US 12,228,595 B2
Apparatus and method for measuring a current flowing through a PWM-controlled inductive load
Ulrich Joos, Nonnenhorn (DE); and Erwin Kessler, Bad Saulgau (DE)
Assigned to Conti Temic microelectronic GmbH, Nuremberg (DE)
Appl. No. 17/627,301
Filed by Conti Temic microelectronic GmbH, Nuremberg (DE)
PCT Filed Jul. 14, 2020, PCT No. PCT/EP2020/069818
§ 371(c)(1), (2) Date Jan. 14, 2022,
PCT Pub. No. WO2021/009147, PCT Pub. Date Jan. 21, 2021.
Claims priority of application No. 10 2019 210 566.1 (DE), filed on Jul. 17, 2019.
Prior Publication US 2022/0260615 A1, Aug. 18, 2022
Int. Cl. G01R 19/165 (2006.01); G01K 13/00 (2021.01); G01R 19/10 (2006.01); H02M 1/00 (2007.01); H02M 3/158 (2006.01); H02P 7/03 (2016.01)
CPC G01R 19/16571 (2013.01) [G01K 13/00 (2013.01); G01R 19/10 (2013.01); H02M 1/0009 (2021.05); H02M 3/158 (2013.01); H02P 7/04 (2016.02)] 15 Claims
OG exemplary drawing
 
1. An apparatus for measuring an electric current flowing through an inductive load which is energized by a half-bridge circuit having at least two semiconductor switches, wherein the semiconductor switches are switched on and off in a complementary manner in accordance with a PWM method, the apparatus comprising:
a monitoring device configured to determine switched-on states and switched-off states of at least one of the at least two semiconductor switches,
a synchronous measurement amplifier, which is controlled by the monitoring device and configured to measure a voltage drop present at the semiconductor switch during the determined switched-on state of the semiconductor switch and to multiply it so as to form a multiplied voltage, a synchronous voltage follower, which is controlled by the monitoring device and generates a voltage signal which is characteristic of the current in the inductive load and which in the switched-on state of the semiconductor switch follows the multiplied voltage and in the switched-off state of the semiconductor switch remains substantially constant or decreases in accordance with a predefined profile,
wherein the half-bridge circuit comprises a plurality of half-bridges each having two semiconductor switches; and
a controllable selection device by which one of the at least two semiconductor switches can be selected for measuring the current flowing through the inductive load.