Current Sensor Type: ACS758ECB-200B, with 100 μΩ internal conductor resistance;Operating voltage: 3.3-5V; linearity K: 10mV / A detectable current (AC or DC) range Ia: -200A ~ 200A; output voltage formula: = OU1 OU2 = the VCC / 2 + Ia * K = the VCC / 2 + (0.01 V * Ia); wherein, OU2 is OU1 through the voltage follower output buffer, can tell the microcontroller a / D channel better impedance