一种面向电机驱动的集成双向电流检测电路设计OA

In motor drive applications,to address the problems of high power loss in current detection using external discrete resistors and the complex bidirectional current sampling architecture of traditional integrated current sampling circuits,a bidirectional current sampling integrated current detection circuit for motor drives was designed.The circuit adopted a sensing unit matched with the main power transistor structure to achieve current sampling,and we designed a bidirectional current detection module based on a source-supply architecture.To tackle the drawback of large quiescent current in traditional bidirectional detection structures,a common-mode feedback circuit was introduced to regulate the quiescent current of the push-pull output stage and optimize the stability of the signal chain.Designed with a standard 0.18 μm BCD process,the circuit achieved an absolute error of less than±3.2%between the detection signal and the inductor current,with a detection linearity of 0.3%under full PVT conditions.Moreover,the circuit operated at up to 2.73 MHz when the supply voltage was between 3.5 V and 5.2 V,and exhibited good power supply rejection ratio(PSRR)and common-mode rejection ratio(CMRR),making it suitable for brushless motor drive scenarios.