OB2506 is a highly integrated current mode PFM/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.

VDD low startup current and low operating current contribute to a reliable power on startup and low standby design with OB2506.

OB2506 offers complete protection coverage with auto-recovery including Cycle-by-Cycle current limiting (OCP), over load protection (OLP),  VDD under voltage lockout (UVLO), over temperature protection (OTP), and over voltage (fixed or adjustable) protection (OVP).  Excellent EMI performance is achieved with On-Bright proprietary frequency shuffling technique.

The tone energy at below 20KHZ is minimized in the design and audio noise is eliminated during operation.


OB2506 is offered in SOT23-6 packages.


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

   High precision constant voltage and current regulation at universal AC input

   Multi-mode PWM/PFM operation for efficiency improving

   Programmable  CC regulation

   Audio Noise Free Operation

   Built-in line compensation for tight CC regulation

   System work in DCM mode

   Built-in leading edge blanking (LEB)

   Ultra low start-up current and low operating current.

   Comprehensive protection coverage with auto-recovery

o    On-chip OTP

o    VCC over voltage protection

o    VCC under voltage lockout with hysteresis (UVLO)

o    Cycle-by-Cycle current limiting

o    Output over voltage protection



Offline AC/DC flyback converter for

   General power supply

   Power Adapter