Current Mode PWM Controller
OB2269C is a highly integrated current mode PWM
control IC optimized for high performance, low
standby power and cost effective offline flyback
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
OB2269C. 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 input
removes the signal glitch due to snubber circuit diode
reverse recovery. This greatly helps to reduce the
external component count and system cost in
OB2269C offers complete protection coverage with
automatic self-recovery feature including Cycle-by-
Cycle current limiting (OCP), over load protection
(OLP), over temperature protection (OTP), VDD
over voltage protection (OVP) and under voltage
lockout (UVLO). The Gate-drive output is clamped
at 18V to protect the power MOSFET.
In OB2269C, OCP threshold slope is internally
optimized to reach constant output power limit over
universal AC input range.
Excellent EMI performance is achieved with On-
Bright proprietary frequency shuffling technique
together with soft switching control at the totem pole
gate drive output.
The tone energy at below 20KHZ is minimized in
operation. Consequently, audio noise performance is
OB2269C is offered in both 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
Programmable PWM Switching
Internal Synchronized Slope Compensation
Low VIN/VDD Startup Current(6.5uA) and Low
Operating Current (2.3mA)
Leading Edge Blanking on Current Sense Input
Complete Protection Coverage With Auto Self-
External Programmable Over Temperature
With or Without On-chip VDD OVP for
Under Voltage Lockout with Hysteresis
Gate Output Maximum Voltage Clamp (18V)
Line Compensated Cycle-by-Cycle Over-
current Threshold Setting For Constant Output
Current Limiting Over Universal Input Voltage
Over Load Protection. (OLP)
Offline AC/DC flyback converter for
Laptop Power Adaptor
PC/TV/Set-Top Box Power Supplies