An Integrated On-Chip Flux Concentrator for Galvanic Current Sensing

Abstract

This is a repository copy of An Integrated on-chip flux concentrator for galvanic current sensing.

Development of GaN Transducer and On-Chip Concentrator for Galvanic Current Sensing

“…The conversion factor and inductance of the single loop structure (along LL in Figure 5 (a)) is plotted in Figure 7 (squares). The conversion factor reduces from 96 mT/A for a L W=15 15µm 2 active device area in [15] to 58 mT/A as the length increases and the magnetic field reduces due to the increase in separation of the current paths.…”

“…Figures 5 (a) and 5 (b) are top and side view of the single loop magnetic flux concentrator, respectively, proposed in [15] for 15µm 15µm active device area. The magnetic field in this zigzag shaped magnetic film penetrates the substrate at the points of discontinuity, marked B and C in Figure 5 (b), converting the horizontal field to the vertical one [15]. The magnetic field at the surface of sensor in the normal direction can be related to the current through loop by:…”

“…The transfer (ID-VGS) characteristics and sensitivity values are given at different biasing conditions and the effect of gate length on the sensitivity is investigated at room temperature. In addition, since the MagHEMTs fabricated possess long channels to enhance the Hall geometrical correction factor (GH), a single loop flux concentrator we had previosuly demonstrated [15] is modified and a novel spiral magnetic flux concentrator in closest approximity to the sensor to improve the conversion factor for long MagHEMTs is examined. In rectangular split-drain current sensors operating in the linear mode, the current difference between the two drains is called Hall current (IH) and is expressed by [16]: 1where µH is Hall mobility, is applied magnetic field in zdirection (perpendicular to device surface), L is device length, W is device width, ID is output current and GH is Hall geometrical correction factor, a ratio of Hall voltage in a real Hall plate to ideal (infinite) Hall plate [17].…”

Three-Phase Motor Inverter and Current Sensing GaN Power IC

“…GaN-based sense-FET ICs have been already demonstrated monolithically [ 31 , 32 , 33 , 34 , 35 , 36 , 37 ] and also by external wiring of several GaN devices [ 30 , 38 ] for single discrete transistors and used in half-bridges. This work focuses only on current-mirror sensing; other current sensing methods such as shunt-sensor [ 39 , 40 , 41 , 42 , 43 ] or hall-sensor [ 44 ] integration, as well as related magnetic flux concentrators [ 45 ] or magnetic sensors [ 46 ], were also demonstrated in GaN technologies. External current sensors or two-chip solutions (GaN and Si) are also often used and investigated for GaN power electronics [ 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 , 55 , 56 , 57 ].…”