Microcontrollers with Inverter Motor Control Circuit (PMD)

Since the 1990’s Toshiba has been developing 8-bit microcontrollers containing a Programmable Motor Driver (PMD) specifically tailored to inverter motor control applications. Toshiba is dedicated to provide flexible motor control to realize enhanced efficiency and quiet operation.

The PMD is Toshiba's original inverter control circuit for three-phase motors. With built-in hardware that links motor drive signals with feedback signals from the motor, the PMD can realize motor control with less load imposed on the CPU. This approach makes it possible to control sine wave drive with the amount of software processing comparable to that for square wave drive.

Originally developed for home appliances requiring inverter control, Toshiba’s PMD microcontrollers are also expanding into the automotive motor control field.

Applications

Air-conditioners
Refrigerators
Washing machines

Basic Concept behind Toshiba’s PMD Microcontrollers

The basic concept behind Toshiba’s PMD microcontrollers is to make a maximum use of hardware for routine tasks and to use software only for non-routine processing. This enables customers to control sine wave drive with a software interrupt period (upon every position detection) comparable to that for square wave drive.

Sine Wave Drive with an Interrupt Period Comparable to Square Wave Drive

Key Features

Sine wave drive
Position detection (sampling during the PWM on period, suspending sampling immediately after PWM is turned on)
Motor control timer and timer capture
Three-phase PWM output
Automatic generation of sine wave duty (PMDRAM, automatic duty calculation)
Overload protection (CL pin)
Emergency protection (EMG pin)
Automatic commutation and automatic position detection start (mode timer, capture)
PWM-sync AD conversion for measuring motor load