MC3PHAC Motorola, MC3PHAC Datasheet - Page 21

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

Standalone Operation
MOTOROLA
If the VBOOST_MODE pin is high when the MC3PHAC is powered up, or after
a reset, the MC3PHAC enters standalone mode. In this mode of operation, the
functionality of many of the MC3PHAC pins change so that the device can
control a motor without requiring setup information from an external master.
When operated in standalone mode, the MC3PHAC will drive certain pins
corresponding to parameters which must be specified, while simultaneously
monitoring the response on other pins.
In many cases, the parameter to be specified is represented as an analog
voltage presented to the MUX_IN pin, while certain other pins are driven low.
In so doing, the MC3PHAC can accommodate an external analog mux which
will switch various signals on the MUX_IN pin when the signal select line goes
low. All signals must be in a range between 0 V and V
alternative, an external passive network can be connected to each of the
parameter select output pins and the MUX_IN pin, as shown in
The Thevenin equivalent impedance of this passive network as seen by the
MUX_IN pin is very important and should be in the range of 5 k
the resistance is too high, leakage current from the input/output (I/O) pins will
cause an offset voltage that will affect the accuracy of the reading. If the
resistance is too low, the parameter select pins will not be able to sink the
required current for an accurate reading. Using a pullup resistor value of 6.8 k
(as indicated in
of the corresponding pulldown resistor value is shown in
Figure
The START input pin is debounced internally and a switch can be directly
accommodated on this pin. The input is level sensitive, but a logic 1 level must
exist on the pin before a logic 0 level will be processed as a start signal. This
will prevent an accidental motor startup in the event of the MC3PHAC being
powered up, where the switch was left in the start position.
The FWD input pin is debounced internally and can directly accommodate a
switch connection. The input is also level sensitive.
Figure 8
PWMPOL_BASEFREQ input pin. For proper operation, one and only one
jumper connection can be made at any given time.
and base frequency selections as a function of the jumper connection.
Freescale Semiconductor, Inc.
For More Information On This Product,
11, and
shows the jumper arrangement connected to the
3-Phase AC Motor Controller
Go to: www.freescale.com
Figure
Table
4.
8), the resulting value for each parameter as a function
Table 3
REF
Figure
. As an economical
shows the polarity
Figure
9,
to 10 k . If
Figure
MC3PHAC/D
Operation
8.
10,
21