Three-Input Type Single-Chip Inverter IC including a Function to Generate Six Signals and Dead Time

We have developed a three-input type single-chip inverter IC for the sine wave drive system in air-conditioner fan motors. The inverter IC integrates a function to generate six signals and dead time. This function generates short dead times, typically 1.5us, to suppress distortion of motor current waveforms. These short dead-times are sufficient to prevent upper and lower arm short-circuits because production variations are reduced by the characteristics of the three-input type single-chip inverter IC. Moreover, the three-input type prevents upper and lower arm short-circuits caused by abnormal input signals, and reduces the number of lines on a circuit board to connect a microcomputer with the inverter IC.