Hardware Design
Low-Voltage Hardware Set Components
DRM028 — Rev 0
Designer Reference Manual
MOTOROLA
Hardware Design
73
The LV BLDC power stage has both a printed circuit board and a power
substrate. The printed circuit board contains MOSFET gate drive
circuits, analog signal conditioning, low-voltage power supplies, and
some of the large passive power components. This board also has a
68HC705JJ7 microcontroller used for board configuration and
identification. All of the power electronics that need to dissipate heat are
mounted on the power substrate. This substrate includes the power
MOSFETs, brake resistors, current-sensing resistors, bus capacitors,
and temperature sensing diodes.
Figure 4-5
shows a block diagram.
Figure 4-6. Block Diagram
4.6.1.1 Electrical Characteristics of the 3-Ph BLDC Low Voltage Power Stage
The electrical characteristics in
Table 4-6
apply to operation at 25
°
C with
a 12-Vdc supply voltage.
POWER
INPUT
BIAS
POWER
BRAKE
MOSFET
GATE
PHASE CURRENT
PHASE VOLTAGE
BUS CURRENT
BUS VOLTAGE
MONITOR
ZERO CROSS
BACK-EMF SENSE
BOARD
ID BLOCK
SIGNALS
TO/FROM
CONTROL
BOARD
POWER MODULE
DRIVERS
MOTOR
TO
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Freescale Semiconductor, Inc.
For More Information On This Product,
Go to: www.freescale.com
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