c o p y r igh t @ w i n s em i microelectronics c o . , lt d . , a l l ri g h t r e s er v ed . w s2293b product description 0322 winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics features ? low startup current (4ua) ? low operation current (1.7ma) ? 0.9ma operation current at no-load ? standby power <75mw ? current mode operat ion ? advanced frequency jitter ing control ? patented rt pin energy saving technology ? secondary rectifier short protection ? external programmable otp and ovp ? cycle by cycle over current protection (ocp) ? cs open protection ? over temperature protection(otp ? soft-start function ? vdd over voltage protection and clamp ? vdd under voltage lockout with hysteresis (uvlo ? wide operation voltage (7.5-34v) ? driver output clamped (13v) ? soft-driver function for lower emi ? constant output power limited ? over load protection(olp) ? maximum driver capability: 60w applications universal switch ing mode power supply and offline ac/dc flyback converter: ? battery charger ? power adaptor ? set-top box power supplies ? open-frame smps description t he WS2293B is a highly integrated current mode pwm control ic which is optimized for high performance. it is applied for small and medium-sized power supply devices, for example , the power adapt e r. f or lower standby power consumption and higher energy saving requirement , the ic has the burst mode function and very low startup current and operating current. at the condition of no load or light load, the ic operates in extended burst mode to minimize switching loss by lower the switching frequency. the patented technolog ies of energy-saving at no-load and rt pin energy - saving contribute to minimiz e the power consumption ( <75mw ) and meet the efficiency standard of doe or erp vi . t he WS2293B applies advanced frequency jitter ing control to improve emi performance at half load and light-load . b esides, it covers wide supply voltage ( 7.5-3 4 v ), which greatly facilitate the transformer design and the compatibility of the system . the internal synchronous slope compensation circuit improves system large signal stability and reduces the possib ility of the 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 and thus greatly reduces the external component count and system cost in the design. t he WS2293B offers complete protection coverage with automatic self-recovery feature including cycle by cycle over current protection (ocp), over load protection (olp), over temperature protection (otp), vdd over voltage protection (ovp) , under voltage lockout (uvlo) , secondary r ectifier s hort p rotection , and e xternal programmable otp and ovp with high precision . the gate-driven output is clamped to maximum 13v to protect the external mosfet. excellent emi performance is achieved by using the frequency j itter and the soft-switching at the totem pole gate drive output. the audio energy at below 20kh z is minimized in the design and audio noise is eliminated during operation. the WS2293B can be used as the best alternative products of the linear power supply or the rcc-mode power to improve the whole performance of the switch ing power system and lower the cost. t he WS2293B is available in sot23-6 package. switch ing mode power supply pwm controller WS2293B
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 2 / 3 w s2293b product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics typical application circuit n ote diode, zener and ntc resistor in the dashed box are o ptional components , which can be used for e xternal programmable otp and ovp . pin configuration and marking information t he WS2293B is available in sot23-6 package . the top marking is shown as below: pin definition pin name pin no. pin type function description gnd 1 g round g round fb 2 feedback input feedback input pin. the pwm duty cycle is determined by voltage into this pin and the current-sense signal at pin 4 r t 3 p rotection setting u sed to set e xternal programmable otp and ovp; connect to auxiliary winding through diode and zener for a ccurate output ovp; connect to ntc resistor for a ccurate otp; m ust be floated when not in use. sense 4 current monitoring current sense input. the current sense resistor between this pin and gnd is used for current limit setting. vdd 5 power power supply gate 6 output gate driver output for external power mosfet. 2293b product code x product code ym production date xx internal code for qc
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 3 / 10 WS2293B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics internal block diagram ordering information package marking part number 6-pin sot23-6, pb-free 2293b WS2293B yp recommended operation conditions s ymbol p arameter v alue u nit vdd vdd supply voltage 10~3 0 v t a operating temperature -20~85 absolute maximum ratings symbol parameter value unit vdd dc power supply 3 4.5 v v fb fb input voltage -0.3~7 v v sense sense input voltage -0.3~7 v v ri ri input voltage -0.3~7 v t j operation junction temperature -20~150 t stg storage temperature -40~150 v cv vcc clamp voltage 3 5.5 v i cc vcc clamp continuous current 10 ma note : stresses above those listed absolute maximum r atings may cause permanent damage to the device. these are stress ratings only, functional operation of the device should not over these or any of these absolute maximum ratings . operating above the absolute maximum-rated conditions may affect device reliability. gnd vdd 5.5v internal supply uvlo vd d _ ovp vdd_low osc olp fb vdd_low burst mode vdd_low cs leb slope comp ocp sbd short pwm logic soft driver gate rt otp ovp 1 0 0 u 1 v i_save 2 .5 v cla mp otp
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 3 / 10 WS2293B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics esd information symbol parameter value unit v esd-hbm human body mode on all pins 3 kv v esd-mm machine mode on all pins 300 v electrical characteristics symbol parameter test condition min typ max unit supply voltage (vdd) vdd_op operation voltage 3 4 v uvlo_on turn on threshold voltage 7.2 7.9 9.0 v uvlo_off turn-off threshold voltage 1 4 . 0 1 5 . 0 1 6 . 0 v i_vdd_st start up current vdd=13v,ri=100k 4 10 ua i_vdd_op operation current vdd=16v, v fb =3v gate with 1nf to gnd 1.7 2.5 ma vdd_ovp 3 4 .5 v vdd_clamp vdd zener clamp voltage ivdd=10ma 35.5 v feedback input section v fb _open v fb open loop voltage vdd=16v,fb open, 4.3 5. 0 5.6 v i fb _short fb pin short current fb shorted to gnd 0.2 2 0.3 1 5 0. 41 ma v th _pl power limiting fb threshold vdd=16v 3.2 3.65 4.0 v t d _pl power limiting debounce vdd=16v fb open 48 60 72 ms z fb _in input impedance vdd=16v fb=2v/3v cs open 13 16.5 20 k ? current sense section tleb leading edge blanking time 330 ns t d _oc ocp control delay gate with 1nf to gnd 70 ns v th _oc ocp threshold fb 3.4v 0.690 0.740 0.790 v max_oc max_ocp for line comp fb 3.4v 0.9 0.95 1 v vth_sbd cs threshold for sbd short vdd=16v 2.0 v td_sbd d elay of sbd short protect 8 pwm cycle 8 clk oscillator section fosc frequency vdd=16v fb=3.2v 60 65 70 khz d_max m ax duty vdd=16v fb=3.2v 70 75 82 % jitter period for 65k 4 ms jitter range for 65k 5 % fosc_bm burst mode frequency vdd= 16 v, fb fall from 2v to burst 22 khz ? f_temp frequency variation versus temp. deviation temp = -20 to 85 o 5 % ? f_vdd frequency variation versus vdd vdd = 12 to 25v 5 %
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 3 / 10 WS2293B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics thermal protection t_shutdown thermal shutdown temperature 150 rt section i_rt rt source current vdd=16v o rt<1.1v 95 100 105 ua vth_otp rt low protection vdd=16v o rt fall from 1.2v 0.95 1 1.05 v vth_ovp rt high protection vdd=16v o rt rise from 1.5v 1.6 2.1 2.6 v rt_float rt floating voltage vdd=16v 1.1 1.3 1.5 v i_rt_sink rt sink current @ clamp vdd=16v o rt=2.1v 135 ua td_rt d elay for rt protection 8 clk cycle 8 clk gate output section vol output voltage low vdd = 16v, io = -20ma 0.8 v voh output voltage high vdd = 16v, io = 20ma 9 v vclamp output clamp voltage vdd = 20v 11 13 14.5 v tr rising time vdd = 16v, gate with 1nf to gnd 635 ns tf falling time vdd = 16v, gate with 1nf to gnd 105 ns
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 3 / 10 WS2293B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics application information the WS2293B is a highly integrated and high performance current mode pwm control ic. it is applied for small and medium-sized power <6 0w supply devices, for example, the power adapter and chargers . the low startup current, operation current and burst mode function at the condition of no load and l ight load can decrease the standby power of the system, and improve the power conver sion efficiency. the patented technolog ies of energy-saving at no-load and rt pin energy - saving contribute to minimiz e the power consumption ( <75mw ) and meet the efficiency standard of doe or erp vi . the internal synchronous slope compensation and the leading edge blanking function of the sense pin not only decrease the component number, but also improve the stability of the system and avoid the harmonics generation. t he WS2293B also ha s multiform auto-recovery protection. the main function s are described as below. startup current and startup control startup current of the WS2293B is designed to be very low 4ua so that vdd could be charged up above uvlo threshold level and starts up quickly. a large value startup resistor can therefore be used to minimize the power loss, predigest the design of startup circuit and provide reliable startup in application. for the design of ac/dc adaptor with universal input range, a startup resistor of 2 m ? , 1/8 w could be used together with a vdd capacitor to provide a fast startup and low power dissipation solution. operating voltage t he WS2293B covers wide supply voltage from 7.7v to 34v, which helps easing the transform er design, and a same transform er can be used to design different output voltage, so that the compatibility is improved . operating current the operating current of the WS2293B is very low. good efficiency is achieved with low operating current together with extended burst mode control circuit which can decrease the value of vdd capacitor. soft-start as soon as vdd reaches uvlo (on), the soft-start function operates; the peak current is then gradually increased from zero. every restart attempt is followed by 4ms soft-start. burst mode at very light load or no load condition, the ic operates in burst mode. in this condition, the voltage at fb is below burst mode threshold level, thus system goes into burst mode. the gate dive s output switch ing only when v dd voltage drops below a preset level or fb input is active to output an on state. otherwise the gate drive remains at off state to minimize the switching loss thus reduce the standby power consumption. the frequency control also eliminates the audio noise at any load conditions . advanced frequency jitter ing control t he WS2293B integrates the maximum operating frequency of 65 khz . the frequency jitter ing range is in proportion to the switching frequency in traditional pwm controller , so that at half load or ligh t load , the switching frequency is decrease d, and the frequency jitter ing range is also decreased, which deteriorate s the emi performance . the WS2293B applies advanced frequency jitter ing control to keep better emi performance at all load condition. current sensing and leading edge blanking cycle-by-cycle current limiting is offered in WS2293B. the switch ing current is detected by a sense resistor at the sense pin. the internal leading-edge blanking chops off the sense voltage spike at initial mosfet on state due to snubber diode circuit reverse recovery and thus reduce the external rc filter circuit. the current limit ation comparator is
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 3 / 10 WS2293B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics disabled and cannot turn off the external mosfet during the blanking period. pwm duty cycle is determined by voltage level at sense pin and fb pin. internal synchronized slope compensation built-in slope compensation circuit adds slope voltage onto the current sense input voltage for pwm generation. this greatly improves the close loop stability at ccm and prevents the sub-harmonic oscillation and thus reduces the output ripple voltage. cs open protection & secondary rectifier short protection when the cs pin is opened, the WS2293B will shut down after a few cycles. when the secondary rectifier is short , the WS2293B will be in protection state after 8 pulse periods of vdd. the controller enters into uvlo auto re covery until the fault is removed. rt pin protection setting (otp and ovp) t he WS2293B offers e xternal programmable otp and ovp through rt pin. t he rt pin generate s 100ua current and connects to a ntc resistor for e xternal programmable otp. w hen the voltage of rt is lower than 1.0v, the system starts the protection mode; when the secondary rectifier is off and the voltage of rt is higher than 2.1v, the system also is in to protection and connects to auxiliary winding through diode and zener for e xternal programmable ovp. t o avoid the i nterference with otp, the voltage of zener should be higher than the highest voltage of normal value with a margin of 3v or above, which is to ensure that there is no current from zener to the rt pin in the normal operating state . t he rt pin m ust be floated when not use d . gate driver gate pin of the WS2293B is connected to the gate of an external mosfet . if the gate drive capacity is too weak will cause higher switch ing loss of mosfet , while too strong gate drive output cause emi problem . a good tradeoff between output capacity and dead time control is achieved through the design of the built-in totem pole driver in the WS2293B. the low standby dissipation and good emi system design is easier to achieve through this dedicated devi c e. for mosfet gate protection, an internal 13v clamp is added. protection controls good power supply system reliability is achieved with auto-recovery protection features including cycle-by-cycle current limiting (ocp), over load protection (olp), over temperature protection (otp), cs open protection, secondary rectifier short protection , under voltage lockout on vdd (uvlo), , and vdd over voltage protection & vdd clamp, and e xternal programmable otp and ovp . internal line voltage compensation of ocp helps to achieve constant output power limit over the universal input voltage range.
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 2 / 3 w s2293b product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics package information sot23-6 package outline dimensions winsemi symbol dimensions in millimeters dimensions in inches min max min max a 2.72 3.12 0.107 0.123 b 1.40 1.80 0.055 0.071 c 1.00 1.20 0.039 0.047 a1 0.90 1.00 0.035 0.039 a2 0.30 0.50 0.012 0.020 b1 2.60 3.00 0.102 0.118 b2 0.119 0.135 0.005 0.005 c1 0.03 0.15 0.001 0.006 c2 0.55 0.75 0.022 0.030 d 0.03 0.13 0.001 0.005 d1 0.30 0.60 0.012 0.024 d2 0.25typ 0.01typ d3 0.60 0.70 0.024 0.028 a a1 a2 b 1 b b2 c2 r c c 1 d r1 r2 d1 d3 d 2 2 3 1 unit:mm
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 3 / 10 WS2293B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics note: 1. we strongly recommend customers check carefully on the trademark when buying our product, if there is any question, please don't be hesitate to contact us. 2. please do not exceed the absolute maximum ratings of the device when circuit designing. 3. winsemi microelectronics co., ltd reserved the right to make changes in this specification sheet and is subject to change without prior notice. contact: winsemi microelectronics co., ltd. add: room 1002, east, phase 2, hightech plaza,tian-an cyber park,chegongmiao, futian, shenzhen, p.r. china post code : 518040 tel : +86-755-8250 6288 fax : +86-755-8250 6299 web site : www.winsemi.com
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