DE102009000460A1 - Current-controlled Hall sensor - Google Patents

Abstract

The invention relates to a current-controlled Hall sensor (3) having an electrical capacitor (23) which is electrically operatively connected to the supply voltage-independent detection of magnetic fields with electrical connections of the Hall sensor (3). H (1) provided with a housing (13) enclosing at least the Hall sensor (3), from which connection legs (6, 8) assigned to the terminals lead out, wherein the capacitor (23) for bridging the connections with the connection legs (6 , 8) is connected.

Description

The The invention relates to a current-controlled Hall sensor with a electrical capacitor, for the supply voltage independent detection of Magnetic fields with electrical connections of the Hall sensor electrically is actively connected.

State of the art

Hall sensors are known from the prior art. They are in these days many applications used to detect magnetic fields. Three main evaluation methods are known: the analogue Evaluation, the digital voltage-based and the digital current-guided evaluation. In particular, the last variant with a current-controlled Hall sensor is due to its high robustness against interference in the electrical Lines preferred. Voltage-based Hall sensors react against it sensitive to disturbances in the supply voltage.

Around supply voltage independently Using a Hall sensor to detect magnetic fields, the Hall sensor associated with an electrical capacitor connected to electrical terminals of the Hall sensor is electrically operatively connected, whereby the Hall sensor as magnetic field-controlled Power source can be used. The capacitor fulfills this Multiple functions: It serves as a support capacity, increases the ESD resistance and improves about that In addition, the EMC properties. For SMD components (surface-mountable Components) it is possible to use the Capacitor close to the Hall sensor to arrange, causing his Effectiveness increased. For "wired" types then has the likewise "wired" capacitor near of the Hall sensor are placed, but what with today's space reductions difficult.

Disclosure of the invention

Of the Hall sensor according to the invention is characterized by the design as a Hall sensor unit, with a housing enclosing at least the Hall sensor, from which the connections assigned Lead out connecting legs, wherein the capacitor for bridging the terminals with connected to the connecting legs. So it is envisaged that the Hall sensor and the capacitor as a Hall sensor unit, so as a coherent one and in particular be designed together composite. Wherein the Hall sensor is enclosed by a housing, and his connections Associated with connecting legs, which lead out of the housing. Outside the case can thereby the Hall sensor in a simple manner over the Connecting legs are contacted electrically. In addition, the Connecting legs also for mechanically fixing the Hall sensor unit, for example, on a printed circuit board used. For example can the connecting legs in corresponding receiving openings of a printed circuit board plugged in and soldered in it become. The capacitor is to bridge the connections, for supply voltage independent Detecting magnetic fields, connected to the connection legs. Of the electrical contact of the Hall sensor to the capacitor is thus on the Connecting legs created. By training as a Hall sensor unit The capacitor forms an integral part, so it always is arranged close to the Hall sensor. About the connecting legs, usually easier to contact than the terminals of the Hall sensor itself, can in a simple way the electrical connection ensured to the capacitor become.

advantageously, The connection legs have housing-internal and housing-external areas. This means that the connecting legs are partially in the housing and partially outside of the housing run. This allows the Connection legs to be particularly stable held on the housing, whereby the Hall sensor unit is particularly robust.

To a development of the invention, the connecting legs each at least one capacitor bearing surface for the capacitor. As the name already says, the capacitor is in the mounted state on the capacitor bearing surfaces of Connecting legs on. The condenser contact surfaces ensure a secure electrical contact and can about that also serve for mechanical securing of the capacitor. by virtue of In this type of mounting, the capacitor can be very close to the Hall sensor can be arranged, whereby an optimal effect is achieved.

Conveniently, are the capacitor pads formed as enlarged punched surfaces. The connecting legs are in the manufacture of the Hall sensor unit expediently as Punching grid made. It is in a simple way possible, To provide widespread areas on the connecting legs. So, for example the usual with punched lattices widened connecting areas, which are later severed used and optionally in addition enlarged provided so that the capacitor safely on the thus formed Capacitor-bearing surfaces lies.

Advantageously, the capacitor bearing surfaces are formed in the housing-external areas of the connecting legs. So the capacitor can easily after a Einhau tion of the advantageously formed as a semiconductor element Hall sensor with the latter are electrically connected. An exchange of the capacitor in case of need, for example, during maintenance, is possible. Conveniently, the capacitor is soldered to the capacitor bearing surfaces to ensure safe electrical contact and a secure fit during operation.

In a further embodiment the invention, the capacitor bearing surfaces in the housing-internal Formed areas of the connecting legs. This is also the capacitor even in the case, in which the Hall sensor and the housing-internal areas of the connecting legs arranged are. This will increase the stability the Hall sensor unit further increased, since now also the capacitor through the housing self-protected and kept. The housing is expediently a bit bigger than formed in the previously described embodiment. The Assembly of the Hall sensor unit is characterized overall easier, since the Hall sensor unit now even easier to handle.

Conveniently, are the capacitor pads the external housing Areas close to the housing designed so that the capacitor as close as possible to the Hall sensor is arranged, and the highest possible effectiveness of the "external" capacitor can be achieved.

Farther is provided that the capacitor as a ceramic capacitor, ie as an electrical capacitor with a ceramic dielectric is trained. Such ceramic capacitors are insensitive across from Voltages and overvoltage pulses and withstand high temperatures.

Further is provided that the connections of the Hall sensors using bond connections connected to the connection legs.

Finally is provided that the housing a mold housing is. This is in the manufacture of the Hall sensor unit the Hall sensor, in areas around the connecting legs and possibly injected or poured around the condenser. The mold housing is an electrically non-conductive Plastic housing. By the Umgießen / overmolding of the parts of the Hall sensor unit creates a particularly mechanically strong or stable Unit.

in the The invention is based on several embodiments be explained in more detail.

To demonstrate

1 a first embodiment of an advantageous Hall sensor in a schematic representation and

2 A second embodiment of an advantageous Hall sensor in a schematic representation.

The 1 shows a schematic representation of a first embodiment of a Hall sensor unit according to the invention 1 , The Hall sensor unit 1 has one as a semiconductor element 2 trained Hall sensor 3 on, on a support surface (English: the attach) or on a substrate 4 is arranged. The substrate 4 is part of a stamped grid 5 which still has three connecting legs 6 . 7 . 8th has, of which the connecting leg 7 is opti onal. The connecting legs 6 . 7 . 8th are aligned parallel to each other and have their Hall sensor 3 each opposite end of a contact surface 9 . 10 . 11 on. By means of bonds 12 is the Hall sensor 3 each with one of the contact surfaces 9 . 10 . 11 electrically connected. While the connecting legs 6 and 8th subsequently from the stamped grid 5 were disconnected, goes the optional connecting leg 7 in the substrate 4 on which the Hall sensor 3 is arranged over. The connecting legs 6 . 7 serve as connection lines for a supply voltage, or for one the signals of the Hall sensor 3 detecting evaluation unit, such as a microcontroller, while the connecting leg 8th serves as ground wire. The connecting legs 6 and 7 are often grouped together with current-controlled (Hall) sensors. For compatibility and strength reasons, the connecting leg remains 7 often received.

The Hall sensor 3 , the substrate 4 , the bonds 12 as well as the connecting legs 6 . 7 . 8th in the area of their contact surfaces 9 . 10 . 11 are from a housing 13 as a (transfer) mold housing 14 is formed, enclosed. In the present case thus form the contact surfaces 9 . 10 . 11 housing internal areas 15 . 16 . 17 the connecting legs 6 . 7 . 8th ,

The remaining area of the respective connecting leg 6 . 7 . 8th accordingly forms a housing-external area 18 . 19 . 20 that is outside the case 13 lies. In her housing-external area 18 . 19 . 20 are close to the housing 13 on the connecting legs 6 and 8th each a capacitor bearing surface 21 . 22 educated. On the capacitor bearing surfaces 21 . 22 is a capacitor 23 that as a ceramic capacitor 24 is formed, arranged and electrically connected thereto. The capacitor 23 thus bridges the legs 6 and 8th associated connections of the Hall sensor 3 , Advantageously, the condensate gate 23 with its contact ends on the corresponding capacitor pad 21 and 22 soldered to ensure safe electrical and mechanical contact.

Due to the advantageous close arrangement of the capacitor 23 to the Hall sensor 3 is this Hall sensor unit 1 or the Hall sensor 3 effectively usable as a current-conducted Hall sensor for the supply voltage independent detection of magnetic fields. The spatial proximity of the capacitor 23 to the Hall sensor 3 leads to a particularly effective EMC property and increased ESD resistance. In addition, the capacitor 23 usable as a backup capacity, whereby the reliability is increased in network fluctuations. The usual with clocked sensors "chopper peaks" can due to the spatial proximity of the capacitor 23 be optimally suppressed. The stamped grid construction and the connection of the capacitor 23 on the connecting legs 6 and 8th allows a particularly simple and inexpensive production of the Hall sensor unit 1 , which also withstands high temperatures or temperature differences.

The 2 shows a schematic representation of a second embodiment of the Hall sensor unit according to the invention 1 , wherein like parts are provided with the same reference numerals, so that reference is made to the preceding figure. In contrast to the previous embodiment, now the capacitor bearing surfaces 21 and 22 in the housing-internal areas of the connecting legs 6 . 8th trained and thus also the capacitor 23 in the case 13 arranged. The housing 13 is designed to be correspondingly larger or longer. The second embodiment has the advantage that the capacitor 23 now also through the housing 13 is supported and held and overall thereby a higher mechanical stability is ensured. In addition, the capacitor 23 inside the case 13 arranged so that, among other things, the installation and handling of the Hall sensor unit 1 simplified.

Due to the particularly compact design of the Hall sensor unit 1 , in which no further external components are needed, a space saving is achieved in comparison to known solutions. The current-controlled Hall sensor unit 1 For example, it is also possible to arrange components having little installation space, such as, for example, brush holders of an electrical machine, and thus to connect them both mechanically and electrically in a simple manner. Due to the advantageous embodiment, moreover, the life of the Hall sensor 3 or one the Hall sensor unit 1 extended device and ensures high reliability, since there are only a small number of solder / contact points, which could fail.

Claims (10)

Current-controlled Hall sensor ( 3 ) with an electric capacitor ( 23 ) for the supply voltage-independent detection of magnetic fields with electrical connections of the Hall sensor ( 3 ) is electrically operatively connected, characterized by the design as a Hall sensor unit ( 1 ) with at least the Hall sensor ( 3 ) enclosing housing ( 13 ), from which the terminals associated terminal legs ( 6 . 8th ), whereby the capacitor ( 23 ) for bridging the connections with the connection legs ( 6 . 8th ) connected is. Hall sensor according to claim 1, characterized in that the connecting legs ( 6 . 8th ) housing-internal areas ( 15 . 16 . 17 ) and housing-external areas ( 18 . 19 . 20 ) exhibit. Hall sensor according to one of the preceding claims, characterized in that the connecting legs ( 6 . 8th ) at least one capacitor bearing surface ( 21 . 22 ) for the capacitor ( 23 ) exhibit. Hall sensor according to one of the preceding claims, characterized in that the capacitor bearing surfaces ( 21 . 22 ) are formed as enlarged punched surfaces. Hall sensor according to one of the preceding claims, characterized in that the capacitor bearing surfaces ( 21 . 22 ) in the housing-external areas ( 18 . 20 ) are formed. Hall sensor according to one of the preceding claims, characterized in that the capacitor bearing surfaces ( 21 . 22 ) in the housing-internal areas ( 15 . 16 . 17 ) are formed. Hall sensor according to one of the preceding claims, characterized in that the capacitor bearing surfaces ( 21 . 22 ) of the housing-external areas ( 18 . 19 ) close to the housing ( 13 ) are formed. Hall sensor according to one of the preceding claims, characterized in that the capacitor ( 23 ) as a ceramic capacitor ( 24 ) is trained. Hall sensor according to one of the preceding claims, characterized in that the terminals of the Hall sensor ( 3 ) by means of bond connections ( 12 ) with the connection legs ( 6 . 7 . 8th ver are bound. Hall sensor according to one of the preceding claims, characterized in that the housing ( 13 ) a mold housing ( 14 ).