load

  Burst Mode @ Light Load & No Load

■   Frequency shuffling for EMI

■   Extended burst mode control for improved efficiency and low standby power design

■   Audio noise free operation

■   Comprehensive protection coverage

o    VCC Under Voltage Lockout with hysteresis (UVLO)   

o    VCC Over Voltage Protection (VCC OVP)  

o    Output Over Voltage Protection(Output OVP) with auto-recovery, and  the OVP triggered voltage can be adjusted by the resistors connected between auxiliary winding and ground

o    Output Under Voltage Protection(Output UVP) with auto-recovery, and  the UVP triggered voltage can be adjusted by the resistors connected between auxiliary winding and ground

o    DEM open  protection, trigger  Output OVP

o    Adjust Over Temperature Protection(OTP) through CS pin with auto-recovery

o    Output diode short protection with auto-recovery

TYPICAL APPLICATION