HIGH-PRECISION CROSS-CORE CLOSED-LOOP SINGLE POWER SUPPLY ELECTRONIC CIRCUIT FOR HALL CURRENT SENSOR

摘要

A high-precision cross-core closed-loop single power supply electronic circuit for a Hall current sensor belongs to the field of electronic circuitry for a Hall current sensor. A current to be measured less than 50 A is output using a heavy current, and one of rail-to-rail input/output dual operational amplifiers (1/2A1) amplifies the output voltages of Hall elements (H1, H2) to drive a secondary coil (N_S), and the other amplifier is used as an I/V converter; a current to be measured greater than 50 A is output using a heavy current, and one of rail-to-rail output dual operational amplifiers (1/2A1) amplifies the output voltages of Hall elements (H1, H2) to form an H-bridge with the other amplifier so as to drive the secondary coil (N_S); a secondary current (I_S) is sampled and then differential amplification output is performed thereon using a rail-to-rail input/output dual operational amplifier (1/2A2); variable voltage references (VZ1, VZ2) are used to offset the amplifiers and Hall elements; a reference voltage end (V_R) can both output and externally control changes; and a plurality of Hall elements use a constant voltage operation mode to calculate the arithmetic mean value of the output voltages thereof. The Hall current sensor has a larger measurement range and higher precision.