technical note automotive body power management lsi design information ldo regulator rohm co.,ltd tentative bd357xfp/hfp series z description bd357xfp/hfp series regulators feature a high 50 v with stand-voltage and are suitable for use with onboard vehicle microcontrollers. they offer the output current of 500 ma while limiting the quiescent current to 30 a (typ).with these devices, a ceramic capacitor can be selected at the output for stable operation, the output tolerance is within 2% over the wide ambient temperature range (-40 to 125 ), and the short circuit protection is fold ed-type to minimize generation of heat during malfunction. these devices are developed to offer mo st robust power-supply design under the harsh automotive environment. the bd357xfp/hfp series provide ideal solutions to lower the current consumption as well as to simplify the use with battery direct-coupled systems. z features 1) ultra-low quiescent current: 30 a (typ.) 2) low-saturation voltage type p- channel dmos output transistors 3) high output voltage precision: 2% iomax = 500 ma 4) low-esr ceramic capacitors can be used as output capacitors. 5) vcc power supply voltage = 50 v 6) built-in overcurrent protection circuit and thermal shutdown circuit 7) to252-3,5 hrp-5 package z applications ? onboard vehicle devices (body-control, car stereos, satellite navigat ion systems, etc.) z product line bd3570fp/hfp bd3571fp/hfp bd3572fp/hfp b d3573fp/hfp bd3574fp/hfp bd3575fp/hfp output voltage 3.3v 5.0 v va riable 3.3v 5.0 v variable sw function package fp:to252-3,to252-5 hfp:hrp5 z absolute maximum ratings (t a =25c) parameter symbol limit unit supply voltage v cc 50 1 v switch supply voltage v sw 50 2 v output current i o 500 ma 1.2 (to252-3) 3 1.3 (to252-5) 4 power dissipation pd 1.6 (hrp5) 5 w operating tem perature range t opr -40 to +125 c storage temperature range t stg -55 to +150 c maximum junction temperature t jmax 150 c 1 not to exceed pd and aso. 2 for on/off sw regulator only 3 to252-3: reduced by 9.6 mw/c over 25 c , when mounted on a glass epoxy board (70 mm 70 mm 1.6 mm). 4 to252-5: reduced by 10.4 mw/c over 25 c, when mounted on a glass epoxy board (70 mm 70 mm 1.6 mm). 5 hrp-5: reduced by 12.8 mw/c over 25 c , when mounted on a glass epoxy board (70 mm 70 mm 1.6 mm). 2007. sep.
tentative rohm co. , ltd z operating conditions parameter symbol min. max. unit bd3570,3572,3573,3575fp/hfp v cc 4.5 6 36.0 v input voltage bd3571,3574fp/hfp v cc 5.5 6 36.0 v output current i o 500 ma variable output voltage range v o 2.8 12 v 6 please consider that the output voltage would be dropped (dropout voltage) according to the output current. z electrical characteristics unless otherwise specified, t a =-40 to125c, v cc =13.2 v, sw=3v 7, v o settings is 5v 8 limit parameter symbol min. typ. max. unit conditions shut down current lshut 10 a sw=gnd bias current lb 30 50 a i o =0ma output voltage v o v o 0.98 v o v o 1.02 v i o =200ma, v o :please refer to product line. adj terminal voltage 8 vadj 1.235 1.260 1.285 v i o =200ma output current i o 0.5 a dropout voltage vd 0.25 0.48 v v cc =4.75v,l o =200ma 9 ripple rejection r.r. 45 55 db f=120hz,ein=1v rms ,i o =100ma line regulation reg.i 10 30 mv v ccd 10Qv cc Q25v i o = 0 ma load regulation reg.l 20 40 mv 0 aQi o Q200a swith threshold voltage h swh 2.0 v i o =0 ma swith threshold voltage l swl 0.5 v i o =0 ma swith bias current swi 22 60 a sw=5v,l o =0ma 7 bd3573,3574,3575fp/hfp only 8 bd3572,3575fp/hfp only 9 bd3571,3572,3574,3575fp/hfp only 10 bd3570,3573fp/hfp :v ccd =5.5v bd3571,3572,3574,3575fp/hfp :v ccd =6.5v 2/8
3/8 fig. 1 total supply current z reference data: bd3574hfp unless otherwise specified, t a =25c 0 10 20 30 40 50 0 5 10 15 20 25 supply voltage: v dd [v] circuit current: i cc [ a] t a =25 t a =125 t a =-40 fig. 6 output voltage vs sw input voltage 0 1 2 3 4 5 6 00.511.52 supply voltage: v sw [v] output voltage: v o [v] t a =25 t a =-40 t a =125 fig. 9 output voltage vs temperature 4.5 4.75 5 5.25 5.5 - 40 0 40 80 120 ambient temperature: t a [ ] output voltage: v o [v] fig. 7 total supply current classified by load 0 20 40 60 80 100 0 100 200 300 400 500 output current: i o [ma] circuit current: i cc [ a] fig. 8 thermal shutdown circuit 0 1 2 3 4 5 6 100 120 140 160 180 200 ambient temperature: t a [ ] output voltage: v o [v] fig. 10 sw bias current 0 30 60 90 120 0 5 10 15 20 25 supply voltage: v sw [v] sw bias current: i sw [ a] t a =-40 t a =25 t a =125 fig. 11 dropout voltage vs temperature 0 0.5 1 1.5 2 -40 0 40 80 120 ambient temperature: t a [ ] dropout voltage: vd [v] fig. 12 total supply current t e mperature 0 10 20 30 40 50 -40 0 40 80 120 ambient temperature: t a [ ] circuit current: i cc [ a] fig. 2 output voltage vs power supply voltage 0 1 2 3 4 5 6 0 5 10 15 20 25 supply voltage: v cc [v] output voltage: v o [v] 0 1 2 3 4 5 6 0 500 1000 1500 2000 output current: i o [ma] output voltage: v o [v] t a =125 t a =-40 t a =25 fig. 3 output voltage vs load t a =-40 t a =25 t a =125 0 10 20 30 40 50 60 70 10 100 1000 10000 100000 1000000 frequency: f [hz] ripple rejection: r.r. [db] fig. 4 dropout voltage 0 1 2 3 0 100 200 300 400 500 output current: i o [ma] dropout voltage: vd[v] t a =125 t a =-40 t a =25 t a =125 t a =25 t a =-40 tentative rohm co. , ltd fig. 5 ripple rejection
tentative rohm co. , ltd z block diagram gnd vcc vref ocp tsd vo fin 1 n.c. 2 3 cin fig.13 to252-3 cin 0.33f 1000 f co0.1 f 1000f co fig.14 to252-5 vo co adj (n.c. 1) ) gnd vcc vref ocp tsd fin 1 5 cin 4 1 2 2 sw gnd vref ocp tsd vo 5 co 4 fin sw 2 3 n.c. adj (n.c. 1) ) 1 2 1 for fixed voltage regulator only 2 for adjustable voltage regulator only fig.15 hrp-5 vcc 1 cin 3 z i/o cirouit diagram (all resistance values are typical.) fig.16 2pin[sw] sw 210k 1k 200k fig.17 5pin[v o ] bd3570,3571,3573,3574 vcc vo 1992k: bd3570, bd3573 3706k: bd3571, bd3574 1250k fig.18 4.5pin[adj,v o ] bd3572,bd3575 vcc vo 150 z pin assignments 1 23 fin fig. 19 pin no. pin name function 1 v cc power supply pin 2 n.c. n.c. pin 3 v o voltage output pin fin gnd gnd pin ? to252-3 pin no. pin name function 1 v cc power supply pin 2 sw n.c. fin 1 4/8 ? to252-5 v o on/off function pin n.c. pin(bd3572fp only) 3 n.c. n.c. pin 4 n.c. adj n.c. pin output voltage setting pin(bd3572,3575fp only) 5 v o voltage output pin fin gnd gnd pin 23 4 5 fig.20 pin no. pin name function 1 v cc power supply pin 2 sw n.c. fig. 21 12 3 45 fin v o on/off function pin (bd3573,3574,3575hfp only) n.c. pin 3 gnd gnd pin 4 n.c. adj ? hrp-5 n.c. pin output voltage setting pin(bd3572,3575hfp only) 5 v o voltage output pin fin gnd gnd pin
tentative rohm co. , ltd z output voltage adjustment adj vo r2 r1 to set the output voltage insert pull-down resistor r1 between the adj and gnd pins, and pull-up resistor r2 between the v o and adj pins. vo = vadj (r1+r2) / r1 [v] vadj=1.26v(typ.) fig.22 the recommerided connection resistor for the adj-gnd is 30k 150k . z setting of heat to252-3 to252-5 hrp-5 5/8 0 0.4 1.2 w 0 0.8 1.2 1.6 2.0 25 50 75 100 125 150 ic mounted on a rohm standard board substrate size: 70 mm 70 mm 1.6 mm ja = 104.2 (c/w) a mbient temperature: t a [c] power dissipation: pd [w] 0 0.4 1.6 w 0 0.8 1.2 1.6 2.0 25 50 75 100 125 150 ic mounted on a rohm standard board substrate size: 70 mm 70 mm 1.6 mm ja = 78.1 (c/w) a mbient temperature: t a [c] power dissipation: pd [w] 0 0.4 1.3w 0 0.8 1.2 1.6 2.0 25 50 75 100 125 150 a mbient temperature: t a [ ] power dissipation: pd [w] ic mounted on a rohm standard board substrate size: 70 mm 70 mm 1.6 mm ja = 96.2 (c/w) fig. 23 fig. 24 fig. 25 refer to the heat mitigation characteri stics illustrated in figs. 17 and 18 when us ing the ic in an environment where t a R 25c. the characteristics of the ic are greatly influenced by the operating temperature. if t he temperature is in excess of the maxim um junction temperature t jmax , the elements of the ic may be deteriorated or damaged. it is necessary to give sufficient consideration to the heat of t he ic in view of two points, i.e., the protec tion of the ic from instantaneous damage and the maintenance of the reliability of the ic in long-time operation. in order to protect the ic from thermal des truction, it is necessary to operate the ic not in excess of the maximum junction temperature t jmax . fig. 17 illustrates the power dissipation/heat mitigatio n characteristics for the to252 package. operate the ic within the power dissipation pd. the following met hod is used to calculate the power consumption p c (w). vcc : input voltage p c =(v cc -v o )i o +v cc i cc vo : output voltage power dissipation pd Qp c io : load current icc : total supply current the load current i o is obtained to operate the ic within the power dissipation. (for more information about i cc , see page 12.) v cc -v o io Q pd-v cc i cc the maximum load current i omax for the applied voltage v cc can be calculated during t he thermal design process. ? calculation example example: bd3571fp v cc = 12 v and v o = 5 v at t a = 85c ja =104.2 /w -9.6maw/ 25 =1.2w85 =0.624w i o Q 0.624-12 i cc 12-5 i o Q 89ma (i cc =30 a) make a thermal calculation in considerati on of the above so that the whole operating temperature range will be within the power dissipation. the power consumption pc of the ic in the event of shorting (i.e., if the v o and gnd pins are shorted) will be obtained from the following equation. pc=v cc (i cc +ishort) ishort = short current
tentative rohm co. , ltd z peripheral settings for pins and precautions 1) v cc pins insert capacitors with a capacitance of 0.33 f to 1000 f between the v cc and gnd pins. the capacitance varies with the application. be sure to design the capacitance with a sufficient margin. 2) capacitors for stopping oscillation for output pins capacitors for stopping oscillation must be placed between each output pin and the gnd pin. use a capacitor within a capacitance range between 0.1 f and 1000 f. since oscillation does not occur even for esr values from 0.001 to 100 , a ceramic capacitor can be used. abrupt input voltage and load fluctuations can affect output voltages. output capacitor capacitance values should be determined afte r sufficient testing of the actual application. z operation notes 1) absolute maximum ratings use of the ic in excess of absolute maximum ratings su ch as the applied voltage or oper ating temperature range may result in ic damage. assumptions should not be made regard ing the state of the ic (shor t mode or open mode) when such damage is suffered. a physical safety measure such as a fuse should be implemented when use of the ic in a special mode where the absolute maximum rati ngs may be exceeded is anticipated. 2) gnd potential ensure a minimum gnd pin potential in all operating conditions. 3) setting of heat use a thermal design that allows for a sufficient margin in li ght of the power dissipation (pd) in actual operating conditions. 4) pin short and mistake fitting use caution when orienting and positioning the ic for mounting on printed circuit boards. improper mounting may result in damage to the ic. shorts between output pins or between output pins and the powe r supply and gnd pins caused by the presence of a foreign object may result in damage to the ic. 5) actions in strong magnetic field use caution when using the ic in the pr esence of a strong magnetic field as doing so may cause the ic to malfunction. 6) testing on application boards when testing the ic on an application board, connecting a capacito r to a pin with low impedance subjects the ic to stress. always discharge capacitors after each process or step. be sure to turn power off when mounting or dismounting jigs at the inspection stage. furthermore, for counter measures against static electricity, ground the equipment at the assembling stage and pay utmost attention at the time of transportation or storing the product. 7) this monolithic ic contains p+ isolation and p substrate layers between adjacent el ements in order to keep them isolated. pn junction is formed by the p layer and the n layer of each elem ent, and a variety of parasitic elements will be constituted. for example, when a resistor and transistor ar e connected to pins as shown in fig. 19, the p/n junction functions as a parasitic diode when gnd pin a for the resistor or gnd pin b for the transistor (npn). similarly, when gnd pin b for the transistor (npn), the parasiti c diode described above combines with the n layer of other adjacent elements to operate as a parasitic npn transistor. the formation of parasitic elements as a result of the relationships of the potentials of different pins is an inevitable resul t of the ic's architecture. the operation of parasitic elements c an cause interference with circuit operation as well as ic malfunction and damage. for these reasons, it is necessary to use caution so that the ic is not used in a way that will trigger the operation of parasitic elements, such as by the application of voltages lower than the gnd (p substrate) voltage to input pins. 6/8 gnd n p nn p+ p+ parasitic elemen t or transistor p (pin b ) c b e transistor (npn) (pin a) gnd n p n n p+ p+ resistor parasitic element p parasitic elements (pin a) parasitic element o r transistor (pin b ) gnd c b e fig. 26 example of a simple monolithic ic architecture
tentative rohm co. , ltd 8) ground wiring patterns when using both small signal and large current gnd patterns, it is recommended to isolate the two ground patterns, placing a single ground point at the application's reference poi nt so that the pattern wiring resistance and voltage variations caused by large currents do not cause vari ations in the small signal ground volt age. be careful not to change the gnd wiring pattern of any external parts, either. 9) sw pin do not apply the voltage to sw pin when the v cc is not applied. and when the v cc is applied, the voltage of sw pin must not exceed v cc . 10) thermal shutdown circuit (tsd) this ic incorporates a built-in thermal shutdown circuit for t he protection from thermal destru ction. the ic should be used within the specified power dissipation range. however, in t he event that the ic continues to be operated in excess of its power dissipation limits, the attendant rise in the chip's temperature t j will trigger the thermal shutdown circuit to turn off all output power elements. the circ uit automatically resets onc e the chip's temperature t j drops. the thermal shutdown circuit operates if the ic is under conditions in expre ss of the absolute maximum ratings. never design sets on the premise of using the thermal shutdown circuit. (see fig. 8) 11) overcurrent protection circuit (ocp) the ic incorporates a built-in overcurrent protection circuit that operates according to the output current capacity. this circuit serves to protect the ic from damage when the load is shorted. the protection circuit is designed to limit current flow by not latching in the event of a large and instantaneous current flow originating from a large capacitor or other component. these protection circuits are effective in preventing damage due to sudden and unexpected accidents. however, the ic should not be used in applications characterized by the continu ous operation or transitioning of the protection circuits. at the time of thermal designing, keep in mi nd that the current capability has negativ e characteristics to temperatures. (see fig. 3) z selecting a model name when ordering 5 3 4 p f 7 h d b t r taping e2: reel-wound embossed taping(to252-3,5) tr:reel-wound embossed toping(hrp5) packaging specifications fp to252-3,5 hfp hrp-5 part number 35703.3v output no include sw 35715.0v output no include sw rohn model name 3572variable output no include sw 35733.3v output include sw 35745.0v output include sw 3575variable output include sw 7/8
8/8 < tape and reel information > to252-3,5 embossed carrier tape e2 the direction is the 1pin of produc t is at the lower left when you hold reel on the left hand and you pull out the tape on the right hand tape quantity 2000 p cs direction of feed when you or d e r , please or der in times the amount of p a ckage q uantit y . reel direction of feed pin x x x x x x x x x x x x x x x x x x x x x x x x t o 252-3 < dimension > (unit:mm) 6.5 0.2 c0.5 2 13 0.8 0.65 0.65 2.3 0.2 2.3 0.2 0.5 0.1 1.5 2.5 9.5 0.5 2.3 0.2 0.5 0.1 5.1 + 0.2 ? 0.1 5.5 0.2 1.5 0.2 0.75 1.0 0.2 fin t o 252-5 < dimension > (unit:mm) hrp-5 tent a t ive rohm co. , lt d < dimension > (unit:mm) reel direction of feed pin when y ou order , please order in times the amount of p a ckage quantity . t ape and reel information hrp5 embossed carrier t ape tr the direction is the 1pin of produc t is at the low e r lef t w hen y ou hold r eel on the lef t hand and y ou pull out the t a pe on the right h and t ape quantity direction of feed 2000 p cs s s ?? . " 9
go
5 4 3 2 1 1.905 0.1 0.835 0.2 1.523 0.15 10.54 0.13 ? 0.05 + 0.1 0.27 4.5 (5.59) 8.82 0.1 9.395 0.125 0.08 0.73 0.1 1.72 0.08 0.05 (7.49) 8.0 0.13 1.017 0.2 1.2575 ? 4.5 + 5.5
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