Overcurrent protection in electric vehicle systems using differential hall sensors

Abstract

In a particular embodiment, a current-sensing apparatus (1000) is disclosed that includes a conductive busbar (1003) defining a width and thickness and including a slot (1009). The apparatus also includes a core-less differential Hall sensor integrated circuit, IC (1007), mounted to a printed circuit board, PCB, the IC including first and second Hall plates. In this embodiment, the IC is positioned relative to the slot such that the first and second Hall plates sense opposing magnetic fields across an air gap defined by a stack-up of the PCB and a package portion of the IC.

Description

OVERCURRENT PROTECTION IN ELECTRIC VEHICLE SYSTEMS USING DIFFERENTIAL HALL SENSORSBACKGROUND

[0001] Electromechanical switching devices, including contactors and relays, connect and disconnect high-current circuits and are integral to electric vehicle power distribution. Electric vehicles ty pically employ multiple contactors to open and close current paths between battery packs and vehicle loads. During a battery short, the prospective short-circuit current can rise to tens of kiloamperes (e.g.. greater than 20 kA), exceeding component ratings; absent timely interruption, such currents can overstress conductors, contactors, and fuses, leading to rupture or catastrophic failure.SUMMARY

[0002] The following summary is meant to help one skilled in the art understand the various presently disclosed combinations of features. It is not meant to unduly limit the scope of any pending or future claims relating to the disclosure.

[0003] Conventional sensing paths, such as shunt-based arrangements requiring galvanic- isolation electronics, can introduce latency or uncertainty that delays interruption. The present disclosure addresses these issues by providing a geometry-defined, differential Hall sensing arrangement that delivers rapid, native-isolation detection with improved immunity to stray fields and tolerances, enabling earlier actuation of interruption devices to limit energy let-through and protect high-voltage components.

[0004] In various embodiments, cunent-sensing apparatuses, electric vehicle systems, and methods are disclosed in which a conductive busbar includes a slot and a core-less differential Hall sensor integrated circuit (IC) mounted on a printed circuit board (PCB). The IC includes first and second Hall plates positioned relative to the slot so that the plates sense opposing magnetic fields across an air gap defined by a stack-up of the PCB and a package portion of the IC. The apparatus and system use the resulting differential signal to monitor current in the busbar, with geometry7and placement selected to provide reliable magnetic coupling. In some embodiments, a magnetic transfer factor associated with the positioning and slot is determined to support calibration or verification. The method further includes evaluating the IC output against a trip criterion comprising a current threshold and / or a rate- of-change-of-current threshold and, when satisfied, actuating a pyrotechnic fuse. These arrangements provide native electrical isolation and enable rapid, robust overcurrent detection suitable for protecting high-voltage distribution components.

[0005] In a particular embodiment, a current-sensing apparatus is disclosed that includes a conductive busbar defining a width and thickness and including a slot. The apparatus also includes a core-less differential Hall sensor integrated circuit (IC) mounted to a printed circuit board (PCB), the IC including first and second Hall plates. In this embodiment, the IC is positioned relative to the slot such that the first and second Hall plates sense opposing magnetic fields across an air gap defined by a stack-up of the PCB and a package portion of the IC.

[0006] In another embodiment, an electric vehicle system is disclosed that includes a high voltage battery7and an electrical distribution system coupled to the battery. In this embodiment, the electrical distribution system includes a conductive busbar including a slot and a core-less differential Hall sensor integrated circuit (IC) mounted on a printed circuit board (PCB). The IC includes first and second Hall plates positioned relative to the slot such that the first and second Hall plates sense opposing magnetic fields across an air gap defined by a stack-up of the PCB and a package portion of the IC.

[0007] In another embodiment, a method of overcurrent detection and protection in an electrical power distribution system is disclosed that includes positioning a core-less differential Hall sensor integrated circuit (IC) relative to a slot of a conductive busbar such that first and second Hall plates of the IC sense opposing magnetic fields across an air gap defined by a stack-up of a printed circuit board (PCB) and a package portion of the IC. The method also includes monitoring an output of the IC. The method also includes actuating a pyrotechnic fuse when the output satisfies atrip criterion comprising at least one of a current threshold and a rate-of-change-of-current threshold indicative of a high prospective current event.

[0008] The foregoing and other objects, features and advantages of the invention will be apparent from the follow ing more particular descriptions of exemplary embodiments of the invention as illustrated in the accompanying drawings wherein like reference numbers generally represent like parts of exemplary embodiments of the invention.BRIEF DESCRIPTION OF THE DRAWINGS

[0009] One or more aspects of the present disclosure are discussed below with reference to the accompanying Figures. It will be appreciated that for simplicity and clarity of illustration, elements shown in the drawings have not necessarily been drawn accurately or to scale. For example, the dimensions of some of the elements may be exaggerated relative to other elements for clarity or several physical components may be included in one functional block or element. Further, where considered appropriate, reference numerals may be repeatedamong the drawings to indicate corresponding or analogous elements. For purposes of clarity, however, not every component may be labeled in every drawing. The Figures are provided for the purposes of illustration and explanation and are not intended to be limiting. In the Figures:

[0010] FIG. 1 sets forth an example electric vehicle pow er distribution sy stem for overcurrent protection using differential Hall sensors in accordance with at least one embodiment of the present disclosure.

[0011] FIG. 2 sets forth an example differential Hall sensor integrated circuit for overcurrent protection in electric vehicle systems using differential Hall sensors in accordance with at least one embodiment of the present disclosure.

[0012] FIG. 3 sets forth a flow chart for an example method of using a differential Hall effect sensor for overcurrent protection in electric vehicle systems using differential Hall sensors in accordance with at least one embodiment of the present disclosure.

[0013] FIG. 4A sets forth an example shunt-based current sensing arrangement.

[0014] FIG. 4B sets forth another example shunt-based current sensing arrangement.

[0015] FIG. 5 sets forth a chart of a finite element analysis in accordance with at least one embodiment of the present disclosure.

[0016] FIG. 6 sets forth a chart of another finite element analysis in accordance with at least one embodiment of the present disclosure.

[0017] FIG. 7 sets forth a chart of another finite element analysis in accordance with at least one embodiment of the present disclosure.

[0018] FIG. 8 sets forth a chart of another finite element analysis in accordance with at least one embodiment of the present disclosure.

[0019] FIG. 9 sets forth a table of proposed notch design and gain setting with resulting IC errors, position errors, stray field and backplate errors in accordance with at least one embodiment of the present disclosure.

[0020] FIG. 10A sets forth an exploded view of an example overcurrent protection assembly for overcurrent protection in electric vehicle systems using differential Hall sensors in accordance with at least one embodiment of the present disclosure.

[0021] FIG. 10B sets forth an assembled view of the example overcurrent protection assembly of FIG. 10A.

[0022] FIG. 11 sets forth a graph of voltage and current vs. time for a current break event in accordance with at least one embodiment of the present disclosure.

[0023] FIG. 12 sets forth a flowchart of a method of overcurrent detection and protection in an electrical power distribution system in accordance with at least one embodiment of the present disclosure.DETAILED DESCRIPTION

[0024] The terminology7used herein for the purpose of describing particular examples is not intended to be limiting for further examples. Whenever a singular form such as ’’a". “an” and “the” is used and using only a single element is neither explicitly or implicitly defined as being mandatory, further examples may also use plural elements to implement the same functionality. Likewise, when a functionality is subsequently described as being implemented using multiple elements, further examples may implement the same functionality using a single element or processing entity. It will be further understood that the terms “comprises”, “comprising”, ’‘includes” and / or “including”, when used, specify the presence of the stated features, integers, steps, operations, processes, acts, elements and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, processes, acts, elements, components and / or any group thereof.

[0025] It will be understood that when an element is referred to as being “connected” or “coupled” to another element, the elements may be directly connected or coupled via one or more intervening elements. If two elements A and B are combined using an “or”, this is to be understood to disclose all possible combinations, i.e. only A, only B, as well as A and B. An alternative wording for the same combinations is “at least one of A and B”. The same applies for combinations of more than two elements.

[0026] Accordingly, while further examples are capable of various modifications and alternative forms, some particular examples thereof are show n in the figures and will subsequently be described in detail. However, this detailed description does not limit further examples to the particular forms described. Further examples may cover all modifications, equivalents, and alternatives falling within the scope of the disclosure. Like numbers refer to like or similar elements throughout the description of the figures, which may be implemented identically or in modified form when compared to one another while providing for the same or a similar functionality.

[0027] Electromechanical contactors connect and disconnect circuits by selectively opening and closing conductive paths. A contactor is typically coupled in series with one or more sources or loads and operates between an open state that interrupts current flow- and a closed state that completes the circuit to control delivery of electrical power.

[0028] High-voltage electric vehicle power distribution systems employ contactors to connect battery packs, chargers, and traction inverters. Faults such as short circuits can produce rapidly rising prospective currents that may damage equipment if not interrupted promptly. Overcurrent protection schemes therefore monitor current and command an opening action or an auxiliary interruption device to limit energy' let-through and mitigate safety7risks. Existing approaches involve trade-offs among detection speed, galvanic isolation, accuracy, and susceptibility to stray magnetic fields.

[0029] In a battery short, system inductance causes current to rise with a finite slope rather than instantaneously. By detecting the event early — before the current reaches destructive levels — and signaling a controller to actuate a pyrotechnic fuse, the system can interrupt the fault sooner and reduce stress on contactors and other components.

[0030] Shunt-based current sensing can provide high accuracy but typically requires additional galvanic-isolation circuitry and may introduce latency in the detection path. Coreless differential Hall sensing provides native isolation and can offer faster detection, making it suitable where response time and cost are prioritized over absolute accuracy.

[0031] In certain embodiments, a slot formed in a busbar is selected to concentrate magnetic flux and improve magnetic coupling to a differential Hall sensor IC. Slot geometry, sensor placement, and the effective air gap influence transfer factor and error contributions, and may be evaluated using two-dimensional finite-element analysis. The design can also account for conductor resistance, cross-talk from adjacent conductors, effects of nearby ferritic structures, and positional tolerances.

[0032] For further explanation, FIG. 1 illustrates an example electric vehicle power distribution system 100. One or more loads 104 are coupleable to one or more battery7banks 102. A positive terminal of a battery cell array 110 is coupleable to a positive terminal of a point of load 120, and a negative terminal of the battery cell array 1 10 is coupleable to the point of load 120 through a series of switches. The point of load 120 can be, for example, a traction inverter.

[0033] Within the battery bank 102, a positive line is switched by switch 106 and a negative line is switched by switch 108, with a fuse 112 on the positive line. The battery bank 102 further includes at least one Hall sensor 114. Within the load 104, a positive line is switched by syvitch 116 and a negative line is syvitched by syvitch 118, with a fuse 122 on the positive line, and at least one Hall sensor 124. A charger 132 serves as a voltage source and is coupleable to the positive line via switch 130 and to the negative line via switch 128 to charge the battery cell array 110. A current sensor 126 measures charge and discharge currentat the battery bank 102, and the Hall sensors 114 and 124 provide branch diagnostics.

[0034] In high-voltage electric vehicle power distribution, fault currents can rise rapidly; early detection and interruption are required to limit energy let-through and protect contactors, conductors, and the battery pack. The disclosed arrangement employs a slotted busbar with a core-less differential Hall IC positioned so two Hall plates sense opposing fields across an air gap defined by the PCB and IC package. This geometry establishes predictable magnetic coupling for rapid detection using a native-isolation sensor path. Differential sensing suppresses common-mode magnetic fields and installation variability, supporting reliable trip decisions based on current and / or dl / dt. Relative to shunt approaches, the architecture may reduce power dissipation and eliminate separate isolation components; relative to single-ended Hall arrangements, it may improve immunity to stray fields. The slot and placement are tunable to different current ranges without changing the IC, facilitating platform reuse. These attributes enable earlier pyrotechnic fuse actuation and improved protection of battery disconnect units and associated equipment.

[0035] For further explanation, FIG. 2 illustrates the sensing principle of a core-less differential Hall sensor integrated circuit 200 used with a slotted busbar. The IC includes a first Hall plate BH1 204 and a second Hall plate BH2 202 positioned on opposite sides of an air gap g so that magnetic flux generated by current in the busbar passes through the plates in opposite directions. The plates produce signals proportional to their respective magnetic fields, and the IC forms a differential output corresponding to B diff = B H2 - B HI. Because external or parasitic fields tend to couple similarly into both plates, they appear as common-mode components that are substantially cancelled in the differential output.

[0036] In the disclosed apparatus, the air gap g is defined by the stack-up of the printed circuit board and a package portion of the IC, and the busbar slot concentrates flux at the plates. The combination of slot geometry, plate placement, and air-gap definition establishes a magnetic coupling — sometimes expressed as a transfer factor between busbar current and B_diff — that can be selected to support reliable overcurrent detection. This arrangement matters because it provides a fast, native-isolation sensing path with inherent rejection of stray fields and installation variation, enabling robust trip decisions (e.g.. current or dl / dt based) and early actuation of an interruption device such as a pyrotechnic fuse in electric vehicle battery disconnect units and related systems.

[0037] For further explanation, FIG. 3 presents a flow chart 300 of the sensing and design method for a core-less differential Hall arrangement used with a slotted busbar. The method models the magnetic transfer factor (TF) (also referred to as coupling factor (CF)) defined asthe differential magnetic field at the Hall plates per unit busbar current. TF is set primarily by the slot geometry and the air gap defined by the PCB and IC package stack-up. A higher TF reduces current-referred offset (field offset divided by TF) and preserves margin against gain error at an overcurrent decision point. TF may be determined using supplier references and / or two-dimensional finite-element analysis (FEA), such as finite element method magnetics (FEMM) driven from a scripting environment, and then used to select IC gain and trip criteria.

[0038] FIG. 4A depicts a representative shunt-based current sensing arrangement 402. FIG. 4B shows an alternative shunt arrangement 404. The disclosed apparatus replaces or complements these shunt approaches for overcurrent detection by positioning a core-less differential Hall IC adjacent to a slot in a busbar so that two Hall plates sense opposing fields across an air gap defined by the PCB and IC package. This geometry provides native galvanic isolation and a fast differential signal with inherent rejection of common-mode magnetic fields. In some implementations, the Hall-based path supplies the rapid trip signal for pyrotechnic fuse actuation, while a shunt (FIG. 4A / 4B) may be retained for high-accuracy metering; in other implementations, the Hall-based path serves as the primary overcurrent detector without a shunt.

[0039] For further explanation, FIG. 5 presents a chart 500 of two-dimensional finite-element results (e.g., FEMM) for the disclosed slotted-busbar arrangement. The plot shows the differential magnetic field at the Hall plates for a reference current as a function of notch geometry and thus illustrates the transfer factor (TF = B_diff / 1). This analysis links mechanical dimensions to sensing performance and guides the final geometry and IC gain used for overcurrent detection.

[0040] For further explanation, FIG. 6 presents a chart 600 of two-dimensional finite-element results evaluating magnetic cross-talk from a conductor routed parallel to the slotted busbar. The plotted quantity is cross-talk error due to a conductor parallel to the notch carrying the same current for geometries selected for the analysis in FIG. 5. Error generally decreases with increasing busbar separation. This analysis informs minimum routing clearances, preferred sensor placement on the slot centerline, and transfer-factor margin in the overcurrent trip budget so that cross-talk does not mask or delay detection.

[0041] For further explanation, FIG. 7 presents a chart 700 of two-dimensional finite-element results evaluating influence from a nearby ferritic back-plate (e g., chassis). It simulates a battery disconnect unit (BDU) mounted on a vehicle chassis. A BDU is a high-voltage subassembly in an electric vehicle that houses the main contactors, fuses, current sensors, andcontrol electronics used to connect or isolate the traction batten- from the rest of the power distribution system. It serves as the central protection and switching unit for charging and discharging the battery, and in fault conditions (such as a short circuit) it coordinates fast interruption — often by actuating contactors or a pyrotechnic fuse — to protect the battery and downstream components. The plot shows current-referred error at the differential output versus separation distance to the ferritic surface for representative slot and air-gap geometries. These results inform minimum clearances and transfer-factor margin so that proximity to vehicle structure does not compromise overcurrent detection.

[0042] For further explanation, FIG. 8 presents a chart 800 of two-dimensional finite-element tolerance analysis for the disclosed slotted-busbar arrangement. The analysis quantifies the change in differential field — and corresponding transfer factor — resulting from lateral displacement of the sensor relative to the slot centerline (X / Y), air-gap variation (Z), and angular misorientation of the IC package. Curves show relative sensitivity change versus displacement. These results establish permissible positioning tolerances, inform mechanical registration features that set the air gap and align the plates, and provide margin for calibration and trip-threshold selection.

[0043] For further explanation, FIG. 9 presents a table 900 that summarizes candidate slot (notch) geometries and associated IC gain settings together with the resulting performance metrics for the disclosed arrangement. For each candidate, the table lists the transfer factor and aggregates IC-related errors (e.g., offset and gain), positioning / tolerance errors (e.g.. sensor placement relative to the slot), and susceptibility to stray-field cross-talk and ferritic back-plate influence. The table thus links mechanical geometry and IC configuration to current-referred error at the differential output and identifies combinations that satisfy the overcurrent trip margin.

[0044] For further explanation, FIGs. 10A and 10B illustrate an assembly 1000 that positions a core-less differential Hall sensor IC 1007 relative to a busbar 1003. The busbar includes a notch 1001 forming a slot 1009 that concentrates magnetic flux at the sensor location. In FIG. 10A (exploded), a printed circuit board carrying the IC 1007 is located opposite the slot, and a mating connector 1050, housing 1052. nut 1054, compression limiter 1056. and bolt 1058 provide mechanical registration and fastening to locate the board with respect to the busbar and to establish the sensing air gap defined by the PCB and IC package stack-up. In FIG. 10B (assembled), the IC 1007 is adjacent to, or at least partially within, the slot 1009 so that its Hall plates straddle the slot across the air gap. with the IC package plane generally perpendicular to a broad face of the busbar. This arrangement yields repeatable magneticcoupling and maintains alignment tolerances suitable for reliable overcurrent detection.

[0045] For further explanation, FIG. 11 presents waveforms 1100 of voltage and current versus time during a short-circuit and interruption sequence. At 1102, a short-circuit is initiated and line current rises with a finite slope set by system inductance. At 1104, the differential Hall path detects an overcurrent condition (e.g., current and / or dl / dt threshold) and issues a trip signal. At 1106. an interruption device such as a pyrotechnic fuse begins to open, and at 1108 the current is extinguished and bus voltage recovers. In representative implementations, the Hall-based overcurrent detection path provides a substantially shorter response time than a shunt-based path using precision amplification and isolation, enabling earlier actuation and reduced energy let-through. By initiating the break before the fault current reaches its prospective peak, the arrangement improves protection of contactors and associated high-voltage components in the battery disconnect unit.

[0046] For further explanation, FIG. 12 is a flowchart of a method of overcurrent detection and protection in an electrical power distribution system. The method includes positioning 1202 a core-less differential Hall sensor integrated circuit (IC) relative to a slot of a conductive busbar such that first and second Hall plates of the IC sense opposing magnetic fields across an air gap defined by a stack-up of a printed circuit board (PCB) and a package portion of the IC. Positioning 1202 may be carried out by providing mechanical registration features on the busbar, PCB, and housing — such as datums, bosses, slots, and compression limiters — that locate the IC relative to the slot and set the air gap defined by the PCB and package stack-up.

[0047] In addition, the method of FIG. 12 also includes monitoring 1206 an output of the IC. Monitoring 1206 an output of the IC may be carried out by sampling a differential output with an analog-to-digital converter at a rate sufficient to capture expected current slew, with front-end anti-alias filtering and application of stored offset and gain corrections. Event detection may be carried out by evaluating the sampled signal against programmable criteria including magnitude thresholds, rate-of-change (dl / dt) limits, persistence window s, and hysteresis or digital filtering to suppress spurious trips from noise or stray fields. Supervision may be carried out by checking IC supply, temperature, and self-test indicators, validating signal plausibility against a second sensing channel (for example, an opposite-polarity busbar sensor), and communicating status to a controller that commands actuation of an interruption device.

[0048] The method of FIG. 12 also includes actuating 1208 a pyrotechnic fuse when the output satisfies a trip criterion comprising at least one of a current threshold and a rate-of-change-of-current threshold indicative of a high prospective current event. Actuating 1208 a pyrotechnic fuse may be carried out by issuing a command to a dedicated squib driver when the monitored output satisfies a trip criterion comprising at least one of a cunent-magnitude threshold and a rate-of-change-of-current threshold, optionally with persistence, hysteresis, and corroboration by a second sensing channel.

[0049] The disclosed method improves over shunt-based sensing and single-ended Hall arrangements by establishing a geometry -defined magnetic coupling — via a slotted busbar and an air gap set by PCB and IC package stack-up — that yields a predictable transfer factor for reliable, rapid overcurrent detection. Differential Hall sensing suppresses common-mode magnetic fields and installation variability, reducing false trips and allowing earlier, more decisive pyrotechnic-fuse actuation to limit energy let-through and protect contactors and high-voltage components. Native galvanic isolation eliminates separate isolation amplifiers and avoids shunt I2R losses, while slot geometry' and IC gain can be selected to meet different current ranges without changing the sensor architecture, enabling scalable, lower-complexity' designs.

[0050] In view of the foregoing, it will be appreciated that a differential Hall sensor in accordance with the present disclosure provides faster response than shunt-based solutions and is less expensive. Further, the differential Hall sensor in accordance with the present disclosure is more robust than other Hall based solutions. Still further, one sensor design can serve multiple current ranges by tuning the busbar design only.

[0051] Advantages and features of the present disclosure can be further described by the following statements:

[0052] 1. A current-sensing apparatus comprising: a conductive busbar defining a width and thickness and including a slot; and a core-less differential Hall sensor integrated circuit (IC) mounted to a printed circuit board (PCB), the IC including first and second Hall plates; wherein the IC is positioned relative to the slot such that the first and second Hall plates sense opposing magnetic fields across an air gap defined by a stack-up of the PCB and a package portion of the IC.

[0053] 2. The apparatus of statement 1, wherein the slot, the air gap, and IC position establish a magnetic transfer factor that satisfies a predetermined minimum selected to maintain at least one of sensor offset and sensor gain error w ithin a specified limit during overcurrent detection.

[0054] 3. The apparatus of any of statements 1-2, wherein the first and second Hall plates are arranged to provide a differential output that suppresses common-mode magnetic fields.

[0055] 4. The apparatus of any of statements 1-3, wherein the IC is at least partially disposed within the slot.

[0056] 5. The apparatus of any of statements 1-4, wherein a plane of a package of the IC is generally perpendicular to a broad face of the busbar.

[0057] 6. The apparatus of any of statements 1-5, wherein the busbar includes one or more notches.

[0058] 7. The apparatus of any of statements 1-6, wherein the differential Hall sensor integrated circuit is mounted proximate to the one or more notches.

[0059] 8. The apparatus of any of statements 1-7, wherein a number and geometry of the one or more notches is selected based on target measurement characteristics.

[0060] 9. The apparatus of any of statements 1-8, wherein the differential Hall sensor integrated circuit is communicatively coupled to an overcurrent protection system that includes at least one of a high voltage contactor and a pyrotechnic fuse.

[0061] 10. An electric vehicle sy stem comprising: a high voltage battery; and an electrical distribution system coupled to the battery, the electrical distribution system comprising: a conductive busbar including a slot; and a core-less differential Hall sensor integrated circuit (IC) mounted on a printed circuit board (PCB), the IC including first and second Hall plates positioned relative to the slot such that the first and second Hall plates sense opposing magnetic fields across an air gap defined by a stack-up of the PCB and a package portion of the IC.

[0062] 1 1 . The electric vehicle system of statement 10, wherein the slot, the air gap, and the IC position establish a magnetic transfer factor that satisfies a predetermined minimum selected to maintain at least one of sensor offset and sensor gain error within a specified limit during overcurrent detection.

[0063] 12. The electric vehicle system of any of statements 10-11, wherein the first and second Hall plates are arranged to provide a differential output that suppresses commonmode magnetic fields.

[0064] 13. The electric vehicle system of any of statements 10-12, wherein the IC is at least partially disposed within the slot.

[0065] 14. The electric vehicle system of any of statements 10-13, wherein a plane of a package of the IC is generally perpendicular to a broad face of the busbar.

[0066] 15. The electric vehicle system of any of statements 10-14, wherein the busbar includes one or more notches.

[0067] 16. The electric vehicle system of any of statements 10-15, wherein the differential Hall sensor integrated circuit is mounted proximate to the one or more notches.

[0068] 17. The electric vehicle system of any of statements 10-16, wherein a number and geometry of the one or more notches is selected based on target measurement characteristics.

[0069] 18. A method of overcurrent detection and protection in an electrical power distribution system, the method comprising: positioning a core-less differential Hall sensor integrated circuit (IC) relative to a slot of a conductive busbar such that first and second Hall plates of the IC sense opposing magnetic fields across an air gap defined by a stack-up of a printed circuit board (PCB) and a package portion of the IC; monitoring an output of the IC; and actuating a pyrotechnic fuse when the output satisfies a trip criterion comprising at least one of a current threshold and a rate-of-change-of-current threshold indicative of a high prospective current event.

[0070] 19. The method of statement 18, further comprising selecting the slot, the air gap, and IC position to establish a magnetic transfer factor that satisfies a predetermined minimum selected to maintain at least one of sensor offset and sensor gain error within a specified limit during overcurrent detection.

[0071] 20. The method of statement 18 or 19, wherein monitoring the output comprises forming a differential signal from the first and second Hall plates to suppress common-mode magnetic fields.

[0072] It will be understood from the foregoing description that modifications and changes may be made in various embodiments of the present disclosure without departing from its true spirit. The descriptions in this specification are for purposes of illustration only and are not to be construed in a limiting sense. The scope of the present disclosure is limited only by the language of the following claims.

Claims

CLAIMSWhat is claimed is:

1. A current-sensing apparatus comprising: a conductive busbar defining a width and thickness and including a slot; and a core-less differential Hall sensor integrated circuit (IC) mounted to a printed circuit board (PCB). the IC including first and second Hall plates; wherein the IC is positioned relative to the slot such that the first and second Hall plates sense opposing magnetic fields across an air gap defined by a stack-up of the PCB and a package portion of the IC.

2. The apparatus of claim 1, wherein the slot, the air gap, and IC position establish a magnetic transfer factor that satisfies a predetermined minimum selected to maintain at least one of sensor offset and sensor gain error within a specified limit during overcurrent detection.

3. The apparatus of claim 1, wherein the first and second Hall plates are arranged to provide a differential output that suppresses common-mode magnetic fields.

4. The apparatus of claim 1, wherein the IC is at least partially disposed within the slot.

5. The apparatus of claim 1 , wherein a plane of a package of the IC is generally perpendicular to a broad face of the busbar.

6. The apparatus of claim 1, wherein the busbar includes one or more notches.

7. The apparatus of claim 6, wherein the differential Hall sensor integrated circuit is mounted proximate to the one or more notches.

8. The apparatus of claim 6, wherein a number and geometry of the one or more notches is selected based on target measurement characteristics.

9. The apparatus of claim 1, wherein the differential Hall sensor integrated circuit is communicatively coupled to an overcurrent protection system that includes at least one of a high voltage contactor and a pyrotechnic fuse.

10. An electric vehicle system comprising: a high voltage battery’ ; and an electrical distribution system coupled to the battery, the electrical distribution system comprising: a conductive busbar including a slot; and a core-less differential Hall sensor integrated circuit (IC) mounted on a printed circuit board (PCB). the IC including first and second Hall plates positioned relative to the slot such that the first and second Hall plates sense opposing magnetic fields across anair gap defined by a stack-up of the PCB and a package portion of the IC.

11. The electric vehicle system of claim 10, wherein the slot, the air gap, and the IC position establish a magnetic transfer factor that satisfies a predetermined minimum selected to maintain at least one of sensor offset and sensor gain error within a specified limit during overcurrent detection.

12. The electric vehicle system of claim 10, wherein the first and second Hall plates are arranged to provide a differential output that suppresses common-mode magnetic fields.

13. The electric vehicle system of claim 10, wherein the IC is at least partially disposed within the slot.

14. The electric vehicle system of claim 10, wherein a plane of a package of the IC is generally perpendicular to a broad face of the busbar.

15. The electric vehicle system of claim 10, wherein the busbar includes one or more notches.

16. The electric vehicle system of claim 15, wherein the differential Hall sensor integrated circuit is mounted proximate to the one or more notches.

17. The electric vehicle system of claim 15, wherein a number and geometry of the one or more notches is selected based on target measurement characteristics.

18. A method of overcurrent detection and protection in an electrical power distribution system, the method comprising: positioning a core-less differential Hall sensor integrated circuit (IC) relative to a slot of a conductive busbar such that first and second Hall plates of the IC sense opposing magnetic fields across an air gap defined by a stack-up of a printed circuit board (PCB) and a package portion of the IC; monitoring an output of the IC; and actuating a pyrotechnic fuse when the output satisfies a trip criterion comprising at least one of a current threshold and a rate-of-change-of-current threshold indicative of a high prospective current event.

19. The method of claim 18. further comprising selecting the slot, the air gap, and IC position to establish a magnetic transfer factor that satisfies a predetermined minimum selected to maintain at least one of sensor offset and sensor gain error within a specified limit during overcurrent detection.

0. The method of claim 18, wherein monitoring the output comprises forming a differential signal from the first and second Hall plates to suppress common-mode magnetic fields.

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