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?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 1 - OB2201 high performance qua si-resonant pwm controller general description OB2201 is a high performance flyback quasi- resonant (qr) controller optimized to achieve high efficiency in the universal input range and full loading range with effective system cost. at full loading, the ic operates in fix frequency (52khz) ccm mode in the low line input range and operates in qr mode in high line input range. in this way, high efficiency in the universal input range at full loading can be achieved. at normal load condition, it operates in qr mode. to minimize switching loss, the maximum switching frequency in qr mode is internally limited to 90 khz. when the loading goes low, it operates in pfm mode for high power conversion efficiency. when the load is very small, the ic operates in ?extended burst mode? to minimize the standby power loss. as a result, high conversion efficiency can be achieved in the whole loading range. OB2201 offers comprehensive protection coverage including cycle-by-cycle current limiting (ocp), vcc under voltage lockout (uvlo), output over voltage protection (ovp), over temperature protection (otp), over load protection (olp), vcc over voltage protection (vcc ovp), vcc clamp, and gate clamp. OB2201 also features protections against pin open and short conditions on selected pins. OB2201 is offered in sop-8 and dip-8 packages. feat ures multi-mod e operation: ? at full loadi ng, fix frequency (52khz) ccm operation @ low line and qr mode operation @ high line input ? qua si-resonant operation at normal load ? pulse f requency modulation (pfm) operation at light load ? burst mo de at no load adaptive freque ncy shuffling and slope compensation @ fix frequency ccm mode programma ble otp with latch shutdown fixed 4ms so ft-start 2.5us mini mum off time 12.5us maximum on tim e limit 55us maximum off time limit 90khz maxi mum frequency limit internal le ading edge blanking output over voltage protection 800ma pea k current sink/source capability applications offline ac/dc flyback converter for powe r adaptor and open-frame smps set-top box powe r supplies nb/dvd ty pical application rt gn d vcc 1 2 3 4 8 7 6 5 dem gat e fb cs ri ac ob22 01 ntc product specific ation m?w3^vu0t^u5[py?b?g ?pqls? http://
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 2 - OB2201 high performance qua si-resonant pwm controller general information pin configur ation the pin map of OB2201 in dip8 and sop8 package is shown as below. ordering information part number des cription OB2201ap 8 pin dip, pb free in tube OB2201 cp 8 pin sop, pb free in tube OB2201 cpa 8 pin sop, pb free in t&r not e: all devices are offer ed in pb-free package if not otherwise noted. packag e dissipation rating packag e r ja ( /w) dip8 90 sop8 150 absolu te maximum ratings parameter value vcc ze ner cl amp voltage 29 v vcc cl amp continuous current 10 ma ri input voltage -0.3 to 7v fb input voltage -0.3 to 7v cs input voltage -0.3 to 7v dem input voltage -0.7 to 7v rt input volt age -0.3 to 7v maximum o perating junction temperature t j 150 o c min/max storage te mperature t stg -55 to 150 o c lead te mperature (soldering, 10secs) 260 o c not e: stresses be yond those listed under ?absolute maximum ratings? may cause per manent damage to the device. these are stress ratings only, functional operation of the device at these or any other co nditions beyond those indicated under ?recommended operating condi tions? is not implied. exposure to absolute maximum-ra ted conditions for extended periods may affect device reliability. ob 2201 x x x high p erformance qusi-resonant pwm controller package a:dip8 c:so p8 b lank:tube a: tape/reel pa cking package pb free blank:normal p:lead-free m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 3 - OB2201 high performance qua si-resonant pwm controller marki ng information yww OB2201cp s sop8 y: year code (0-9) ww: week code (1-52) c: sop8 p:lead-free s: internal code dip8 y: year code (0-9) ww: week code (1-52) a: dip8 p:lead-free s: internal code yww OB2201ap s termi nal assignments pin num pin name i/o des cription 1 ri i a resistor connected between ri and gnd sets the internal frequency and timer. the resistor is recommended to be set in the vicinity of 20k ohm. 2 fb i feedback input pin. pwm duty cycle is determined by voltage level into this pin and current-sense signal level at pin 3. 3 cs i current sense input. 4 gnd p ground for internal circuitry. 5 gate o totem-pole gate drive output for power mosfet. 6 vcc p chip dc power supply pin. 7 dem i transformer core demagnetization detection pin. this pin is also used for output over voltage protection (ovp). 8 rt i over temperature protection pin. c onnected through a ntc resistor to gnd for over temperature latch shutdown. m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 4 - OB2201 high performance qua si-resonant pwm controller block di agram vd d 6 uv lo ga te so ft driver 5 tr immed voltage/current reference m ode selection po r re gulator int ernal supply de m 7 v alley detector loa d ovp fb 2 r s qb q i nternal reference ol p ti mer, logic, & fault management gn d 4 cs 3 le b 4 ms soft startup a daptive frequency shuffling ri 1 ot p 8 rt recommended operating condition sy mbol parameter min max unit vcc vcc supply voltage 12 28 v t a operating a mbient temperature -20 85 o c m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 5 - OB2201 high performance qua si-resonant pwm controller electrical characte ristics (t a = 25 o c, vcc=1 6v, ri=20k ohm if not otherwise noted) sy mbol parameter test conditi ons min ty p max unit supply voltage section (vcc pin) i_vcc_sta rtup vcc start up current vcc =uvl o(off)-1.5v, measure current into vcc - 5 15 ua i_vcc_ quiet operation current without switching fb=3v - 2.0 4.0 ma i_vcc_ operation operation current with switching fb=3v, 1nf load at gate - 3.0 5.0 ma uvlo (on) vcc under voltage lockout enter 8.0 9.0 10.0 v uvlo (off) vcc under voltage lockout exit (startup) 15 16 17 v ovp(on) vc c over voltage protection enter 28 v vcc_ clamp vcc zener clamp voltage i_vcc = 5 m a 29 v feedb ack input section (fb pin) a vcs pwm input g ain v fb / v cs - 3.5 - v/v v fb_ open fb open vol tage -- 5.3 -- v i fb _short fb pin short ci rcuit current short fb pin to gnd, measure current -- 1.5 - ma v th _bm_o n burst mode on threshold - 0.8 - v v th _bm_off burst mode off threshold - 0.7 - v v th _pl powe r limiting fb threshold voltage - 4.4 - v t d _pl powe r limiting debounce time -- 80 -- ms z fb _in input impedance - 4 - kohm curre nt sense input section (cs pin) t_blan king cs input leading edge blanking time - 300 - ns v th _ ocp_zero_ ontime internal current limiting threshold zero duty cycle 0.41 5 0.45 0.48 5 v v th _o cp_max internal current limiting threshold maximum duty cycle - 0.80 - v v th _cs _min flodback mode and burst mode cs peak 0.3 v t d _oc over cu rrent detection and control delay cl=1nf at gate, - 100 -- ns demagn etization detection section (dem pin) v th _dem dema gnetization comparator threshold voltage -- 75 -- mv v de m _clamp(neg) neg ative clamp voltage - -0.7 - v v de m _clamp(pos) positive clamp voltage - 6.0 - v t supp suppressio n of the transformer ringing at start of secondary stroke -- 2.5 -- us t out timeout afte r last demag transistion -- 5 -- us t de m_delay demag propagation delay - 250 - ns m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 6 - OB2201 high performance qua si-resonant pwm controller v th _ovp output ovp trigger point - 3.75 - v t_ovp_del ay number of subsequent cycles to be true ovp - 4 - cycle soft start section t_s oft internal soft startup 4 ms timer sectio n ri_ra nge operating ri resistor range 14 20 26 kohm v_ri_op en ri open voltage 2.0 v fburst burst mode switching frequency ri=20k - 22 - khz fmax_ qr_h freq uency high clamp in qr mode ri=20k 82 90 98 khz fmin _qr_l freq uency low clamp in qr mode ri=20k 47 52 57 khz f s huffle /f fmin_ qr_l frequen cy shuffling range -4 +4 % ton_m ax maximum on time ri=20k 10 12.5 15 us toff_max maximum off time ri=20k 40 55 75 us g_pfm pfm mode frequency modulation slope versus control voltage - 90 - khz/ v ov er temperature protection i_rt output current of rt pin, ri=20k 100 ua vth_otp otp threshold voltage 1.00 1.05 1.10 v v_rt_ open rt pin open voltage 3.5 v latc h protection v_latch_ release vcc latch release voltage -- 6.3 -- v ivdd(latc h) vcc current when latch off vcc=v_latch_release+1v - 45 - ua gate drive output (gate pin) vol output low level io = 100 ma (sink) - - 1 v voh output high level io = 100 ma (source) 7.5 - - v vg_clamp output cla mp voltage level vcc=20v - 16.5 - v t_r output rising time cl = 1nf - 80 - ns t_f output falling time cl = 1nf - 30 - ns m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 7 - OB2201 high performance qua si-resonant pwm controller charact erization plots i op_n vs vdd 0 1 2 3 4 5 4122028 vdd(v) iv dd(ma) i startup(ua) vs temperature( ) 5.0 6.0 7.0 8.0 9.0 -40 0 40 80 120 temperature( ) i startup(ua) u vlo(on)(v) vs temperature( ) 8. 60 8.80 9.00 9.20 -40 0 40 80 120 t emperature( ) u vlo(on)(v) u vlo(off)(v) vs temperature( ) 15.60 15.75 15.90 16.05 16.20 -40 0 40 80 120 temperature( ) uv lo(off)(v) f _qr_clamp_l(khz) vs temperature( ) 49 .00 50.50 52.00 53.50 -40 0 40 80 120 t emperature( ) f _qr_clamp_l(khz ) vt h_load_ovp(v) vs temperature( ) 3.75 3.80 3.85 3.90 -40 0 40 80 120 temperature( ) v th_load_ovp(v) i _rt(ua) vs temperature( ) 98.5 100.0 101.5 103.0 - 40 0 40 80 120 t emperature( ) i _rt(ua) f min_qr_l vs ri 30. 0 40.0 50.0 60.0 70.0 80.0 90.0 12 16 20 24 28 32 ri (kohm) f min_qr_l(khz ) m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 8 - OB2201 high performance qua si-resonant pwm controller operati on description qua si-resonant (qr) converter typically features lower emi and higher power conversion efficiency compared to conventional hard-switched converter with a fixed switching frequency. OB2201 is a highly integrated qr controller optimized for offline flyback converter applications. the built-in advanced energy saving with high level protection features provide cost effective solutions for energy efficient power supplies. z startup current and start up control startup current of OB2201 is designed to be very low so that vcc could be charged up above uvlo(off) threshold level and device starts up quickly. a large value startup resistor can therefore be used to minimize the power loss yet reliable startup in application. for a typical ac/dc adaptor with universal input range design, a 2m ? , 1/8 w startup resistor could be used together with a vcc capacitor to provide a fast startup and yet low power dissipation design solution. z opera ting current the operating current of OB2201 is as low as 3ma. good efficiency is achieved by the low operating current togethe r with extended burst mode control schemes at no/light load conditions. z multi-mode operation for high effici ency OB2201 is a multi-mode qr controller. the controller changes the mode of operation according to fb voltage, which reflects the line and load conditions. at full load conditions (fb>vth3, figure 1), there are two situations: firstly, if the system input is in low line input range, the ic operates in fix frequency (52khz @ ri=20k ohm) ccm mode. thus, small size transformer can be used with high power conversion effici ency. secondly, if the system input is in high line input range, the ic operates in qr mode. in this way, high power conversion efficiency can be achieved in the universal input range when system is at full loading conditions. at normal operating conditions (vth2 ?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 9 - OB2201 high performance qua si-resonant pwm controller the tra nsformer core demagnetization is detected by monitoring the voltage activity on the auxiliary windings through dem pin. this voltage features a flyback polarity. a new cycle starts when the power switch is activated. after the on time (determined by the cs voltage and fb), the switch is off and the flyback stroke starts. after the flyback stroke, the drain voltage shows an oscillation with a frequency of approximately dp cl 2/1 , where p l is the primary self inductance of the transformer and d c is the capacitance on the drain node. figure 2 the typical d etection level is fixed at 75mv at the dem pin. demagnetization is recognized by detection of a possible ?valley? when the voltage at dem is below 75mv in falling edge. dem detection is suppressed during the ringing suppression time tsupp (please refer to ? ringing suppression timer ? section). z current sensing and leading edge blanking cycle-by-cycle current limiting is offered in OB2201. the switch current is detected by a sense resistor into the cs pin. an internal leading edge blanking circuit chops off the sense voltage spike at initial mosfet on state, the qr current limit comparator is disabled and cannot turn off the external mosfet during the blanking period. z maximum and minimum on-time the minimum on-time of the system is determined by the leb time (typical 300ns, ri=20k). the ic limits the on-time to a maximum time of 12.5us. z maximum frequency clamp according to the qr operation principle, the switching frequency is inversely proportional to the output power. therefore, when the output power decreases, the switching frequency can become rather high without limiting. to meet emi limit and to achieve high efficiency at light loading conditions, the maximum switching frequency in OB2201 is internally limited to 90khz. z ringing suppression timer a ringing suppression timer tsupp is implemented in OB2201. in normal operation, tsupp starts when cs reaches the feedback voltage fb, the external power switch is set to off state. during tsupp, the external power switch remains in off state and cannot be turned on gain. the ringing suppression time is necessary in applications where the transformer has a large leakage inductance, particularly at low output voltages or startup. in OB2201, the ringing suppression timer tsupp is set to 2.5us internally. z ocp compensation the variation of max output power in qr system can be rather large if no compensation is provided. the ocp threshold value is self adjusted lower at higher ac voltage. this ocp threshold slope adjustment helps to compensate the increased output power limit at higher ac voltage. in OB2201, a proprietary ocp compensation block is integrated and no external components are needed. the ocp threshold in OB2201 is a function of the switching on time. for the on time less than 12.5us, the ocp threshold changes linearly from 0.45v to 0.8v. for the on time larger than 12.5us, the ocp threshold is clamped to 0.8v, as shown in figu re 3. (note: ri=20k conditions) figure 3 z adap tive frequency shuffling and slope compensation in OB2201, when the fix frequency ccm mode is touched, the frequency shuffling and slope compensation will be automatically added to the system to improve the emi performance and current loop stability. the magnitude of shuffling m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 10 - OB2201 high performance qua si-resonant pwm controller lies in the range of 4% of 52k hz. when the system leaves fix frequency ccm mode, the frequency shuffling and slope compensation will automatically disappear. z output over voltage protection (ovp) an output over voltage protection (ovp) is implemented by sensing the auxiliary winding voltage at dem pin during the flyback phase. the auxiliary winding voltage is a well-defined replica of the output voltage. the ovp works by sampling the plateau voltage at dem pin during the flyback phase. internal 2.5us delay (plateau sensing) guarantees a clean plateau, provided that the leakage inductance ringing has been fully damped. au xiliary winding dem 8 3. 75v pl ateau sampling last s for 4 subsequent cycles ye s true ovp OB2201 r1 r2 figure 4 if the sample d plateau voltage exceeds the ovp trip level (3.75v), an internal counter starts counting subsequent ovp events. if ovp events are detected in successive 4 cycles, the controller assumes a true ovp and it enters a latch off mode and stops all switching operations. the counter has been added to prevent incorrect ovp detection which might occur during esd or lightning events. if the output voltage exceeds the ovp trip level less than 4 successive cycles, the internal counter will be cleared and no fault is asserted. z over load protection when over load (for example, short circuit) occurs, the feedback current of photo coupler is below minimum value, fb pin voltage approaches its floating pin voltage, then a fault is detected. if this fault is present for more than 80ms, the controller enters an auto-recovery soft burst mode. all pulses are stopped, vcc will drops below uvlo and the controller will try to restart with the power on soft start. it resumes operation once the fault disappears. z ov er temperature protection with latch shutdown a ntc resistor in series with a regular resistor should be connected between rt and gnd for temperature sensing and protection. ntc resistor value becomes lower when the ambient temperature rises. a resistor between ri and gnd sets internal reference current and the timer. the relationship between rt source current and ri resistor fellows below equation: i_rt = 100* ri k 20 ( ua ), with 20k ohm ri sele cted, an internal 100ua current flows through the ntc resistors. the voltage at rt pin becomes lower at high temperature. the internal otp circuit is triggered and shuts down the mosfet when the sensed input voltage is lower than 1.05v. otp is a latched shutdown. z pin floating and short pr otection OB2201 provides pin floating protection for ri, cs, fb, dem, etc., and ri pin short protection. in cases when the pin are floating or ri pin is shorted to ground, gate switching is disabled, thus protect the power system. z external latch trip point by externally forcing a level on pin rt (e.g.., with a signal coming from a temperature sensor) less than 1.05v, OB2201 can be permanently latched- off. to resume normal operation, vcc voltage should go below 6v (typical), which implies to unplug the smps from the mains. z gate drive the gate pin is connected to the gate of an external qr power switch with 0.8a capability. an internal 16.5v clamp is added for mosfet gate protection at high vcc voltage. when vcc voltage drops below uvlo(on), the gate pin is internally pull low to maintain the off state. m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 11 - OB2201 high performance qua si-resonant pwm controller package mechanical data 8-pin plastic dip dimensions in millimeters dimensions in inches sy mbol min max min max a 3.710 5.334 0.146 0.21 a1 0.381 0.015 a2 3.175 3.600 0.125 0.142 b 0.350 0.650 0.014 0.026 b1 1.524 (bsc) 0.06 (bsc) c 0.200 0.360 0.008 0.014 d 9.000 10.160 0.354 0.4 e 6.200 6.600 0.244 0.260 e1 7.320 7.920 0.288 0.312 e 2.540 (bsc) 0.1 (bsc) l 2.921 3.810 0.115 0.15 e2 8.200 9.525 0.323 0.375 m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 12 - OB2201 high performance qua si-resonant pwm controller 8-pin plastic sop dimensions in millimeters dimensions in inches sy mbol min max min max a 1.350 1.750 0.053 0.069 a1 0.050 0.250 0.002 0.010 a2 1.250 1.650 0.049 0.065 b 0.310 0.510 0.012 0.020 c 0.170 0.250 0.006 0.010 d 4.700 5.150 0.185 0.203 e 3.800 4.000 0.150 0.157 e1 5.800 6.200 0.228 0.244 e 1.270 (bsc) 0.05 (bsc) l 0.400 1.270 0.016 0.050 0o 8o 0o 8o m?w3^vu0t^u5[py?b?g ?pqls?
?on-b right electronics confidential datasheet ob_doc_ds_2201a1 - 13 - OB2201 high performance qua si-resonant pwm controller important notice right to make changes on-b right electronics corp. reserv es the right to make corrections, modifications, enhancements, improvements and other changes to its products and serv ices at any time and to discontinue any product or service without notice. customer s should obtain the latest relevant information before placing orders and should verify that such information is current and complete. warranty information on-bright electronics corp. warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with it s standard warranty. testing and other quality control techniques are used to the extent it deems necessar y to support this warranty. except where mandated by government requirements, testing of all parameter s of each product is not necessarily performed. on-bright electronics corp. assumes no liability for application assistance or customer product design. customers are responsible for their products and appl ications using on-bright?s components, data sheet and application notes. to minimize the risks associ ated with customer products and applications, customers should provide adequate design and operating safeguards. life support on-bright electronics corp.?s products are not design ed to be used as components in devices intended to support or sustain human life. on-bright electronics corp. will not be held liable for any damages or claims resulting from the use of its products in medical applications. military on-bright electronics corp.?s products are not designed for use in military applications. on-bright electronics corp. will not be held liable for any damages or claims resulting from the use of its products in military applications. m?w3^vu0t^u5[py?b?g ?pqls?

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