OB2273C

GENERAL DESCRIPTION

OB2273C is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications.

PWM switching frequency at normal operation is internally fixed and is trimmed to tight range. At no load or light load condition, the IC operates in extended ‘burst mode’ to minimize switching loss. Lower standby power and higher conversion efficiency is thus achieved.

VCC low startup current and low operating current contribute to a reliable power on startup and low standby design with OB2273C.

OB2273C offers comprehensive protection coverage with auto-recovery including Cycle-by-Cycle current limiting (OCP), over load protection (OLP), VCC under voltage lockout (UVLO), over temperature protection (OTP), 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.

OB2273C is offered in SOT23-6 package.
 

FEATURES

   Level 6 compliance with<75mW standby power at universal AC input.

   Power on soft start reducing MOSFET Vds stress

   Frequency shuffling for EMI

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

   Audio noise free operation

   Forced pulse generation

   Fixed 65KHz (typical) switching frequency

   Comprehensive protection coverage

o    VCC Under Voltage Lockout with hysteresis (UVLO)   

o    VCC Over Voltage Protection (VCC OVP)  

o    Cycle-by-cycle over current threshold setting for constant output power limiting over universal input voltage range

o    Over Load Protection (OLP) with auto-recovery

o    Output diode short protection with auto-recovery


APPLICATIONS

Offline AC/DC flyback converter for

   General power supply

   Power Adapter
 
  

TYPICAL APPLICATION