OB2269DRG

OB2269 combines a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective off line flyback converter applications. PWM switching frequency at normal operation is externally programmable and trimmed to tight range. At no load or light load condition, the IC operates is 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 OB2269. 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 application. OB2269 offers complete protection coverage with automatic self recovery feature including Cycle - by - Cycle current limiting(OCP), over load protection(OLP), VDD under voltage lockout (UVLO), over temperature protection (OTP), and over voltage protection (OVP). The Gate - drive output is clamped at 18V to protect the power MOSFET. In OB2269, OCP threshold slope is internally optimized to reach constant output power limit over universal AC input range. Excellent EMI performance is achieved with internal frequency jitter technique and soft switching control at the totem pole gate drive output. The tone energy at below 22KHz is minimized in the design and audio noise is eliminated. OB2269 is offered in both SOP - 8, MSOP - 8 and DIP - 8

Applications

• Offline AC/DC flyback converter for AC/DC Adapter
• Set - Top Box Power Supplies
• Auxiliary Power Supply
• Open - frame SMPS
• Battery Charger

Key features

• Extended Burst Mode Control For Improved Efficiency and Minimum Standby Power Design
• Power - on Soft Start Reducing MOS Stress
• Audio Noise Free Operation
• External Programmable PWM Switching Frequency
• Low VDD startup and operating current
• Frequency jitter to Minimize EMI
• Leading edge blanking on current sense
• Internal Synchronized Slope Compensation
• Low VIN/VDD Startup Current(6.5 μA) and Low Operating Current(2.0 mA)
• Complete Protection Coverage With Auto Self - Recovery
• -VDD Under Voltage Lockout with Hysteresis (UVLO)
• Cycle - by - Cycle over current Protection
• Over load Protection (OLP)
• Over Temperature Protection (OTP)
• VDD Over Voltage Protection (OVP)