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cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 1/11 MC7773N6 cystek product specification current mode pwm controller MC7773N6 description MC7773N6 is a highly integrated current mode pwm control ic optimized for high performance low standby power offline flyback converter applications. to meet the international power conservation requiremen ts, optimized green mode is integrated to improve the efficiency at light or no load conditions with no audible noise. slope compensation is integrated to ensure the stability at high load. lead edge blanking is integrated to prevent the false trigger at the tran sition of the switch. soft switching cont rol at the gate drive can improve the emi performance of the power supply. the gate-drive output is clamped at 12v to protect the power mos. features frequency jitter function to improve emi performance of power supply no-audible-noise green mode control multi operation mode: fixed-frequenc y ccm, green mode and burst mode. no load input power under 100mw internal slope compensation low vdd startup current and low operating current leading edge blanking uvlo 8.5v / 15.5v gate max output voltage clamp at 12v overload protection (olp ) with auto-recovery line compensation over current pr otection (ocp) with auto-recovery over temperature protection (otp) witch latch vdd over voltage protection (ovp) witch latch applications offline ac/dc flyback converter for battery charger power adaptor set-top box power supplies open-frame smps pc 5v standby power ordering information device package shipping MC7773N6 sot-23-6l (pb-free lead plating) 3000 pcs / tape & reel
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 2/11 MC7773N6 cystek product specification typical application circuit pin configuration pin assignment pin name pin number pin function gnd 1 ground fb 2 feedback input pin. the pwm duty cycle is de termined by voltage level into this pin and the current-sense signal at pin 6. pt 3 connected through a ntc resistor to ground for over temperature shutdown/latch control or connected through zener to vdd for adjustable over voltage protection. sense 4 current sense input pin. connected to mosfet current sensing resistor node. vdd 5 chip dc power supply pin. gate 6 totem-pole gate drive output for the power mosfet.
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 3/11 MC7773N6 cystek product specification function block diagram absolute maximum ratings parameter value unit v dd to gnd +29 v v dd clamped current 10 ma v dd clamped voltage 32 v v fb , v sense and v ri to gnd -0.3~+7 v maximum junction temperature (tj max ) -20 ~ +150 c storage temperature range -55 ~ +160 c note stresses beyond those listed under ?a bsolute maximum ratings" may cause permanent damage to the device. recommended operating conditions ? supply voltage, v dd ???????????????????????????+10v to +30v ? operating temperature range??????????????????????.-20 c to +85 c ? power dissipation (r ja =250 c/w) @25 c, fr-4 pcb , 2oz??????????????.0.4w esd information ? human body mode??????????????????????????????2000v ? machine mode????????????????????????????????.200v
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 4/11 MC7773N6 cystek product specification electrical characteristics (t a = 25 c, v dd =16v if not otherwise noted) parameter symbol test conditions min typ max units supply section chip start up current via vdd pin i_set vdd=12v, measure current into vdd pin 3 20 ua operation current i_op vdd=16v,vfb=3v 1.4 ma vdd uvlo enter uvlo_l 7.5 8.5 9.5 v vdd uvlo exit uvlo_h 14.5 15.5 16.5 v vdd ovp vdd_ovp 30 32 34 v vz(vdd clamp voltage) vdd_clp iz(idd)=10ma 30 32 34 v feedback section pwm input gain a_pwm vfb/ vcs 2 v/v vfb open loop voltage vfb_o 4.2 v fb pin short circuit current vfb_s short fb pin to gnd and measure current 0.35 ma burst mode on threshold v_bm_on 0.675 v burst mode off threshold v_bm_off 0.575 v power limiting fb threshold vfb_th_p 3.7 v power limiting delay time t_pl_d 88 ms input impedance r_fb 16 k ? oscillator soft start time t_ss 4 ms burst mode switching frequency f_burst 22 khz normal operation frequency f_nor 60 65 70 khz frequency modulation range f_d_jit 4 % jitter frequency f_jitter 32 hz frequency temperature stability f_d_tem 4 khz current sense section leading edge blanking time t_blank 220 ns sense pin input impedance r_sense 40 k ? over current threshold voltage at zero duty cycle vth_oc_0 fb=3.3v 0.72 0.75 0.78 v over current threshold voltage at max. switching on time vth_oc_1 fb=3.3v 0.9 v over current protect delay t_oc_d cs>vth_oc, fb=3.3v, cl=1nf @gate 120 ns gate output output low level vol io=20ma 1 v output high level voh io=20ma 6 v output voltage clamped level vo_clamp 12 v output rising time tr cl=1nf 175 ns output falling time tf cl=1nf 85 ns pt pin pt pin source current i_pt 95 100 105 a thresh hold of otp v_otp 0.95 1 1.05 v
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 5/11 MC7773N6 cystek product specification otp debounce time t_otp 6 cycle external ovp trigger point vth_ovp 4 v float voltage at pt pin v_pt_fl 2.3 v typical characteristics (t a = 25c, v dd =16v if not otherwise noted.) start current vs vdd voltage uvlo voltage& operation current operation current vs load uvlo (on) voltage vs temp uvlo (off) voltage vs temp
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 6/11 MC7773N6 cystek product specification operation description over-view description the MC7773N6 includes all necessary function to build an ea sy and cost effective solution for low power supplies to meet the international power conservation requirements. start-up current startup current of MC7773N6 is designed to be very lo w so that vdd could be charged up above uvlo (exit) threshold level and device starts up quickly. also a large va lue startup resistor can be used to minimize the power loss. green mode operation patent at light load or no load condition, the switch lo ss become the major loss of the power supply, to reduce the power wasted in light and no load condition, based on a special designed voltage controlled oscillator, green mode operation of the power supply can be achieved by using mc7731n6. the controller will judge the load condition based on the voltage of fb pin. in light load the fb volt age will decrease, when vfb is lower than a set threshold voltage, a fb depending time (tr2) will be generated by the oscillator and decrease the operating frequency of the power supply, the minimum frequency is set about 22khz. the function block and the working waveform can be depicted as below: when v fb decreases further, the power supply will enter into burst mode operation to decrease the power consumed at no load condition. besides there is no audible noise in any load condition.
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 7/11 MC7773N6 cystek product specification built-in slope compensation and frequency shuffling while MC7773N6 works in ccm mode, slope compensa tion and frequency shuffling is activated. the sensed voltage across the sense resistor is used for pwm control, and pulse by pulse current limit, built-in slope compensation circuit adds a voltage ramp onto th e current sense input voltage. this greatly improves the close loop stability and prevents the sub-harm onic oscillation of peak current mode pwm control scheme. to improve the emi performance, the frequenc y of ccm mode is shuffling to 65khz 4%. line slope compensation adjusting the rsense can set the max output power of the power supple mode. the current flowing by the power mosfet has an extra value due to the system dela y t that the current detect ed from the sense pin to power mosfet cut off in the MC7773N6. to guarantee th e output power is a cons tant for universal input ac voltage, there is a positive ramp signal to compen sate the system delay t and the line input. at lower line-input voltage the higher ocp threshold will bring constant power ocp as below. leading edge blanking each time when the power mosfet is switched on, a turn-on spike will inevitably occur on the sense-resistor. to avoid premature termination of the switching pulse, a 300 nsec leading-edge blanking time is built in. conventional rc filtering can theref ore be omitted. during this blanking period, the current-limit comparator is disabled a nd it cannot switch off the gate driver. gate driver the output stage of MC7773N6 is a fa st totem pole gate driver. cross conduction has b een avoided to minimize heat dissipation, increases efficiency and enha nces reliability. the output driver is clamped by an internal 18v zener diode in order to protect powe r mosfet transistors against undesirable gate over voltage. a soft driving waveform is implemented to minimize emi.
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 8/11 MC7773N6 cystek product specification protect functions to increase the reliability of power supply system many protection functions is integrated in this controller, including cycle-by-cycle current limiting (ocp), over load prot ection (olp), over temperature protection(otp), external over voltage protection (ovp) and over voltage clamp, under voltage lockout on vdd (uvlo). at overload condition when fb input voltage exceeds power limit threshold value for more than td_pl (power limit debounce time), the controller reacts to shut down the output power mosfet. device restarts when vdd voltage drops below uvlo limit. vdd is supplied by transformer auxiliary winding output. it is clamped when vdd is higher than threshold value. the power mosfet is shut down when vdd drops below uvlo limit and devi ce enters power on start-up sequence thereafter. pin floating protection for cs, fb, pt is also added. while one of this happens, the gate is turned off. pt pin typical application circuit
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 9/11 MC7773N6 cystek product specification reel dimension carrier tape dimension
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 10/11 MC7773N6 cystek product specification recommended wave soldering condition product peak temperature soldering time pb-free devices 260 +0/-5 c 5 +1/-1 seconds recommended temperature profile for ir reflow profile feature sn-pb eutectic assembly pb-free assembly average ramp-up rate (tsmax to tp) 3 c/second max. 3 c/second max. preheat ? temperature min(t s min) ? temperature max(t s max) ? time(ts min to ts max ) 100 c 150 c 60-120 seconds 150 c 200 c 60-180 seconds time maintained above: ? temperature (t l ) ? time (t l ) 183 c 60-150 seconds 217 c 60-150 seconds peak temperature(t p ) 240 +0/-5 c 260 +0/-5 c time within 5 c of actual peak temperature(tp) 10-30 seconds 20-40 seconds ramp down rate 6 c/second max. 6 c/second max. time 25 c to peak temperature 6 minutes max. 8 minutes max. note : all temperatures refer to topside of t he package, measured on the package body surface.
cystech electronics corp. spec. no. : c151n6 issued date : 2012.11.08 revised date : page no. : 11/11 MC7773N6 cystek product specification sot-23-6l dimension j 12 3 4 5 6 a b c d d1 d2 e f g k i l h marking: 6-lead sot-23-6l plastic surface mounted package cystek package code: n6 style: pin 1. gnd pin 2. fb pin 3. pt pin 4. sense pin 5. vdd pin 6. gate 73abc device name date code inches millimeters inches millimeters dim min. max. min. max. dim min. max. min. max. a 0.1063 0.1220 2.70 3.10 f 0.0472 ref 1.20 ref b 0.1024 0.1181 2.60 3.00 g 0 0.0059 0 0.15 c 0.0551 0.0709 1.40 1.80 h - 0.0086 - 0.22 d 0.0748 ref 1.90 ref i 0.0047 ref 0.12 ref d1 0.0374 ref 0.95 ref j 0.0146 ref 0.37 ref d2 0.0374 ref 0.95 ref k 0.0236 ref 0.60 ref e 0.0118 0.0217 0.30 0.55 l 0 10 0 10 notes : 1.controlling dimension : millimeters. 2.maximum lead thickness includes lead finish thickness, and minimum lead thickness is the minimum thickness of base material. 3.if there is any question with packing specification or packing method, please c ontact your local cystek sales office. material : ? mold compound : epoxy resin family, flammability solid burning class:ul94v-0. important notice: ? all rights are reserved. reproduction in whole or in part is prohibited without the prior written approval of cystek. ? cystek reserves the right to make changes to its products without notice. ? cystek semiconductor products are not warranted to be suitable for use in life-support applications, or systems. ? cystek assumes no liability for any consequence of customer pr oduct design, infringement of pat ents, or application assistance .

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