The INA220 is a current shunt and power monitor with an I2C- or SMBUS-compatible interface. The INA220 monitors both shunt drop and supply voltage. A programmable calibration value, combined with an internal multiplier, enables direct readouts in amperes. An additional multiplying register calculates power in watts. The I2C- or SMBUS-compatible interface features 16 programmable addresses. The separate shunt input on the INA220 allows it to be used in systems with low-side sensing. The INA220 is available in two grades: A and B. The B grade version has higher accuracy and higher precision specifications. The INA220 senses across shunts on buses that can vary from 0 to 26 V, useful for low-side sensing or CPU power supplies. The device uses a single 3- to 5.5-V supply, drawing a maximum of 1 mA of supply current. The INA220 operates from –40°C to 125°C.