US 12,273,030 B2
Current sensing circuit and corresponding DC-DC converter
Stefano Ramorini, Milan (IT)
Assigned to STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed by STMicroelectronics S.r.l., Agrate Brianza (IT)
Filed on Oct. 11, 2022, as Appl. No. 17/963,534.
Claims priority of application No. 102021000026927 (IT), filed on Oct. 20, 2021.
Prior Publication US 2023/0127446 A1, Apr. 27, 2023
Int. Cl. H02M 3/158 (2006.01); G01R 15/14 (2006.01); H02M 1/00 (2007.01)
CPC H02M 3/158 (2013.01) [G01R 15/146 (2013.01); H02M 1/0009 (2021.05)] 17 Claims
OG exemplary drawing
 
1. A circuit, comprising:
a first transistor having a source terminal configured to be selectively coupled to a first terminal of an electronic power transistor switch through a first resistor;
a second transistor having a source terminal configured to be selectively coupled to a second terminal of said electronic power transistor switch through a second resistor;
wherein said first transistor and said second transistor have same dimensions;
a current mirror circuit coupled between a first node and a second node, wherein a drain terminal of said first transistor is connected to said first node and a drain terminal of said second transistor is connected to said second node, the current mirror circuit being configured to sink a current from said first node equal to a current flowing through said second transistor;
a biasing circuit coupled to said first transistor and to said second transistor, the biasing circuit configured to provide a same biasing voltage to a control terminal of said first transistor and to a control terminal of said second transistor; and
an output resistor having a first terminal directly connected to said first node and a second terminal coupled to a reference voltage node;
wherein an output voltage signal at said first node depends on a voltage between the first and second terminals of the electronic power transistor switch amplified by a constant gain set by a ratio of a resistance value of the output resistor to a resistance value of the first resistor, said output voltage signal being indicative of positive and negative current flowing through said electronic power transistor switch.