明纬电源MHB75系列75W DC DC半砖稳压单组输出转换器.PDF

明纬电源MHB75系列75W DC-DC半砖稳压单组输出转换器PDF,伽75WDC-DC半砖稳压单组输出转换器MHB75系列■外部输出调整+vin+Vin+Vout(pin 1)(pin 1)(pin 9)RTrrim-downTrimMHB75 (pin7)TrimMHB75(pin7)RTrim-upRn-Vout-Vin(pin4)(pins算术1:修正电压上升接线算术2:修正电压下降接线The value of Rtrim-up defined asThe value of RTr m-down defined as(R1-R2X(Vo-Vo, nom))(R1-R2X(Vo, nom-Vol)RTrim-up(K2)RTrir-down(Kg2)(Vo-Vo, nomVo, nom-Vo)Where: RTrim-up is the external resistor in KohmWhere: RTrim-down is the external resistor in KohmVo, nom is the nominal output voltageVo, nom is the nominal output voltageVo is the desired output voltageVo is the desired outout voltageR1 and r2 are inside the unit and list in table 1R and r2 are inside the unit and ist in table 2OutputOutputVoltage(V)(Kohm)I(Kohm)Voltage(V)(Kohm)I(Kohm)5V588.255V5.810.5712V1965613.30412v864524V42.21516.92324V430Table 1Table 2For example, to Trim-up the outputFor example, to Trim-down the outputvoltage of 5.0V model (MHB75-48S05)Voltage of 5.0V model (MHB75-48S05by 8% to 5. 4V, RTrim-up is calculatedby 8% to 4.6V, RTrim-cown isas follows:alculated as followsVo- Vo. nom=54-5.0=0.4VVo.nom-Vo=5.0-4.6=0.4V1=5.8KohR1=5.8KR2=8.25 KohmR2 =10.57 Kohm58-8.25×0.458-10.57×04=6.25(Kg2)Trim-doiw3.93(K2)0404File Name: MHB75SPEC 2011-09-c8伽75WDC-DC半砖稳压单组输出转换器MHB75系列热曲线MHB75系列的工作温度范围为-40C~+100C.当MHB-75系列工作时,适当的降载或风冷是必需的在任何工作条件下,外壳最高温度不可超过100°C下图为MHB75系列没散热片时的降额出线Power Dissipated VS Amb ient Temperature and Air Flow without heatsink-Natural Convection4520t.min.(0.1ms)100 ft /min (0.5 m/s)200 ft. min. (1.0 m/s)米-300fmin.(1.5m/s)400 ft /min (2.0 m/s)分20+500 ft /min. (2.5 m/s)600fmin.(30m/s)700mnin.(3.5m/s)-800 ft /min.(4.0m/s)0203060708090100Ambient Temperature, Ta(C)Air Flow RateTypical Rca Air Flow Rate Typical RcaNatural convection20f/min (0. 1m/s)7.12C/W500mn.(2.5m2.96C/W Rca: Thermal resistance from case toambience100tmn(05ms)6.21C/W60/mn(30ms)2.53℃/W200fmn(10m)5.17℃/W700tmin.(3.5m/s)2.37℃/W300m(15ms)4.29c/W800min40ms)219c/W400fmn(20ms3.64c/WExampleWhat is the minimum airflow necessary for a MHB75-48S12 operates at nominal line, an output current of 6.25A, and a maximum ambienttemperature of40℃SolutionGiven: Vin=48Vdc, Vo=12Vdc, Io=6. 25A, n(unit efficiency) =89%Determine Power dissipation(Pd)Pd=Pi-Po=Po(1-n)nd=12×625×(1-0.89)/0.89=927WatsDetermine airflowGiven: Pd=9. 27W and Ta=40CCheck Thermal curve aboveminimum airflow= 100 ft /minVerifying: The maximum temperature rise△T= Pdx Rca=927×621=57.57℃The maximum case temperature Tc=Ta+△T=97.57℃<100℃Where The rca is thermal resistance from case to ambienceThe ta is ambient temperature and the tc is case temperatureFile Name: MHB75SPEC 2011-09-c8伽75WDC-DC半砖稳压单组输出转换器MHB75系列■机壳散热片(可选)单位mm型号:MC308(垂直方向散热片)型号:MC091(水平方向散热片)型号:MC092(水平方向散热片48.2050808R定R1030Rea3. 90C/W(typ ) at natural convection4.70C/W(typ ) at natural convection3.00C/W(typ ) at natural convection1. C/W(typ ) at 100ft. /min. LFM)1.33C/W(typ ) at 200ft. min ( LFM)2.89C/W(typ ) at 100ft. /min (LFM)1.44C! W(typ ) at 100ft. min (LFM2.30C/W(typ ) at 200ft. /min (LFM)1.17C/W(typ ) at 200ft. min (LFM)1.12C/W(typ ) at 300ft /min. LFM)1. C/W(typ ) at 300ft. min LFM)1.04C/W(typ ) at 300ft/min. LFM)0. 97C/W(typ ) at 400ft /min (LFM)1.59C/W( typ ) at 400ft /min ( LFM)0.95C/W(typ ) at 400f /min (LFM)File Name: MHB75SPEC 2011-09-c8伽75WDC-DC半砖稳压单组输出转换器MHB75系列■散热片组装螺丝垫圈散热片导热片或合适的散热油散热片编号MC308M-C092M-C092导热片:56.9X60X0.25mm螺丝:SMP+SWM3X8L■电磁兼容建议电路※要求如下图外加元件以符合EN55022 class a传导要求+Vinn+Vout+outCC2MHB75Lo adCase -Vout-VoutC3Model no2C3L1100uF/50V100uF/50VMHB75-12S ESR<0.33Q2 ESR<0.33921000pF1.5uH100uF/50v100uF/50VMHB7524SEsR0332ESR433210015033F/100V33F100VMHB7548二EsR<04652EsR<04692200pF8.3uH□=05,12,24File Name: MHB75SPEC 2011-09-c8