?on-bright electronics confidential preliminary datasheet ob_doc_ds_227601 - 1 - OB2276 high performance current mode pwm controller general description OB2276 is a highly integrated current mode 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 OB2276. OB2276 offers complete protection coverage with auto-recovery including cycle-by-cycle current limiting (ocp), over load protection (olp), brownout protection, and vdd under voltage lockout (uvlo). it also pr ovides latch shut down mode protection include fixed/adjustable vdd over voltage protection (ovp), over temperature protection (otp) and output over voltage protection. excellent emi performance is achieved with on-bright proprietary frequency shuffling technique. the tone energy at below 22khz is minimized in the design and audio noise is eliminated during operation. OB2276 is offered in sop8 package. features power on soft start reducing mosfet vds stress frequency shuffling for emi extended burst mode control for improved efficiency and minimum standby power design audio noise free operation fixed 65khz switching frequency comprehensive protection coverage o vdd under voltage lockout with hysteresis (uvlo) o cycle-by-cycle over current threshold setting for constant output power limiting over universal input voltage range o overload protection (olp) with auto- recovery o brownout protection with auto-recovery o fixed vdd ovp with latch shut down o adjustable vdd ovp with latch shut down o over temperature protection with latch shut down o output over voltage protection with latch shut down applications offline ac/dc flyback converter for battery charger power adapter set-top box power supplies open-frame smps typical application
?on-bright electronics confidential preliminary datasheet ob_doc_ds_227601 - 2 - OB2276 high performance current mode pwm controller general information pin configuration the OB2276 is offered in sop8 package, shown as below. 1 2 3 4 8 7 6 5 vcc gnd gate cs bo rt fb demag ordering information part number description OB2276cp sop8, pb-free in tube OB2276cpa sop8, pb-free in t&r package dissipation rating package r ? ja( /w) sop8 150 absolute maximum ratings parameter value vdd dc supply voltage vovp-1v vdd zener clamp voltage note vdd_clamp+0.1v vdd dc clamp current 10 ma fb input voltage -0.3 to 7v sense input voltage -0.3 to 7v bo input voltage -0.3 to 7v rt input voltage -0.3 to 7v min/max operating junction temperature tj -40 to 150 min/max storage temperature tstg -55 to 150 lead temperature (soldering, 10secs) 260 note: vdd_clamp has a nominal value of 34v. stresses beyond those listed under ?absolute maximum ratings? may cause permanent damage to the device. these are stress ratings only, functional operation of the device at these or any other conditions beyond those indicated under ?recommended operating conditions? is not implied. exposure to absolute maximum-rated conditions for extended periods may affect device reliability. OB2276 x x x current mode pwm controller with brownout package c:sop8 blank:tube a: tape/reel packing package pb-free p:pb-free
|
