38 ics 1-1-3 dc/dc converter ics absolute maximum ratings unit v w c c c/w c/w ratings 53 1 +125 ?0 to +125 28 100 symbol v in p d *1 t j t stg j-c j-a parameter dc input voltage power dissipation junction temperature storage temperature thermal resistance (junction to case) thermal resistance (junction to ambient air) parameter dc input voltage range output voltage range output current range *2 operating junction temperature range operating temperature range symbol v in v o i o t jop t op ratings si-8010gl (8 or v o +3) *1 to 50 1 to 14 0.02 to 1.5 *2 ?0 to +125 ?0 to +125 *1: the minimum value of an input voltage range is the higher of either 8v or v o +3v. *2: please be sure to let the output current run more than 20 ma. when using by less than 20 ma, there is a possibility that the output voltage becomes unstable. recommended operating conditions *1: limited by thermal protection. electrical characteristics unit v % kh z mv mv mv/ c a ma a v a parameter reference voltage efficiency oscillation frequency line regulation load regulation t emperature coefficient of reference voltage overcurrent protection starting current quiescent circuit current circuit current at output off ce/ss * low level voltage t erminal t erminal outflow current at low voltage symbol v ref conditions eff conditions f osc conditions ? v oline conditions ? v oload conditions ? v ref / ? t a i s conditions i q conditions i q ( off ) conditions v ssl i ssl conditions (t a =25 c) *: pin 2 is the ce/ss pin. soft start at power on can be performed with a capacitor connected to this pin.the output can also be turned on/off with this pin. the output is stopped by setting the voltage of this pin to v ssl or lower. ce/ss-pin voltage can be changed with an open-collector drive circuit of a transistor. when using both the soft-start and on/off functions together, the discharge current from c 4 flows into the on/off control transistor. therefore, limit the current securely to protect the transistor if c 3 capacitance is large. the ce/ss pin is pulled up to the power supply in the ic, so applying the external voltage is prohibited. features dip 8 pin package output current: 1.5a high efficiency: 86% (at v in = 20v, l o = 1a, v o = 5v) capable of downsize a choke-coil due to ic's high switching frequency (250khz). (com- pared with conventional sanken devices) the output-voltage-variable type can vary its output voltage from 1v to 14v because of its low reference voltage (vref) of 1v. ? ide input voltage range (8 to 50v) output on/off available built-in overcurrent protection and thermal protection circuits ratings si-8010gl (variable type) min. typ. max. 0.97 1.00 1.03 v in =12v, i o =1a 86 v in =20v, i o =1a, v o =5v 250 v in =12v, i o =1a 20 40 v in =10 to 30v, i o =1a 10 30 v in =12v, i o =0.1 to 1.5a 0.5 1.6 v in =12v 7 v in =12v, i o =0a 400 v in =12v, v on/off =0.3v 0.5 50 v ssl =0v compact, separate excitation step-down switching mode si-8000gl series applications onboard local power supplies ? a equipment for stabilization of the secondary-side output voltage of switching power supplies si-8000gl si-8000gl ce/ss 2 ce/ss 2 ce/ss c4 c4 2 v o. on/off soft start soft start +v o. on/off si-8000gl unit v v a c c
39 ics si-8000gl series external dimensions (dip8) (unit: mm) block diagram ce/ss uvlo ocp p.reg osc pwm logic ce/ss tsd reg comp gnd 1v boot reg drive bs sw out v ref v in + - + - amp pin assignment 1. gnd 2. ce/ss 3. reg 4. sw out 5. v in 6. b.s 7. c omp 8. v ref plastic mold package type flammability: ul 94v-0 product mass: approx. 0.49 g si-8010gl 7 8 2 1 5 4 6 3 9.4 0.3 0.5 0.1 0 to 15 6.5 0.2 3.4 0.1 3.3 0.2 4.2 0.3 7.5 0.5 1.0 +0.3 - 0.05 1.5 +0.3 - 0.05 0.25 +0.1 - 0.05 2.54 7.6 0.25 m 0.89 typ 2 1.8 1.6 1.4 1.2 1 0.8 0.6 0.4 0.2 0 ?5 0 25 50 75 100 125 power dissipation p d (w) ambient temperature t a ( c) j-a:100 c/w t a -p d characteristics note 1: the efficiency depends on the input volt- age and the output current. therefore , ob- tain the value from the efficiency graph and substitute the percentage in the formula above. note 2: thermal design for d 1 must be considered separately. v o : output voltage v in : input voltage i o : output current ? : efficiency v f : diode d 1 forward voltage rk16?.4v(i o =1a) t ypical connection diagram c1: 220 f/63v c2: 470 f/25v c3: 0.1 f c4: 1000pf c5: 0.1 f c6: 0.047 f c7: 0.1 f diode d 1 be sure to use a schottky-barrier diode as d 1 . if other diodes like fast recovery diodes are used, ic may be destroyed because of the reverse voltage generated by the recovery voltage or on voltage. choke coil l 1 if the winding resistance of the choke coil is too high, the efficiency may drop below the rated value. as the overcurrent protection starting current is approx. 2.5 a, take care concerning heat radiation from the choke coil cause d by magnetic saturation due to overload or short-circuited load. capacitor c 1 , c 2 ? s large ripple currents flow through c 1 and c 2 , use high-frequency and low-impedance capacitors aiming for switching-mode-power-supply use. especially when the impedance of c 2 is high, the switching waveform may become abnormal at low temperatures. for c 2 , do not use a capacitor with an extremely low equivalent series resistance (esr) such as an os capacitor or a tantalum capacitor, which may cause an abnormal oscillation. resistors r 2 , r 3 ?r 2 and r 3 are the resistors to set the output voltage. set their values so that i ref becomes approx. 2 ma. obtain r 2 and r 3 values by the following formula above. * to create the optimum operating conditions, place the components as close as possible to each other. si-8010gl reg ce/ss 3 2 v in sw out v ref v in gnd v 0 gnd 5 c5 comp 7 6 c6 c3 d1 l1 r2 r3 i ref gnd b.s si-8010gl 1 8 4 r1 c4 c1 c7 + c2 c8 + c8: 0.1 f r1: 47 ? l1: 47 h d1: rk16 (sanken) p d =v o ?i o 100 ? ? f ?i o 1 v o ? v in r2= (v out ? ref ) = (v out ?) ( ? ), r3 = v ref = 1 500( ? ) i ref 2 10 ? i ref 2 10 ? = . .
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