Current Mode PWM ControllerFrequency Shuffling
OB2263 is a highly integrated current mode PWM
control IC optimized for high performance, low
standby power and cost effective offline flyback
converter applications in sub 30W range.
PWM switching frequency at normal operation is
externally programmable and 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 design with
OB2263. A large value resistor could thus be used in
the startup circuit to minimize the standby power.
The internal slope compensation improves system
large signal stability and reduces the possible sub-
harmonic oscillation at high PWM duty cycle output.
Leading-edge blanking on current sense(CS) input
removes the signal glitch due to snubber circuit diode
reverse recovery and thus greatly reduces the external
component count and system cost in the design.
OB2263 offers complete protection coverage with
automatic self-recovery feature including Cycle-by-
Cycle current limiting (OCP), over load protection
(OLP), VDD over voltage clamp and under voltage
lockout (UVLO). The Gate-drive output is clamped
to maximum 18V to protect the power MOSFET.
Excellent EMI performance is achieved with On-
Bright proprietary frequency shuffling technique
together with soft switching control at the totem pole
gate drive output.
Tone energy at below 20KHZ is minimized in the
design and audio noise is eliminated during operation.
OB2263 is offered in SOT23-6, SOP-8 and DIP-8
■ On-Bright Proprietary Frequency Shuffling
Technology for Improved EMI Performance.
■ Extended Burst Mode Control For Improved
Efficiency and Minimum Standby Power Design
■ Audio Noise Free Operation
■ External Programmable PWM Switching
■ Internal Synchronized Slope Compensation
■ Low VDD Startup Current and Low Operating
■ Leading Edge Blanking on Current Sense Input
■ Good Protection Coverage With Auto Self-
o VDD Over Voltage Clamp and Under Voltage
Lockout with Hysteresis (UVLO)
o Gate Output Maximum Voltage Clamp (18V)
o On-Bright Proprietary Line Input Compensated
Cycle-by-Cycle Over-current Threshold Setting
For Constant Output Power Limiting Over
Universal Input Voltage Range.
o Overload Protection (OLP)
Offline AC/DC flyback converter for
■ Battery Charger
■ Power Adaptor
■ Set-Top Box Power Supplies
■ Open-frame SMPS
Confidential to Micro Bridge