dual switching diode maximum ratings (t a = 25 c) rating symbol max unit reverse voltage v r 70 vdc forward current i f 200 madc peak forward surge current i fm(surge) 500 madc thermal characteristics characteristic symbol max unit total device dissipation fr5 board (1) t a = 25 c derate above 25 c p d 200 1.6 mw mw/ c thermal resistance, junction to ambient r ja 0.625 c/w total device dissipation alumina substrate (2) t a = 25 c derate above 25 c p d 300 2.4 mw mw/ c thermal resistance, junction to ambient r ja 417 c/w junction and storage temperature t j , t stg 55 to +150 c device marking baw56wt1 = a1 electrical characteristics (t a = 25 c unless otherwise noted) characteristic symbol min max unit off characteristics reverse breakdown voltage (i (br) = 100 m adc) v (br) 70 e vdc reverse voltage leakage current (v r = 25 vdc, t j = 150 c) (v r = 70 vdc) (v r = 70 vdc, t j = 150 c) i r e e e 30 2.5 50 m adc diode capacitance (v r = 0, f = 1.0 mhz) c d e 2.0 pf forward voltage (i f = 1.0 madc) (i f = 10 madc) (i f = 60 madc) (i f = 150 madc) v f e e e e 715 855 1000 1250 mvdc reverse recovery time (i f = i r = 10 madc, r l = 100 w , i r(rec) = 1.0 madc) (figure 1) t rr e 6.0 ns 1. fr5 = 1.0 0.75 0.062 in. 2. alumina = 0.4 0.3 0.024 in. 99.5% alumina. preferred devices are on semiconductor recommended choices for future use and best overall value. on semiconductor ? semiconductor components industries, llc, 2001 march, 2001 rev. 1 1 publication order number: baw56wt1/d baw56wt1 on semiconductor preferred device case 41904, style 4 sc70/sot323 1 2 3 3 anode cathode 1 2
baw56wt1 http://onsemi.com 2 notes: 1. a 2.0 k w variable resistor adjusted for a forward current (i f ) of 10 ma. notes: 2. input pulse is adjusted so i r(peak) is equal to 10 ma. notes: 3. t p ? t rr +10 v 2.0 k 820 w 0.1 m f dut v r 100 m h 0.1 m f 50 w output pulse generator 50 w input sampling oscilloscope t r t p t 10% 90% i f i r t rr t i r(rec) = 1.0 ma output pulse (i f = i r = 10 ma; measured at i r(rec) = 1.0 ma) i f input signal figure 1. recovery time equivalent test circuit 100 0.2 0.4 v f , forward voltage (volts) 0.6 0.8 1.0 1.2 10 1.0 0.1 t a = 85 c 10 0 v r , reverse voltage (volts) 1.0 0.1 0.01 0.001 10 20 30 40 50 1.75 0 v r , reverse voltage (volts) 1.5 1.25 1.0 0.75 c d , diode capacitance (pf) 246 8 i f , forward current (ma) figure 2. forward voltage figure 3. leakage current figure 4. capacitance t a = -40 c t a = 25 c t a = 150 c t a = 125 c t a = 85 c t a = 55 c t a = 25 c i r , reverse current ( m a)
baw56wt1 http://onsemi.com 3 minimum recommended footprint for surface mounted applications surface mount board layout is a critical portion of the total design. the footprint for the semiconductor packages must be the correct size to insure proper solder connection interface between the board and the package. with the correct pad geometry, the packages will self align when subjected to a solder reflow process. mm inches 0.035 0.9 0.075 0.7 1.9 0.028 0.65 0.025 0.65 0.025 sc-70/sot-323 power dissipation the power dissipation of the sc-70/sot-323 is a function of the collector pad size. this can vary from the minimum pad size for soldering to the pad size given for maximum power dissipation. power dissipation for a surface mount device is determined by t j(max) , the maximum rated junction temperature of the die, r q ja , the thermal resistance from the device junction to ambient; and the operating temperature, t a . using the values provided on the data sheet, p d can be calculated as follows. p d = t j(max) t a r q ja the values for the equation are found in the maximum ratings table on the data sheet. substituting these values into the equation for an ambient temperature t a of 25 c, one can calculate the power dissipation of the device which in this case is 200 milliwatts. p d = 150 c 25 c 0.625 c/w = 200 milliwatts the 0.625 c/w assumes the use of the recommended footprint on a glass epoxy printed circuit board to achieve a power dissipation of 200 milliwatts. another alternative would be to use a ceramic substrate or an aluminum core board such as thermal clad ? . using a board material such as thermal clad, a power dissipation of 300 milliwatts can be achieved using the same footprint. soldering precautions the melting temperature of solder is higher than the rated temperature of the device. when the entire device is heated to a high temperature, failure to complete soldering within a short time could result in device failure. therefore, the following items should always be observed in order to minimize the thermal stress to which the devices are subjected. ? always preheat the device. ? the delta temperature between the preheat and soldering should be 100 c or less.* ? when preheating and soldering, the temperature of the leads and the case must not exceed the maximum temperature ratings as shown on the data sheet. when using infrared heating with the reflow soldering method, the difference should be a maximum of 10 c. ? the soldering temperature and time should not exceed 260 c for more than 10 seconds. ? when shifting from preheating to soldering, the maximum temperature gradient should be 5 c or less. ? after soldering has been completed, the device should be allowed to cool naturally for at least three minutes. gradual cooling should be used as the use of forced cooling will increase the temperature gradient and result in latent failure due to mechanical stress. ? mechanical stress or shock should not be applied during cooling * soldering a device without preheating can cause excessive thermal shock and stress which can result in damage to the device.
baw56wt1 http://onsemi.com 4 solder stencil guidelines prior to placing surface mount components onto a printed circuit board, solder paste must be applied to the pads. a solder stencil is required to screen the optimum amount of solder paste onto the footprint. the stencil is made of brass or stainless steel with a typical thickness of 0.008 inches. the stencil opening size for the surface mounted package should be the same as the pad size on the printed circuit board, i.e., a 1:1 registration. typical solder heating profile for any given circuit board, there will be a group of control settings that will give the desired heat pattern. the operator must set temperatures for several heating zones, and a figure for belt speed. taken together, these control settings make up a heating aprofileo for that particular circuit board. on machines controlled by a computer, the computer remembers these profiles from one operating session to the next. figure 5 shows a typical heating profile for use when soldering a surface mount device to a printed circuit board. this profile will vary among soldering systems but it is a good starting point. factors that can af fect the profile include the type of soldering system in use, density and types of components on the board, type of solder used, and the type of board or substrate material being used. this profile shows temperature versus time. the line on the graph shows the actual temperature that might be experienced on the surface of a test board at or near a central solder joint. the two profiles are based on a high density and a low density board. the vitronics smd310 convection/infrared reflow soldering system was used to generate this profile. the type of solder used was 62/36/2 tin lead silver with a melting point between 177189 c. when this type of furnace is used for solder reflow work, the circuit boards and solder joints tend to heat first. the components on the board are then heated by conduction. the circuit board, because it has a large surface area, absorbs the thermal energy more ef ficiently, then distributes this energy to the components. because of this effect, the main body of a component may be up to 30 degrees cooler than the adjacent solder joints. step 1 preheat zone 1 ramp" step 2 vent soak" step 3 heating zones 2 & 5 ramp" step 4 heating zones 3 & 6 soak" step 5 heating zones 4 & 7 spike" step 6 vent step 7 cooling 200 c 150 c 100 c 50 c time (3 to 7 minutes total) t max solder is liquid for 40 to 80 seconds (depending on mass of assembly) 205 to 219 c peak at solder joint desired curve for low mass assemblies 100 c 150 c 160 c 140 c figure 5. typical solder heating profile desired curve for high mass assemblies 170 c
baw56wt1 http://onsemi.com 5 package dimensions case 41904 issue l sc70 (sot323) c n a l d g s b h j k 3 12 notes: 1. dimensioning and tolerancing per ansi y14.5m, 1982. 2. controlling dimension: inch. dim min max min max millimeters inches a 0.071 0.087 1.80 2.20 b 0.045 0.053 1.15 1.35 c 0.032 0.040 0.80 1.00 d 0.012 0.016 0.30 0.40 g 0.047 0.055 1.20 1.40 h 0.000 0.004 0.00 0.10 j 0.004 0.010 0.10 0.25 k 0.017 ref 0.425 ref l 0.026 bsc 0.650 bsc n 0.028 ref 0.700 ref s 0.079 0.095 2.00 2.40 0.05 (0.002) style 4: pin 1. cathode 2. cathode 3. anode
baw56wt1 http://onsemi.com 6 notes
baw56wt1 http://onsemi.com 7 notes
baw56wt1 http://onsemi.com 8 on semiconductor and are trademarks of semiconductor components industries, llc (scillc). scillc reserves the right to make changes without further notice to any products herein. scillc makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does scillc assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages. atypicalo parameters which may be provided in scill c data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. all operating parameters, including atypicalso must be validated for each customer application by customer's technical experts. scillc does not convey any license under its patent rights nor the rights of others. scillc products are not designed, intended, or authorized 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 application in which the failure of the scillc product could create a sit uation 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 personal injury or death associated with such unintended or unauthori zed use, even if such claim alleges that scillc was negligent regarding the design or manufacture of the part. scillc is an equal opportunity/affirmative action employer. publication ordering information central/south america: spanish phone : 3033087143 (monfri 8:00am to 5:00pm mst) email : onlitspanish@hibbertco.com tollfree from mexico: dial 018002882872 for access then dial 8662979322 asia/pacific : ldc for on semiconductor asia support phone : 13036752121 (tuefri 9:00am to 1:00pm, hong kong time) toll free from hong kong & singapore: 00180044223781 email : onlitasia@hibbertco.com japan : on semiconductor, japan customer focus center 4321 nishigotanda, shinagawaku, tokyo, japan 1410031 phone : 81357402700 email : r14525@onsemi.com on semiconductor website : http://onsemi.com for additional information, please contact your local sales representative. baw56wt1/d thermal clad is a trademark of the bergquist company north america literature fulfillment : literature distribution center for on semiconductor p.o. box 5163, denver, colorado 80217 usa phone : 3036752175 or 8003443860 toll free usa/canada fax : 3036752176 or 8003443867 toll free usa/canada email : onlit@hibbertco.com fax response line: 3036752167 or 8003443810 toll free usa/canada n. american technical support : 8002829855 toll free usa/canada europe: ldc for on semiconductor european support german phone : (+1) 3033087140 (monfri 2:30pm to 7:00pm cet) email : onlitgerman@hibbertco.com french phone : (+1) 3033087141 (monfri 2:00pm to 7:00pm cet) email : onlitfrench@hibbertco.com english phone : (+1) 3033087142 (monfri 12:00pm to 5:00pm gmt) email : onlit@hibbertco.com european tollfree access*: 0080044223781 *available from germany, france, italy, uk, ireland
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