Hall Effect Sensor

The US1881 is an inte­grat­ed Hall effect latched sen­sor. That’s nice but what does it do? Hold­ing a mag­net near the sen­sor will cause the out­put pin to tog­gle. This makes for a robust pres­ence sen­sor. A reed sen­sor also works nice­ly, but can be lim­it­ed by the glass encap­su­la­tion and size. A hall effect sen­sor is much small­er, but can han­dle less cur­rent than a reed switch.The device includes an on-chip Hall volt­age gen­er­a­tor for mag­net­ic sens­ing, a com­para­tor that ampli­fies the Hall volt­age, and a Schmitt trig­ger to pro­vide switch­ing hys­tere­sis for noise rejec­tion, and open-col­lec­tor out­put. An inter­nal bandgap reg­u­la­tor is used to pro­vide tem­per­a­ture com­pen­sat­ed sup­ply volt­age for inter­nal cir­cuits and allows a wide oper­at­ing sup­ply range.If a mag­net­ic flux den­si­ty larg­er than thresh­old Bop, DO is turned on (low). The out­put state is held until a mag­net­ic flux den­si­ty rever­sal falls below Brp caus­ing DO to be turned off (high).Fea­tures:3.5V to 24V DC oper­a­tion volt­ageLow cur­rent con­sump­tionTem­per­a­ture com­pen­sa­tionWide oper­at­ing volt­age rangeOpen-Col­lec­tor pre-dri­ver50mA max­i­mum sink­ing out­put cur­rentReverse polar­i­ty pro­tec­tionLead Free Pack­age: TO-92Doc­u­ments:DatasheetBil­dr Tuto­r­i­al