差分霍尔效应传感器

1、hal320 差分霍尔效应传感器1. 介绍hal320 是cmos工艺生产的差分霍尔开关。传感器内部包括2个温度补偿的霍尔盘（间距2.25mm），具有有效偏置补偿、带施密特触发器的差分放大器和一个开漏输出的晶体管。hal320是一个差分传感器，它能响应磁场的空间差异，两个霍尔盘（s1,s2）上的霍尔电压被一个差分放大器放大，差分信号与内部施密特触发器的实际开关水平比较，然后，驱动晶体管的开关。传感器具有双极开关特性，需要正和负值来实现正确的操作b = bs1 bs2产生b主要有两个方法： 旋转一个多极的圆环在传感器的封装前（适用hal300） 背装应用：在传感器封装后安装一个磁体，在两个霍尔盘

2、上产生后偏置的磁场。差分信号b通过旋转的铁磁性目标调制后偏置的磁场。(适用hal320)有效的偏置补偿保证在整个供电范围内和温度内保持不变的磁特性。传感器为工业和汽车电子应用设计，工作4.5 v 到 24 v环境温度40 °c 到 150 °c。hal320主要应用于：轮速、点火正时、abs、在极端的汽车和工业环境下旋转计数。1.1.主要特征 两个霍尔盘间距：2.25 mm 工作电压4.5 v to 24 v 过压保护 vdd-pin反向电压保护 通过温度关断实现输出短路保护 工作磁场：直流 to 10 khz 输出变低随封装前南极磁场强度变化，s1的磁通大于s2的磁通 片

3、上温度补偿电路使得磁参数受温度和供电影响的偏移最小 由温升引起的磁通密度的减少可以内置负温度系数磁滞损失系数进行补偿 emc 符合 iso 7637标准1.2. 标记代码所有霍尔传感器在封装表面有一个标记，标记包含了传感器名和温度范围。1.3. 工作节点温度范围 (tj)the hall sensors from micronas are specified to the chip temperature (junction temperature tj).hal320只有a温度范围a: tj = 40 °c to +170 °c1.4. 霍尔传感器代码halxxxpa-t

4、温度范围: a封装： sf-sot89b-2 ua-to92ua 型号: 320举例：hal320ua-a型号：320封装：to92ua温度：tj = 40 to +1701.5. 可焊性所有分装焊接符合iec68-2-58标准手工和回流焊接的最高温度为2601.6. 管脚2 gnd3 输出2. 功能描述hal320是个单片集成电路，有两个间距为2.25mm的霍尔盘，它随一个差分磁场而开关。如果磁力线与敏感面正交，霍尔盘产生与磁场成比例的霍尔电压。霍尔电压与实际门限电压比较。温度依耐偏执增加霍尔的供电电压和调整。在高温时温度依赖偏置增加霍尔盘电压并调整开关点减少磁场的感应。如果不同的磁通超过域

5、值水平开路输出开关相应位置。迟滞电路消除摆动并提供没有摆动的稳定输出。foscbonvout vohvoliddmagnetic offset caused by mechanical stress at the hall plates is compensated for by using the “switching offset compensation technique”: an internal oscillator provides a two phase clock (see fig. 22). the difference of the hall voltages is sa

6、mpled at the end of the first phase. at the end of the second phase, both sampled differential hall voltages are averaged and compared with the actual switching point. subsequently, the open drain output switches to the appropriate state. the amount of time that elapses from crossing the magnetic sw

7、itch level to the actual switching of the output can vary between zero and 1/fosc.shunt protection devices clamp voltage peaks at the output-pin and vdd-pin together with external series resistors. vdd脚的反向电流是被限制的通过一个内部串接电阻，在0-15v之间vdd脚无需反向保护二极管fig. 21: hal320 block diagramfig. 22: timing diagram3. s

8、pecifications3.1. outline dimensionsfig. 31:sot89b-2: plastic small outline transistor package, 4 leads, with two sensitive areas weight approximately 0.039 gfig. 32:to92ua-4: plastic transistor standard ua package, 3 leads, not spread, with two sensitive areas weight approximately 0.105 g3.2. 敏感面尺寸

9、 0.08 mm x 0.17 mm3.3. 敏感面位置 (nominal values)sot89b-2to92ua-3/-4x1 = -1.125 mmx2 = 1.125 mmx1 - x2 = 2.25 mmy = 0.95 mmy = 1.0 mmbd = 0.2 mm3.4. absolute maximum ratingsstresses beyond those listed in the “absolute maximum ratings” may cause permanent damage to the device. this is a stress rating on

10、ly. functional operation of the device at these conditions is not implied. exposure to absolute maximum rating conditions for extended periods will affect device reliability.this device contains circuitry to protect the inputs and outputs against damage due to high static voltages or electric fields

11、; however, it is advised that normal precautions be taken to avoid application of any voltage higher than absolute maximum-rated voltages to this high-impedance circuit.all voltages listed are referenced to ground (gnd).symbolparameterpin no.min.max.unitvddsupply voltage115281 )vvooutput voltage30.3

12、281 )viocontinuous output on current330matjjunction temperature range40401501702)°c1) as long as tjmax is not exceeded2) t < 1000h3.4.1. storage and shelf lifethe permissible storage time (shelf life) of the sensors is unlimited, provided the sensors are stored at a maximum of 30 °c and

13、 a maximum of 85% relative humidity. at these conditions, no dry pack is required.solderability is guaranteed for one year from the date code on the package.3.5. 推荐工作条件functional operation of the device beyond those indicated in the “recommended operating conditions” of this specification is not imp

14、lied, may result in unpredictable behavior of the device and may reduce reliability and lifetime.所有电压参考为地（gnd）symbolparameterpin no.min.max.unitvdd 供电电压14.524vio连续输出电流320mavo输出电压324v3.6. 特性characteristics at tj = 40 °c to +170 °c , vdd = 4.5 v to 24 v, gnd = 0 vsymbolparameterpin no.min.ty

15、p.max.unitconditionsidd供电电流12.84.76.8matj = 25 °cidd工作电流在整个温度范围内11.84.77.5mavddzovervoltage protectionat supply128.532.5vidd = 25 ma, tj = 25 °c,t = 20 msvozovervoltage protection at output32832.5vio = 25 ma, tj = 25 °c,t = 20 msvoloutput voltage overtemperature range3180400mvio = 20

16、maiohoutput leakage current overtemperature range30.0610µavoh = 4.5 v.24 v,b < boff , tj 150 °cfoscinternal oscillatorchopper frequency62khzten(o)enable time of outputafter setting of vdd335µsvdd = 12 v,b > bon + 2mt orb < boff 2mttroutput rise time380400nsvdd = 12 v, rl = 82

17、0 ,cl = 20 pftfoutput fall time345400nsvdd = 12 v, rl = 820 ,cl = 20 pfrthjsbcasesot89b-2thermal resistance junction tosubstrate backside150200k/wfiberglass substrate30 mm x 10 mm x 1.5 mm(see fig. 36)rthjscaseto92ua-3,to92ua-4thermal resistancejunction to soldering point150200k/wat recommended oper

18、ation conditions if not otherwise specified in the column “conditions”. typical characteristics for tj = 25 °c and vdd = 12 v3.7. magnetic characteristics at tj = 40 to +170, vdd = 4.5 v to 24 v typical characteristics for vdd = 12 v开关动点的磁通密度值 (condition: 10 mt < b0 < 10 mt)正的磁通密度值指定为南极 b

19、 = bs1 bs2parametermin.40 typ.max.min.25 typ.max.min.170typ.max.unit开点 bonb > bon1.51.22.5-1.51.22.52.51.13.5mt关点 boffb < boff2.50.61.52.50.61.53.50.42.5mt迟滞hys = bon boff11.8411.840.81.54mt偏置boffset = (bon +boff)/220.3220.3230.43mt在背置应用，两个霍尔盘s1 s2的灵敏度的不匹配导致一个额外的磁开关点偏置。在背置应用磁通预感应值b0，这个灵敏度不匹配通常

20、的磁偏置boffsetbb = |s1 s2|/s1 b0 + bffset.parameter40 °c25 °c170 °cunitsensitivity mismatch1)|s1 s2|/s11.52)1.02)0.52)%1) 包装的机械应力能影响灵敏度的不匹配2) 所有值均为典型值磁开关的测试在磁通预感应为b0 = 150 mt的室温下进行.这些参数在外界压力和传感器的寿命期间会变化。 parametermin.25 °ctyp.max.unit开点 bonbb4.51.55.5mt关点 boffbb5.50.34.5mt迟滞 bhys11.

21、84mt偏置 boffsetbb50.6+5mtbhysb = bs1 bs2fig. 37: 开关点和迟滞定义mt 2.01.5bon boff1.0ta = 40 °c ta= 25 °c ta = 100 °c ta = 150 °c 1.0 1.520510 15 20 25 30 vvddfig. 38: magnetic switch points versus supply voltage0.50.00.5boffmt 2.01.0ta1.5bon boff0.50.00.5fig. 310: magnetic switch points

22、versus temperaturevdd = 12 v 1.0 1.5 2 50050100 150 200°cmt 2.01.5bon boff1.00.5ta = 40 °c0.0ta= 25 °c ta = 100 °c0.5ta = 170 °c 1.0boff33.5 4.0 4.5 5.0 5.5 6.0 vvddfig. 39: magnetic switch points versus supply voltagebon 1.52105ma 2540°cta=25 °cta =ta =150°c

23、10 15 15 10 5 0 5 10 15 20 25 30 vvddfig. 311: typical supply current versus supply voltageidd20150 5micronas9500io = 20 mavol 400300ta = 150 °c200ta = 25 °c ta = 40 °c1000 0510 15 20 25 30 vvddfig. 314: typical output low voltage versus supply voltagema 87idd654321050050100 150 200&#

24、176;ctafig. 313: supply current versus ambient temperaturevdd543210 123456 vfig. 312: supply current versus supply voltagema 87mv 5000 50tavol 400vdd =4.5 v050100 150 200°cfig. 315: typical output low voltage versus ambient temperature300200100io = 20 ma10micronasdata sheethal320khz 70403020100

25、0510 15 20 25 30 vvddfig. 316: typical internal chopper frequency versus supply voltageta = 25 °c60fosc500 50takhz 70050100 150 200 °cfig. 318: typical internal chopper frequency versus ambient temperaturevdd = 12 v504030201060fosckhz 70302010033.5 4.0 4.5 5.0 5.5 6.0 vvddfig. 317: typical

26、 internal chopper frequency versus supply voltage60fosc5040ta10 2fig. 319: typical output leakage current versus ambient temperatureµa 102103104050101ioh10010 110 5 50100 150 200 °cmicronas11ioh100voh101ta = 125 °c10 110 210 310410 5 2022ta = 75 °cta = 25 °c24262830 vfig. 32

27、0: typical output leakage current versus output voltageµa102 vdd = 5 v4.应用笔记机械应力能改变霍尔盘的灵敏度，磁场开关点也受到影响。如果传感器用在背置条件下应该避免外机械应力。传感器的压电灵敏度不能完全被偏置补偿技术克服。为了保证在背置应用的传感器的开关动作，最小的差分磁场调制应该大于磁场预感应值的10%。4.1 扩展工作条件工作电压可以低于4.5 v典型的传感器可工作在电压3v以上，然而低于4.5v有些参数会超出给定值.4.3. 启动特性为了保证有效的补偿特性，传感器有一个初始化时间。在初始化时间，输出状态时不确定的并且输出锁定的。初始化时间过后，如果磁场b大于bon输出为低，如果b小于boff输出为高。如果磁场在boff 和 bon之间，输出状态或是高或者是低，为了达到一个好的输出状态定义，磁场必须大于bonmax 或小于boffmin。4.4. emc and esd为了应用在电源干扰或辐射干扰，按图4推荐串联电阻和电容。串联电阻和电容离传感器尽可能近。这样应用通过产品标准iso7637的emc测试警告:不要将