OB2279 Current Mode PWM Control IC

OB2273R is a highly integrated current mode PWM control IC optimized for high performance, low standby power and cost effective offline flyback converter applications. PWM switchingfrequency at normal operationis 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 operational current contribute to a reliable power on startup and low standby design with OB2273R. OB2273R offers complete protection coveragewith auto-recovery including cycle-by-cycle current limiting (OCP), over temperature protection (OTP), over load protection (OLP), output diode short protection, ground pin open protection, programmable VDD over voltage protection (OVP), and VDD under voltage lockout (UVLO). 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. OB2273R is offered in SOT23-6 package

Key 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 minimum standby power design
• ■ Audiblenoise free operation
• ■ Forced pulse generation
• ■ Fixed 65KHz (typical)switching frequency
• ■ Comprehensive protection coverage
• o VDD Under Voltage Lockout with hysteresis (UVLO)
• o Cycle-by-cycle over current protection
• o Over temperature protection (OTP) with auto-recovery
• o Over load protection (OLP) with auto-recovery
• o Output diode short protection with auto-recovery
• o Ground pin open protection with auto-recovery

Applications

• Offline AC/DC flyback converter for
• ■ TV Power
• ■ Power Adapter
• ■ Set-Top Box Power Supplies
• ■ Open-frame SMPS

Part Numbers and Specifications

Product family: On-Bright official page