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 . WS2295B 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) ? low standby power ? current mode operat ion ? advanced frequency jitter ing control ? secondary rectifier short protection ? cycle by cycle over current protection (ocp) ? cs open protection ? over temperature protection(otp ? soft-start function ? vdd over voltage protection and clamp ? under voltage lockout with hysteresis (uvlo ? wide operation voltage (7.5-34v) ? driver output clamped(13v) ? soft-driver function for lower emi ? frequency jitter ing ? constant output power limited ? over load protection(olp) applications universal switch power supply and offline ac/dc flyback converter: ? battery charger ? power adaptor ? set-top box power supplies ? open-frame smps description t he WS2295B is a highly integrated current mode pwm switch 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 contribute to minimiz e the power consumption ( <75mw ) and meet the efficiency standard of doe or erp vi . t he ws229 5 b 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 avoid s 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 ws229 5 b 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 . 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 ws229 5 b 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 WS2295B is available in dip7 package. WS2295B switch power supply pwm controller
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 2 / 9 WS2295B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics typical application circuit pin configuration and marking information t he WS2295B is available in dip7 package . the top marking is shown as below: pin definition pin name pin no. pin type function description nc 1 nc hanged out vdd 2 power power supply fb 3 feedback input feedback input pin. the pwm duty cycle is determined by voltage into this pin and the current-sense signal at pin 4 cs 4 current monitoring current monitoring feed-back input pin. to determine whether to reach the limit value . drian 5/6 drain the drain terminal of power mosfet ,connected with the transformer primary side. gnd 7 g round g round WS2295Bd7p product code a product code x internal code bcy internal code for qc y mx d/c
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 3 / 9 WS2295B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics internal block diagram g n d vd d 5 .5 v in te rn a l su p p l y u vl o vdd_ovp vd d _ l o w o sc o l p fb vd d _ l o w bu rst mo d e vd d _ l o w c s l eb sl o p e co mp o c p sbd sh o rt pw m l o g i c so ft d ri ve r otp drain cs otp ovp 100u 1v i_ sa ve 2.5v clamp ordering information package marking part number 7 -pin dip-7 , pb-free ws229 5b d7p ws 229 5b d7 p dip-7 output power note: the above data was tested in the adapter which in ambient temperature of 50 degrees celsius and enough heat radiation 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 product 230vac 15% 85-265vac adapter 1 adapter 1 WS2295B 18w 12w
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 4 / 9 WS2295B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics v sense sense input voltage -0.3~7 v v drain drain pin voltage -0.3~ 6 00 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 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 in the recommended operating conditions section are not implied. exposure to absolute maximum-rated conditions for extended periods may affect device reliability. esd information symbol parameter value unit v esd-hbm human body model on all pins 3 kv v esd-mm machine model on all pins 300 v electrical characteristics supply voltage (vdd) symbol parameter test condition min typ max unit 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=1 3 v 4 10 ua i_vdd_op operation current vdd=16v, v fb = 3 v 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
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 5 / 9 WS2295B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics fosc frequency vdd=16v fb=3.2v 60 65 70 khz d_max m ax duty vdd=16v fb=3.2v 68 7 5 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 5 % ? f_vdd frequency variation versus vdd vdd = 12 to 25v 5 % thermal protection t_shutdown thermal shutdown temperature 150 power mosfet section bvdss mosfet drain-source breakdown voltage 6 00 v ron static drain to source on resistance ws2 295b 3.4 4.5 ohm idss output clamp voltage 10 ua
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 6 / 9 WS2295B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics application information the ws229 5 b is a highly integrated and high performance current mode pwm switch ic. it is applied for small and medium-sized power < 18 w 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 ws229 5 b also ha s multiform auto-recovery protection. the main function s are described as below. startup current and startup control startup current of the WS2295B 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 1206 resistor of 1.5 m ? could be used together with a vdd capacitor to provide a fast startup and low power dissipation solution. operating voltage t he WS2295B covers wide supply voltage from 7.7v to 34v, which helps easing the transform design, and a same transform can be used to design different output voltage, so that the compatibility is improved operating current the operating current of the WS2295B 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 ws229 5 b 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 ws229 5 b 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 ws229 5 b. 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 7 / 9 WS2295B 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 ws229 5 b will shut down after a few cycles. when the secondary rectifier is short , the ws229 5 b will be in protection state after 8 pulse periods of vdd. the controller enters into uvlo auto re covery until the fault is removed. gate driver gate pin of the ws229 5 b 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 ws229 5 b. 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. 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 8 / 9 WS2295B product description winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics winsemi microelectronics package information dip7 package outline dimensions winsemi symbol dimensions in millimeters dimensions in inches min max min max a 9.00 9.50 0.354 0.374 b 6.10 6.60 0.240 0.260 c 3.0 3.4 0.118 0.134 a1 1.474 1.574 0.058 0.062 a2 0.41 0.53 0.016 0.021 a3 2.44 2.64 0.096 0.104 a4 0.51typ 0.02typ a5 0.99typ 0.04typ c1 6.6 7.30 0.260 0.287 c2 0.50typ 0.02typ c3 3.00 3.40 0.118 0.134 c4 1.47 1.65 0.058 0.065 d 7.62 9.3 0.300 0.366 d1 0.24 0.32 0.009 0.013 d2 7.62typ 0.3typ
www.winsemi.com tel : +86-755-8250 6288 fax : +86-755-8250 6299 9 / 9 WS2295B 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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