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n2112nkpc 20120801-s00003 no.a2104-1/16 http://onsemi.com semiconductor components industries, llc, 2013 august, 2013 lv5980mc overview lv5980mc is 1ch dcdc converter with built-in power pc h mosfet. the recommended operating range is 4.5v to 23v. the maximum current is 3a. the operating current is about 63 a, and low power consumption is achieved. features and functions ? 1ch sbd rectification dcdc converter ic with built-in power pch mosfet ? typical value of light load mode current is 63 a ? 4.5v to 23v operating input voltage range ? 100m high-side switch ? output voltage adjustable to 1.235v ? the oscillatory frequency is 370khz ? built-in ocp circuit with p-by-p method ? when p-by-p is generated continuo usly, it shifts to the hiccup operation ? external capacitor soft-start ? under voltage lock-out, thermal shutdown applications ? set top boxes ? dvd/blu-ray ? drivers and hdd ? lcd monitors and tvs ? point of load dc/dc converters ? office equipment ? pos system ? white goods application circuit example bi-cmos ic low power consumption and high efficiency step-down switching regulator orderin g numbe r : ena2104 40 30 20 10 50 60 70 80 90 1 23 57 10 23 57 100 23 57 1000 23 57 23 57 load current -- ma efficiency -- % 0 100 0.1 10000 v out = 5v v i n = 8 v v i n = 1 2 v v i n = 1 5 v efficienc y v in gnd v in lv5980mc pdr c1: grm31cb31e106k [murata] c2: c2102jb0j106m [tdk] l1: fdve1040-100m [toko] d1: sb3003ch [sanyo] sw fb ref comp ss/hiccup c1 c3 10 f 2 10 f 3 l1 10 h 1 f c7 r1 d1 r3 5v vout c2 r2 47k 1 f c6 4.7nf c5 2.2nf
lv5980mc no.a2104-2/16 specifications absolute maximum ratings at ta = 25 c parameter symbol conditions ratings unit input voltage v in max 25 v v in -sw 30 v v in -pdr 6v ref 6v ss/hiccup ref v fb ref v allowable pin voltage comp ref v allowable power dissipation pd max specified substrate *1 1.35 w operating temperature topr -40 to +85 c storage temperature tstg -55 to +150 c *1 specified substrate : 50.0mm 50.0mm 1.6mm, fiberglass epoxy printed circuit board, 4 layers note 1 : absolute maximum ratings represent the val ues which cannot be exceeded for any length of time. note 2 : even when the device is used within the range of absolute maximum ratings, as a result of continuous usage under high temperature, high current, high voltage, or drastic temperature change, the reliability of th e ic may be degraded. please contact us for the further detai ls. recommended operating conditions at ta = 25 c parameter symbol conditions ratings unit input voltage range v in 4.5 to 23 v electrical characteristics at ta = 25c, v in = 15v ratings parameter symbol conditions min typ max unit reference voltage internal reference voltage v ref 1.210 1.235 1.260 v pch drive voltage v pdr i out = 0 to -5ma v in -5.5 v in -5.0 v in -4.5 v saw wave oscillator oscillatory frequency f osc 310 370 430 khz soft start circuit soft start ? source current i ss _sc 1.2 1.8 2.4 a soft start ? sink current i ss _sk v in = 3v, ss = 0.4v 300 a uvlo circuit uvlo release voltage v uvlon fb = comp 3.3 3.7 4.1 v uvlo lock voltage v uvlof fb = comp 3.02 3.42 3.82 v error amplifier input bias current i ea _in -100 -10 na error amplifier gain g ea 100 220 380 a/v output sink current i ea _osk fb = 1.75v -30 -17 -8 a output source current i ea _osc fb = 0.75v 8 17 30 a over current limit circuit current limit peak i cl 3.5 4.7 6.2 a hiccup timer start-up cycle n cyc 15 cycle hiccup comparator threshold voltage v thic 0.15 v hiccup timer discharge current i hic 0.25 a pwm comparator maximum on-duty d max 94 % output output on resistance r on i o = 0.5a 100 m the entire device light load mode co nsumption current i sleep no switching 63 83 a thermal shutdown tsd design guarantee *2 170 c *2 : design guarantee: signifies target value in desi gn. these parameters are not tested in an independent ic. stresses exceeding maximum ratings may damage the device. maximum ratings are stress ratings only. functional operation above the recommended oper ating conditions is not implied. extended exposure to stresses above the recommended operating conditions may affect device reliabili ty.
lv5980mc no.a2104-3/16 package dimensions unit : mm (typ) 3424 specified substrate sanyo : soic8 4.9 3.9 6.0 12 8 0.835 0.375 0.2 0.42 1.27 0.175 1.75 max top bottom 2 nd /3 rd layers 0 1.0 0.5 2.0 1.5 1.35 80 0.70 60 20 40 0 100 --40 --20 pd max ? ta ambient temperature, ta -- c allowable power dissipation, pd max -- w
lv5980mc no.a2104-4/16 pin assignment pin function description pin no, pin name function 1 pdr pch mosfet gate drive voltage. the bypass capacitor is necessarily connected between this pin and v in . 2 gnd ground pin. ground pin voltage is reference voltage 3 ss/hiccup capacitor connection pin for soft start and setting re-startup cycle in hiccup mode. about 1.8ua current charges the soft start capacitor. 4 comp error amplifier output pin. the phase compensation network is c onnected between gnd pin and comp pin. thanks to current-mode control, comp pin voltage would tell you the output current amplitude. comp pin is connected internally to an init.comparator which compares with 0.9v reference. if comp pin voltage is larger than 0.9v, ic operates in ?continuous mode?. if comp pin voltage is smaller than 0.9v, ic operates in ?discontinuous mode (low consumption mode)?. 5 fb error amplifier reverse input pin. ics make its voltage keep 1.235v. output voltage is divided by external resistances and it across fb. 6 ref reference voltage. 7 v in supply voltage pin. it is observed by the uvlo function. when its voltage becomes 3.7v or more, ics startup in soft start. 8 sw high-side pch mosfet drain pin. 1 pdr 2 gnd 3 ss/hiccup 4 comp sw 8 v in 7 ref 6 fb 5 lv5980mc soic8 top view
lv5980mc no.a2104-5/16 block diagram wake-up level-shift tsd uvlo.comp ss_end.comp pwm comp pbyp.comp band-gap bias 1.235v 15pulse counter ilim logic osc s r ck q ocp.comp ref pch drive lnit.comp slope clk gnd pdr error.amp enable hiccup_sd v in comp fb sw ref pdr gnd ss/hiccup enable hiccup_sd hiccup_sd q
lv5980mc no.a2104-6/16 pin equivalent circuit pin no. pin name equivalent circuit 1 pdr v in gnd pdr 1.5m 1.3m 10k 10k 10 2 gnd v in gnd 3 ss/hiccup v in ss/hiccup gnd 10k 10k 1k 1k 4 comp v in comp gnd 1k 1k 70k 5 fb v in fb gnd 10k 1k 1k continued on next page.
lv5980mc no.a2104-7/16 continued from preceding page. pin no. pin name equivalent circuit 6 ref v in ref gnd 10 10 51k 1m 450k 7 v in v in gnd 8 sw v in sw 22m
lv5980mc no.a2104-8/16 detailed description power-save feature the lv5980mc has power-saving feature to enha nce efficiency when the load is light. by shutting down unnecessary circuits, ope rating current of the ic is minimized and high efficiency is realized. output voltage setting output voltage (v out ) is configurable by the resistance r3 between v out and fb and the r2 between fb and gnd. v out is given by the following equation (1). v out = (1 + r3 r2 ) v ref = (1 + r3 r2 ) 1.235 [v] (1) soft start soft start time (t ss ) is configurable by the capacitor (c5) be tween ss/hiccup and gnd. the setting value of t ss is given by the equation (2). t ss = c5 v ref i ss = c5 1.235 1.8 10 -6 [ms] (2) hiccup over-current protection over-current limit (i cl ) is set to 4.7a in the ic. when the peak value of inductor current is higher than 4.7a for 15 consecutive times, the protection deems it as over current and stops the ic. stop period (t hic ) is defined by the discharging time of the ss/hiccup. wh en ss/hiccup is lower than 0.15v, th e ic starts up. when ss/hiccup is higher than 0.3v and then over current is detected, the ic stops again. and when ss/hiccup is higher than 1.235v, the discharge starts again. when the protection does not det ect over-current status, th e ic starts up again. the ic stops when the peak val ue of inductor current is higher than overcurrent limit for 15 consecutive times. * the stop time defined by the discharging time of the ss/hiccup. the ic starts up when ss/hiccup is lower than 0.15v. ? the ic stops when ss/hiccup is higher than 0.3v and overcurrent is detected. ? the ic starts up again if no overcurrent is detected. i cl il ss/hiccup 1.235v 0.3v 0.15v t hic fb
lv5980mc no.a2104-9/16 design procedure inductor selection when conditions for input voltage, output voltage and ripple current are defined, the following equations (3) give inductance value. l = v in - v out i r t on (3) t on = 1 {((v in - v out ) (v out + vf)) + 1} f osc f osc : oscillatory frequency vf : forward voltage of schottky barrier diode v in : input voltage v out : output voltage ? inductor current: peak value (i rp ) current peak value (i rp ) of the inductor is given by the equation (4). i rp = i out + v in - v out 2l t on (4) make sure that rating current value of the inductor is higher than a peak value of ripple current. ? inductor current: ripple current ( ? i r ) ripple current ( ? i r ) is given by the equation (5). i r = v in - v out l t on (5) when load current (i out ) is less than 1/2 of the ripple curren t, inductor current flows discontinuously. output capacitor selection make sure to use a capacitor with low impedance for switc hing power supply because of large ripple current flows through output capacitor. this ic is a switching regulator which adopts current mode control method. therefore, you can use capacitor such as ceramic capacitor and os capacitor in which equivalent series resistance (esr) is exceedingly small. effective value is given by the equation (6) because the ripp le current (ac) that flows th rough output capacitor is saw tooth wave. i c_out = 1 2 3 v out (v in - v out ) l f osc v in [arms] (6) input capacitor selection ripple current flows through input capacitor which is higher than that of the output capacitors. therefore, caution is also required for allowable ripple current value. the effective value of the ripple current flows through input capacitor is given by the equation (7). i c_in = d (1 - d) i out [arms] (7) d = t on t = v out v in in (7), d signifies the ratio between on/off period. when the value is 0.5, the ripple current is at a maximum. make sure that the input capacitor does not exceed the allowable ripple current value given by (7). with (7), if v in =15v, v out =5v, i out =1.0a and f osc =370 khz, then i c_in value is about 0.471arms. in the board wiring from input capacitor, v in to gnd, make sure that wiring is wide enough to keep impedance low because of the current fluctuation. make sure to connect input cap acitor near output capacitor to lower voltage bound due to regeneration current.when change of load current is excessive (i out : high ? low), the power of output electric capacitor is regenerated to input capacitor. if input capacitor is small, input voltage increas es. therefore, you need to implement a large input capacitor. regeneration power changes according to the change of ou tput voltage, inductance of a coil and load current.
lv5980mc no.a2104-10/16 selection of external phase compensation component this ic adopts current mode control which allows use of ceramic capacitor with low es r and solid polymer capacitor such as os capacitor for output capacitor with simple phase compensation. therefore, you can design long-life and high quality step-down power supply circuit easily. frequency characteristics the frequency characteristic of this ic is c onstituted with the following transfer functions. (1) output resistance breeder : h r (2) voltage gain of error amplifier : g vea current gain : g mea (3) impedance of phase comp ensation external element : z c (4) current sense loop gain : g cs (5) output smoothing impedance : z o closed loop gain is obtained with the following formula (8). g = h r ? g mer ? z c ? g cs ? z o = v ref v out ? g mer ? r c + 1 sc c ? g cs ? r l 1 + sc o ? r l (8) frequency characteristics of the closed loop gain is given by pole fp1 consists of output capacitor c o and output load resistance r l , zero point fz consists of external capacitor c c of the phase compensa tion and resistance r c , and pole fp2 consists of output impedance z er of error amplifier and external capacitor of phase compensation c c as shown in formula (8). fp1, fz, fp2 are obtained with the following equations (9) to (11). fp1 = 1 2 ? c o ? r l (9) fz = 1 2 ? c c ? r c (10) fp2 = 1 2 ? z er ? c c (11) fb v ref g ver g mer r c c c z c r l c o z o comp sw clk current sence loop h r v out v in r 2 r 1 osc 1/g cs q d c r
lv5980mc no.a2104-11/16 calculation of external phase compensation constant generally, to stabilize switching regula tor, the frequency where closed loop gain is 1 (zero-cross frequency f zc ) should be 1/10 of the switching frequency (or 1/5). since the switching frequency of this ic is 370khz, the zero-cross frequency should be 37khz. based on the above condition, we obtain the following formula (12). v ref v out ? g mer ? r c + 1 sc c ? g cs ? r l 1 + sc o ? r l = 1 (12) as for zero-cross frequency, since the impe dance element of phase compensation is rc >> 1/sc c , the following equation (13) is obtained. v ref v out ? g mer ? r c ? g cs ? r l 1 + 2 ? f zc ? c o ? r l = 1 (13) phase compensation external resistance can be obtained with the following formula (14), the variation of the formula (13). since 2 ? f zc ? c o ? r l >> 1 in the equation (14), we know that the extern al resistance is independent of load resistance. r c = v out v ref ? 1 g mer ? 1 g cs ? 1 + 2 ? f zc ? c o ? r l r l (14) when output is 5v and load resistance is 5 (1a load), the resistances of pha se compensation are as follows. g cs = 2.7a/v, g mer = 220 a/v, f zc = 37khz r c = 5 1.235 1 220 10 -6 1 2.7 1 + 2 3.14 (37 10 3 ) (30 10 -6 ) 5 5 = 48.898 10 3 = 48.90 [k ] if frequency of zero point fz and pole fp1 are in the same position, they cancel out each other. therefore, only the pole frequency remains for frequency characteristics of the closed loop gain. in other words, gain decreases at -20db/dec and phase only ro tates by 90o and this allows characteristics where oscillation never occurs. fp1 = fz 1 2 ? c o ? r l ? 1 2 ? c o ? r c c c = r l ? c o r c ? 5 (30 10 -6 ) 48.9 10 3 = 3.067 10 -9 = 3.07 [nf] the above shows external compensation constant obtained through ideal equations. in reality, we need to define phase constant through testing to verify constant ic operation at all temperature range, load range and input voltage range. in the evaluation board for delivery, phase compensation constants are defined based on the above constants. the zero-cross frequency required in the actual system board, in other word, transient response is adjust ed by external compensation resistance. also, if the influence of noise is significant, use of external phase co mpensation capacitor with higher value is recommended.
lv5980mc no.a2104-12/16 caution in pattern design pattern design of the board affects the char acteristics of dc-dc converter. this ic switches high current at a high speed. therefore, if inductance element in a pattern wiring is high, it c ould be the cause of noise. make sure that the pattern of the main circuit is wide and short. (1) v in (6) (5) (3) orange : high side mosfet on red : high side mosfet off l1 d1 c3 cout cin (4) (2) v out gnd (1) pattern design of the input capacitor connect a capacitor near the ic for noise reduction between v in and the gnd. the change of current is at the largest in the pattern between an input capacitor and v in as well as between gnd and an in put capacitor among all the main circuits. hence make sure that the pattern is as fat and short as possible. (2) pattern design of an inductor and the output capacitor high electric current flows into the choke coil and the output capacitor. therefore this pattern should also be as fat and short as possible. (3) pattern design with current channel into consideration make sure that when high side mosfet is on (red arro w) and off (orange arrow), the two current channels runs through the same channel and an area is minimized. (4) pattern design of the capacitor between v in -pdr make sure that the pattern of the capacitor between v in and pdr is as short as possible. (5) pattern design of the small signal gnd the gnd of the small signal should be separated from the power gnd. (6) pattern design of the fb-out line wire the line shown in red between fb and ou t to the output capacitor as near as possible. fig: fb-out line fb out
lv5980mc no.a2104-13/16 typical performance characteristics application curves at ta = 25 c operation waveforms (circuit from typical application, ta = 25 c, v in = 15v, v out = 5v) efficiency 10 20 30 40 50 60 70 80 90 20 30 40 50 60 70 80 90 20 30 40 50 60 70 80 90 100 10 20 30 40 50 60 70 80 90 100 0.1 1 23 57 10 23 57 100 23 57 1000 23 57 23 57 1 23 57 10 23 57 100 23 57 1000 23 57 23 57 10000 1 23 57 10 23 57 100 23 57 1000 23 57 23 57 1 23 57 10 23 57 100 23 57 1000 23 57 23 57 10000 load current -- ma efficiency efficiency -- % 0.1 load current -- ma efficiency efficiency -- % 10 100 0.1 10000 load current -- ma efficiency efficiency -- % 10 100 0.1 10000 light load mode output voltage load current -- ma efficiency -- % v out = 1.235v v out = 1.8v v out = 3.3v v out = 5v v i n = 5 v 1 5 v 1 2 v 8v 8v v i n = 5 v v i n = 8 v 1 5 v 1 5 v 1 2 v v i n = 5 v 1 5 v 1 2 v i out = 10ma 10 s/div i out = 10ma 10 s/div v sw 5v/div i l 0.5a/div v out 20mv/div i l 0.5a/div 8v 1 2 v
lv5980mc no.a2104-14/16 i out = 2a 2 s/div i out = 2a 2 s/div v sw 5v/div i l 1a/div v out 20mv/div i l 1a/div discontinious current mode output voltage continious current mode output voltage load transient response over current protection soft start and shutdown i out = 200ma 2 s/div i out = 200ma 2 s/div v sw 5v/div i l 0.5a/div v out 20mv/div i l 0.5a/div i out = 0.5 q 2.5a, slew rate = 100 a 500 s/div i out = 2a 2ms/div v out 0.2v/div i out 2a/div v out 2v/div v ss/hiccup 2v/div v in 20v/div out - gnd short 20ms/div v ss/hiccup 5v/div v sw 20v/div i out 5a/div v out 5v/div
lv5980mc no.a2104-15/16 characterization curves at ta = 25 c, v in = 15v light load mode consumption current 0 10 20 30 40 50 60 70 80 20 40 60 80 100 120 140 4.3 4.4 4.5 4.6 4.7 4.8 4.9 90 1.21 1.22 1.23 1.24 1.25 1.26 --50 --25 0 25 50 75 100 125 --25 0 25 50 75 100 125 --25 0 25 50 75 100 125 --25 0 25 50 75 100 125 --25 0 25 50 75 100 125 --25 0 25 50 75 100 125 --25 0 25 50 75 100 125 --25 0 25 50 75 100 125 150 150 temperature -- c internal reference voltage internal reference voltage -- v -- 50 temperature -- c output on resistance output on resistance -- m 0 160 --50 150 temperature -- c current limit peak current limit peak -- a 4.2 5 --50 150 temperature -- c input current -- a 310 320 330 340 350 360 370 390 380 3.3 3.4 3.5 3.6 3.7 temperature -- c oscillatory frequency oscillatory frequency -- khz 300 400 --50 150 temperature -- c uvlo uvlo voltage -- v 3.2 3.8 --50 150 1.6 1.7 1.8 1.9 0.19 0.21 0.23 0.25 0.27 0.29 0.31 temperature -- c soft start source current soft start source current -- a 1.5 2 --50 150 temperature -- c hiccup timer discharge current hiccup timer charge current -- a 0.17 0.33 --50 150 uvlo release voltage uvlo lock voltage
lv5980mc ps no.a2104-16/16 recommended foot pattern: soic8 soldering footprint* 1.270 0.050 0.6 0.024 4.0 0.155 7.0 0.275 1.52 0.060 scale 6:1 mm inches ( ( *for additional information on our pd-free strategy and soldering details, please download the on semiconductor soldering and mounting techniques reference manual, solderrm/d. on semiconductor and the on logo are registered trademarks of semiconductor components industries, llc (scillc). scillc owns the rights to a number of patents, trademarks, copyrights, trade secrets, and other intellectual property. a listing of scillc?s product/patent coverage may be accessed at www.onsemi.com/site/pdf/patent-marking.pdf. scillc reserves the right to make changes without further notice to any products herein. scillc mak es no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does scillc assume any liability ar ising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequentia l or incidental damages. ?typical? parameters which may be provided in scillc data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. all operating parameters, including ?typicals? must be validated for each customer application by customer?s techn ical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorize d for use as components in systems intended for surgical implant into the body, or other applications intended to support or sustain life, or for any other appli cation in which the failure of the scillc product could create a situation where personal injury or death may occur. should buyer purchase or use scillc products for any such unintended or unauthorized application, buyer shall indemnify and hold scillc and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of persona l injury or death associated with such unintended or unauthorized use, even if such claim alleges that scillc was negligent regarding the design or manufacture o fthe part. scillc is an equal opportunity/affirmative action employer. this literature is subject to all applicable copyright laws a nd is not for resale in any manner.

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