A low-power sensorless inverter controller is designed for brushless DC (BLDC) motors without using any Hall sensor. A back-EMF (back-electromotive force) estimation method is adopted to detect the commutation moment for rotation control of the brushless DC motors. The position of the rotor can be precisely estimated by measuring the back-EMF as well as the zero-crossing points. The proposed controller is low power and low cost because of not using expensive power consuming Hall sensors. The proposed sensorless inverter controller is integrated in a standard mixed-signal single-poly, and six metal 0.18-μm CMOS process. Keywords—sensorless, brushless, motor, low-power, inverter, BLDC.