HIGH PERFORMANCE BRUSHLESS DC MOTOR DRIVER
BC20 • BC20A
M I C R O T E C H N O L O G Y
HTTP://WWW.APEXMICROTECH.COM
(800) 546-APEX
(800) 546-2739
FEATURES
• 40V TO 450V MOTOR SUPPLY
• 20A CONTINUOUS AND 40A PEAK OUTPUT CURRENT
• OPERATION WITH 10.8V TO 16V VCC, ALLOWING
NOMINAL 12V OR 15V VCC SUPPLIES
• THREE PHASE FULL BRIDGE OPERATION WITH 2 OR
4 QUADRANT PWM
• AUTOMATIC BRAKING WHEN USING 2 QUADRANT PWM
• THERMAL PROTECTION
• ANTI SHOOT THROUGH DESIGN
• 25KHZ INTERNALLY SET PWM FREQUENCY, WHICH MAY
BE LOWERED WITH EXTERNAL CAPACITORS
• SELECTABLE 60° OR 120° COMMUTATION SEQUENCES
• COMMUTATION TRANSITIONS OUTPUT FOR DERIVING
SPEED CONTROL
• MAY BE USED OPEN LOOP, OR WITHIN A
FEEDBACK LOOP
• ANALOG MOTOR CURRENT MONITOR OUTPUT, MAY BE
USED FOR TORQUE CONTROL OR FOR TRANSCONDUC-
TANCE AMPLIFIER DRIVE.
DESCRIPTION
The BC20 Brushless DC Motor Controller provides
the necessary functions to control conventional 3-phase
brushless DC motors in an open loop or closed loop
system. The BC20 can control larger motors requiring up
to 4.5kW input power.
The controller drives the motor, generates the PWM,
decodes the commutation patterns, multiplexes the current
sense, and provides error amplification. Operation with
either 60° or 120° commutation patterns may be selected
with a logic input.
Current sense multiplexing is used to make the current
monitor output always proportional to the active motor
APPLICATIONS
coils current. Therefore the current monitor output may
be used in generating transconductance drive for easy
• 3 PHASE BRUSHLESS MOTOR CONTROL
servo compensation.
Figure 1: Block diagram
The controller may generate 4-quadrant PWM for
applications requiring
2Q
VCC
SSC
HV
HV
continuous transition
20
2
9
18
through zero veloc-
V+
OE
19
ity, or 2 quadrant
OUT 1
TOP DRIVE 1
1/2
HS1
6
PWM for electrically
10
BRIDGE
BOTTOM DRIVE 1
1
HS2
7
quieter operation in
S1
COMMUTATION
DECODE
13
HS3
8
unidirectional appli-
LOGIC
120
22
BRIDGE
cations. Direction
CONTROL
REV
21
LOGIC
of rotation may be
V+
REF IN
23
reversed in 2-quad-
PWM
rant mode by using
OUT 2
TOP DRIVE 2
+
1/2
COMPARATOR
BRIDGE
11
+
the reverse com-
BOTTOM DRIVE 2
2
∑
X10
∑
X10
S2
mand input. When in
PWM
–
–
15
2-quadrant mode if
FB
24
the motor is stopped
V+
TEMP
SENSING
or
decelerating
dynamic braking is
SHUTDOWN
OVERTEMP
OUT 3
TOP DRIVE 3
1/2
automatically
12
BRIDGE
BOTTOM DRIVE 3
3
applied. In this way
S3
14
deceleration profiles
may be followed even
POWER
CURRENT
FAULT OVERCURRENT
when using 2-quad-
SENSING
LOGIC
PWM
HV RTN
SIGNAL
rant PWM.
HV RTN
OSCILLATOR
16
CONDITIONING
5
MOTOR I
4
TORQUE
CT
3
17
FAULT
GROUND
1
APEX MICROTECHNOLOGY CORPORATION
• TELEPHONE (520) 690-8600 • FAX (520) 888-3329 • ORDERS (520) 690-8601 • EMAIL prodlit@apexmicrotech.com
1
CIRRUS [ CIRRUS LOGIC ]
