mc3phacvp Freescale Semiconductor, Inc, mc3phacvp Datasheet - Page 8

• Manufacturer Part Number: mc3phacvp
• Description: Mc3phac Motor Control Unit
• Manufacturer: Freescale Semiconductor, Inc

Introduction
Introduction
The MC3PHAC is a high-performance intelligent controller designed specifically to meet the requirements
for low-cost, variable-speed, 3-phase ac motor control systems. The device is adaptable and
configurable, based on its environment. Constructed with high-speed CMOS (complementary metal-
oxide semiconductor) technology, the MC3PHAC offers a high degree of performance and ruggedness
in the hostile environments often found in motor control systems.
The device consists of:
The serial communications interface is used in a mode, called PC master software mode, whereby control
of the MC3PHAC is from a host or master personal computer executing PC master software or a
microcontroller emulating PC master software commands. In either case, control via the internet is
feasible.
Included in the MC3PHAC are protective features consisting of dc bus monitoring and a system fault input
that will immediately disable the PWM module upon detection of a system fault.
Included motor control features include:
Features
3-Phase Waveform Generation — The MC3PHAC generates six PWM signals which have been
modulated with variable voltage and variable frequency information in order to control a 3-phase ac motor.
A third harmonic signal has been superimposed on top of the fundamental motor frequency to achieve full
bus voltage utilization. This results in a 15 percent increase in maximum output amplitude compared to
pure sine wave modulation.
The waveform is updated at a 5.3 kHz rate (except when the PWM frequency is 15.9 kHz), resulting in
near continuous waveform quality. At 15.9 kHz, the waveform is updated at 4.0 kHz.
DSP Filtering — A 24-bit IIR digital filter is used on the SPEED input signal in standalone mode, resulting
in enhanced speed stability in noisy environments. The sampling period of the filter is 3 ms (except when
the PWM frequency is 15.9 kHz) and it mimics the response of a single pole analog filter having a pole at
0.4 Hz. At a PWM frequency of 15.9 kHz, the sampling period is 4 ms and the pole is located at 0.3 Hz.
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6-output pulse-width modulator (PWM)
4-channel analog-to-digital converter (ADC)
Phase-lock loop (PLL) based system oscillator
Low-power supply voltage detection circuit
Serial communications interface (SCI)
Open loop volts/Hertz speed control
Forward or reverse rotation
Start/stop motion
System fault input
Low-speed voltage boost
Internal power-on reset (POR)
MC3PHAC Monolithic Intelligent Motor Controller, Rev. 2
Freescale Semiconductor