MC3PHAC Motorola, MC3PHAC Datasheet - Page 24

• Manufacturer Part Number: MC3PHAC
• Description: 3-Phase AC Motor Controller
• Manufacturer: Motorola

MC3PHAC/D
Standalone Application Example
PC Master Software Operation
Introduction to PC Master Host Software
24
Figure 12
standalone mode. Resistor values and jumpers have been selected to provide
the following performance:
The MC3PHAC is compatible with Motorola’s PC master host software serial
interface protocol. Communication occurs over an on-chip UART, on the
MC3PHAC at 9600 baud to an external master device, which may be a
microcontroller that also has an integrated UART or a personal computer via a
COM port. With PC master software, an external controller can monitor and
control all aspects of the MC3PHAC operation.
When the MC3PHAC is placed in PC master software mode, all control of the
system is provided through the integrated UART, resident on the MC3PHAC.
Inputs such as START, FWD, SPEED, ACCEL, MUX_IN, and
PWMPOL_BASEFREQ have no controlling influence over operation of the
system. Even though the SPEED, START, and FWD inputs are disabled while
the system is in PC master software mode, through PC master software, it is
possible to monitor the state of those inputs.
1. Base frequency of 60 Hz and positive PWM polarity (from
2. PWM frequency resistor 3.9 k , which implies 10.582 kHz from
3. Dead-time resistor = 5.1 k , which implies 4.5 s (from
4. Fault retry time resistor = 8.2 k , which implies 32.8 seconds (from
5. Voltage boost resistor = 12 k , which implies 25.5 percent (from
6. The wiper of the acceleration potentiometer is set at
7. Crystal/resonator capacitor values are typical values from the
Freescale Semiconductor, Inc.
For More Information On This Product,
Table
Figure
Figure
2.5 V = 64 Hz/second acceleration rate (from the
description on
been a resistor divider. If a resistor divider is used in place of the
acceleration potentiometer, keep the total resistance of the two resistors
less than 10 k . Always use 4.7k in series with the center of the
acceleration voltage divider resistors, connected to the ACCEL (pin 27)
as shown in the application example,
manufacturer. Refer to the manufacturers data for actual values.
shows an application example of the MC3PHAC, configured in
3-Phase AC Motor Controller
4). (5v/(3.9k + 6.8k))*3.9k = 1.82 volts
Go to: www.freescale.com
10).
11).
page
14.) The potentiometer, in this case, could have
Figure
12.
Acceleration Control
Figure
Table
MOTOROLA
9)
3)