Motorola M68HC08 - Manual (Page 72)

Hardware Design
Designer Reference Manual DRM028 — Rev 0
72 Hardware Design MOTOROLA
4.6 Low-Voltage Hardware Set Components
4.6.1 3-Ph AC/BLDC Low Voltage Power Stage
Motorola’s embedded motion control series low-voltage (LV) brushless
DC (BLDC) power stage is designed to run 3-ph. BLDC and PM
Synchronous motors. It operates from a nominal 12-volt motor supply,
and delivers up to 30 amps of rms motor current from a dc bus that can
deliver peak currents up to 46 amps. In combination with one of
Motorola’s embedded motion control series control boards, it provides a
software development platform that allows algorithms to be written and
tested, without the need to design and build a power stage. It supports a
wide variety of algorithms for controlling BLDC motors and PM
Synchronous motors.
Input connections are made via 40-pin ribbon cable connector J13.
Power connections to the motor are made with fast-on connectors J16,
J17, and J18. They are located along the back edge of the board, and
are labeled Phase A, Phase B, and Phase C. Power requirements are
met with a 12-volt power supply that has a 10- to 16-volt tolerance.
Fast-on connectors J19 and J20 are used for the power supply. J19 is
labeled +12V and is located on the back edge of the board. J20 is
labeled 0V and is located along the front edge. Current measuring
circuitry is set up for 50 amps full scale. Both bus and phase leg currents
are measured. A cycle by cycle overcurrent trip point is set at 46 amps.
Voltage Constant K
e
— 8.4 — V/kRPM
Winding Resistance R
t
— 2.8 — Ω
Winding Inductance L — 8.6 — mH
Continuous Current I
cs
— — 2 A
Peak Current I
ps
— — 5.9 A
Inertia J
m
— 0.075 — kgcm
2
Thermal Resistance — — 3.6 °C/W
Table 4-5. Characteristics of the BLDC motor
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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