MIL-PRF-38534 AND 38535 CERTIFIED FACILITY
10 AMP, 200V, 3 PHASE
MOSFET BRUSHLESS
MOTOR CONTROLLER
FEATURES:
200 Volt Motor Supply Voltage
10 Amp Output Switch Capability
Shoot-Through/Cross Conduction Protection
Hall Sensing and Commutation Circuitry on Board
"Real" Four Quadrant Torque Control Capability
Good Accuracy Around the Null Torque Point
Hermetic Package Design for High Voltage Isolation Plus Good Thermal Transfer
60°/ 120º Phasing Selectable
Contact MSK for MIL-PRF-38534 Qualification Status
4324
DESCRIPTION:
The MSK4324 is a complete 3 Phase MOSFET Bridge Brushless Motor Control System in a convenient isolated baseplate
package. The device is capable of 10 amps of output current and 200 volts of DC bus voltage. It has the normal features for
protecting the bridge. Included is all the bridge drive circuitry, hall sensing circuitry, commutation circuitry and all the current
sensing and analog circuitry necessary for closed loop current mode (torque) control. When PWM'ing, the transistors are
modulated in locked anti-phase (complementary) mode for the tightest control and the most bandwidth. Provisions for ap-
plying different compensation schemes are included. The MSK4324 has good thermal conductivity of the MOSFET's due to
a hermetic isolated package design that allows direct heat sinking of the device without insulators.
BLOCK DIAGRAM
TYPICAL APPLICATIONS
3 Phase Brushless DC Motor Control
Servo Control
Fin Actuator Control
Gimbal Control
AZ-EL Control
1
2
3
4
5
6
7
8
9
10
11
REFOUT
HALL A
HALL B
HALL C
60/120
BRAKE
CLOCK SYNC
DIS
GND
NC
NC
PIN-OUT INFORMATION
12
13
14
15
16
17
18
19
20
21
22
E/A OUT
E/A-
GND
+CURRENT COMMAND
-CURRENT COMMAND
+15 VIN
CURRENT MONITOR
-15 VIN
NC
NC
ILIMIT ADJUST
23
24
25
26
27
28
29
30
31
32
33
GND
NC
NC
LGND
RTN
RTN
CVS
CVS
CØ
CØ
CV+
34
35
36
37
38
39
40
41
42
43
BVS
BVS
BØ
BØ
BV+
AVS
AVS
AØ
AØ
AV+
1
8548-23 Rev. G 1/15
ABSOLUTE MAXIMUM RATINGS
7
High Voltage Supply
9
200V
Current Command Input
±13.5V
Logic Inputs
-0.2V to REFOUT
REFOUT External Load
15 mA
E/A OUT External Load
5 mA
Clock SYNC Input
-0.2V to +15V
Continuous Output Current
10 Amps
Continuous Output Current @ 125°C Case
5 Amps
Peak Output Current
15 Amps
Rθ
JC
Thermal Resistance (Output Switches@125°C) 0.5°C/W
T
ST
Storage Temperature Range
10
-65°C to +150°C
T
LD
Lead Temperature Range
(10 Seconds)
+300°C
T
C
Case Operating Temperature
MSK4324
-40°C to +85°C
MSK4324H
-55°C to +125°C
T
J
Junction Temperature
+150°C
ELECTRICAL SPECIFICATIONS
Parameter
INPUT CURRENT
+15 VIN
Output PWM'ing
Current Command=0 Volts
Output PWM'ing
Current Command=0 Volts
Free Running
Test Conditions
Group A
Subgroup
4 5
MSK4324H
5
Min.
Typ.
Max.
-
-
-
-
-
-
14
14
-
12.5
10
Clock+0
MSK4324
2
Min. Typ. Max.
-
-
-
-
-
-
14
-
-
12.5
10
89
-
-
24
-
-
17
-
-
-
-
-
-
-
-
-
6.25
-
-
1.0
-
0
1.0
-
-
-
8
6.5
275
5
-
-
-
220
3
-
150
-
-
60
-
-
20
-
2.5
-
90
Clock+3
Units
-15 VIN
PWM Clock Frequency
CLOCK SYNC INPUT
V
IL
1
V
IH
1
Duty Cycle 1
Sync Frequency
1
2
3
1
2
3
4
5,6
-
-
-
-
-
-
-
-
1
-
-
4
5,6
1
4
5,6
-
-
-
-
-
1
-
-
-
-
-
-
89
83
106
24
26
23
17
17
-
-
-
-
-
-
-
-
6.25
-
-
1.0
1.0
0
1.0
1.0
-
-
8
6.5
275
5
-
-
-
220
3
-
150
150
150
60
60
60
20
20
2.5
-
90
mA
mA
mA
mA
mA
mA
KHz
KHz
V
V
%
KHz
V
V
V
V
V
V
mA
A/V
A/V
mA
V/A
V/A
V
V
V/µsec
MHz
V/mV
Amps
V
V
mA
nsec
µsec
Ω
1
LOGIC INPUTS
(Hall A,B,C,Brake,60°/120°)
V
IL
1
V
IH
1
DIS
V
IL
1
V
IH
1
REFERENCE
ANALOG SECTION
Current Command Input Range 1
Current Command Input Current 1
Transconductance 6
Offset Current
Current Monitor 6
Current Motor Voltage Swing
Error Amp
E/A OUT Voltage Swing 1
Slew Rate 1
Gain Bandwidth Product 1
Large Signal Voltage Swing 1
Current Limit Adjust
OUTPUT SECTION
Voltage Drop Across Bridge
1
(1 Upper & 1 Lower)
Leakage Current 1
T
RR
1
Dead Time 1
Drain-Source On Resistance 1 8
Clock+3 Clock+0
-
3.0
-
12.5
5.82
-13.5
-
0.90
0.85
-25
0.90
0.85
-12
-12
6.8
-
175
4
-
-
-
-
-
-
0.8
-
2.5
-
6.57
+13.5
1.5
1.1
1.15
+25
1.1
1.15
+12
+12
-
-
-
6
TBD
TBD
1
330
-
0.151
-
3.0
-
12.5
5.82
-13.5
-
0.85
-
-50
0.85
-
-12
-12
6.8
-
175
4
-
-
-
-
-
-
0.8
-
2.5
-
6.57
+13.5
1.5
1.15
-
+50
1.15
-
+12
+12
-
-
-
6
TBD
-
1
330
-
0.151
@ 15mA Load
Current Command=0 Volts
@ 5mA Load
@ 5mA Load
Pin 22 1.92KΩ to GND
5 Amps @ 125°C T
C
Whole Bridge
All Switches off, 100V,150°C
@ 5 Amps, 150°C Junction
NOTES:
1
2
3
4
5
6
7
8
9
10
Guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference only.
Industrial grade devices shall be tested to subgroups 1 and 4 unless otherwise specified.
Military grade devices ("H" suffix) shall be 100% tested to subgroups 1,2,3 and 4.
Subgroups 5 and 6 testing available upon request.
Subgroup 1,4
TA=TC=+25°C
2,5 TA=TC=+125°C
3,6 TA=TC=-55°C
Measurements do not include offset current at 0V current command.
Continuous operation at or above absolute maximum ratings may adversly effect the device performance and/or life cycle.
This is to be used for MOSET thermal calculations only.
When applying power to the device, apply the low voltage followed by the high voltage or alternatively, apply both at the same time.
Do not apply high voltage without low voltage present.
Internal solder reflow temperature is 180°C, do not exceed.
2
8548-23 Rev. G 1/15
APPLICATION NOTES
AV+, BV+, CV+ -
are the power connections from the hybrid to the
bus. The pins for each phase are brought out separately and must
be connected together to the V+ source externally. The external
wiring to these pins should be sized according to the RMS current
required by the motor. These pins should be bypassed by a high
quality monolithic ceramic capacitor for high frequencies and enough
bulk capacitance for keeping the V+ supply from drooping.
Note: this is a power sequence sensitive part. Either turn on all supplies
simultaneously or provide ±15V first, then V+ voltages.
AØ, BØ & CØ -
are the connections to the motor phase windings
from the bridge output. The wiring to these pins should be sized
according to the current required by the motor. There are no short
circuit provisions for these outputs. Shorts to V+ or ground from
these pins must be avoided or the bridge will be destroyed.
AVS, BVS, CVS -
are the return pins on the bottom of each half
bridge. They are brought out separately and should be connected
together externally to allow the current from each half bridge to flow
through the sense resistor. The wiring on these pins should be sized
according to the current requirements of the motor.
RTN -
is the power return connection from the module to the bus.
All ground returns connect to this point from internal to the mod-
ule in a star fashion. All external ground connections to this point
should also be made in a similar fashion. The V+ capacitors should
be returned to this pin as close as possible. Wire sizing to this pin
connection should be made according to the required current.
LGND -
is an isolated ground connection to the RTN pin of the
hybrid that is connected internally. For any circuitry that needs to
be connected to the RTN pin without the influence of current flow
through RTN should be connected at this point.
GND -
is a ground pin that connects to the ground plane for all low
powered circuitry inside the hybrid.
+15 VIN -
is the input for applying +15 volts to run the low power
section of the hybrid. This pin should be bypassed with a 10 µF
capacitor and a 0.1 µF capacitor as close to this pin as possible.
Note: this is a power sequence sensitive part. Either turn on all supplies
simultaneously or provide ±15V first, then V+ voltages.
-15 VIN -
is the input for applying -15 volts to run the low power
section of the hybrid. This pin should be bypassed with a 10 µF
capacitor and a 0.1 µF capacitor as close to this pin as possible.
Note: this is a power sequence sensitive part. Either turn on all supplies
simultaneously or provide ±15V first, then V+ voltages.
CURRENT COMMAND (+,-) -
are differential inputs for controlling
the module in current mode. Scaled at ±1 amp per volt of input
command, the bipolar input allows both forward and reverse current
control capability regardless of motor commutation direction. The
maximum operational command voltage should be ±10 volts for
±10 amps of motor current.
MSK4324 PIN DESCRIPTIONS
CURRENT MONITOR -
is a pin providing a current viewing signal
for external monitoring purposes. This is scaled at ±1 amp of motor
current per volt output, up to a maximum of ±10 volts, or ±10 amps.
As ±10 amps is exceeded, the peaks of the waveform may become
clipped as the rails of the amplifiers are reached. This voltage is
typically ±12.5 volts, equating to ±12.5 amps of current peaks. In
DIS mode, the CURRENT MONITOR output may rail positive or
negative, depending on internal bias currents. When re-enabled,
this output will resume expected operation.
E/A OUT -
is the current loop error amp output connection. It is
brought out for allowing various loop compensation circuits to be
connected between this and E/A-. See "anti-windup" discussion
later on in this section.
E/A- -
is the current loop error amp inverting input connection. It is
brought out for allowing various loop compensation circuits to be
connected between this and E/A OUT. See "anti-windup" discussion
later on in this section.
CLOCK SYNC
- is an input for synchronizing to an external clock.
The sync circuit will trigger on the edges of the applied clock and
effectively shorten the period of the internal oscillator on each cycle.
The frequency can be increased from a free running 14 KHz to 20
KHz maximum. The clock applied shall be 15 volts amplitude with
at least a 10% duty cycle.
REFOUT -
is a 6.25 volt regulated output to be used for powering
the hall devices in various motors. Up to 15 mA of output current is
available.
HALL A, B & C -
are the hall input pins from the hall devices in the
motor. These pins are internally pulled up to 6.25 volts. The halls
can reflect a 120/240 degree commutation scheme or a 60/300
degree scheme.
IN
BRAKE -
is a pin for commanding the output bridge into a motor
BRAKE mode. When pulled low, normal operation commences.
When pulled high, the 3 high side bridge switches turn off and the
3 low side bridge switches turn on, causing rapid deceleration of the
motor and will cease motor operation until pulled high again. Logic
levels for this input are TTL compatible. It is necessary to toggle
ON and OFF BRAKE after power up before normal operation can
begin. This is necessary because of the bootstrap high-side power
supplies for each phase. These are not continuous high-side sup-
plies and need to be refreshed by turning on the low side switches
momentarily with the BRAKE. It is internally pulled high.
DIS -
is a pin for externally disabling the output bridge. A 15V
CMOS logic high will enable the bridge and a 15V CMOS logic low
will disable it. After using the DIS pin, the BRAKE must be cycled
ON and OFF before normal operation will begin. This is due to the
bootstrap high-side supplies needing refreshing.
60/120 -
is a pin fpr selecting the orientation of the commutation
sheme of the motor. A high state will produce 60/300 degree
commutation, whereas a low state will produce 120/240 degree
commutation. Logic levels for this input are TTL compatible. It is
internally pulled high.
ILIMIT ADJUST-
is a pin for externally adjusting the current limit
point. By placing a resistor to ground from this pin, a voltage divider
is created and the current limit will be lowered. Without an external
resistor, the current limit is set at 13 Amps.
3
8548-23 Rev. G 1/15
APPLICATION NOTES CONTINUED
COMMUTATION TRUTH TABLE
1
0
X
=
=
=
High Level
Low Level
Don't Care
H
L
-
=
=
=
SOURCE
SINK
OPEN
NOTE:
Because of the true 4 quadrant method of output switching,
the output switches will PWM between the I
COMMAND
POSITIVE
and I
COMMAND
NEGATIVE states, with the average percentage
based on I
COMMAND
being a positive voltage and a negative
voltage. With a zero voltage I
COMMAND
, the output switches will
modulate with exactly a 50% duty cycle between the
I
COMMAND
POSITIVE and I
COMMAND
NEGATIVE states.
CURRENT (A)
2.0
4.0
6.0
8.0
10.0
RESISTOR (KΩ)
0.56
1.37
2.61
4.77
9.48
4
8548-23 Rev. G 1/15
APPLICATION NOTES CONTINUED
BUS VOLTAGE FILTER CAPACITORS
The size and placement of the capacitors for the DC bus has a direct bearing on the amount of noise filtered and also on the size and
duration of the voltage spikes seen by the bridge. What is being created is a series RLC tuned circuit with a resonant frequency that is
seen as a damped ringing every time one of the transistors switches. For the resistance, wire resistance, power supply impedance and
capacitor ESR all add up for the equivalent lumped resistance in the circuit. The inductance can be figured at about 30 nH per inch from
the power supply. Any voltage spikes are on top of the bus voltage and the back EMF from the motor. All this must be taken into account
when designing and laying out the system. If everything has been minimized, there is another solution. A second capacitance between
5 and 10 times the first capacitor and it should either have some ESR or a resistor can be added in series with the second capacitor to
help damp the voltage spikes.
Be careful of the ripple current in all the capacitors. Excessive ripple current, beyond what the capacitors can handle, will destroy the
capacitors.
REGULATED VOLTAGE FILTER CAPACITORS
It is recommended that about 10 µF of capacitance (tantalum) for bypassing the + and -15V regulated outputs be placed as close to
the module pins as practical. Adding ceramic bypass capacitors of about 0.1 µF or 1 µF will aid in suppressing noise transients.
GENERAL LAYOUT
Good PC layout techniques are a must. Ground planes for the analog circuitry must be used and should be tied back to the small pin
grounds 9, 14 and 23. Additional ground, pin 26 is an isolated ground that connects internally directly back to the main DC bus ground pin
27, 28. This can be used as necessary for voltage sensing, etc.
LOW POWER STARTUP
When starting up a system utilizing the MSK4324 for the first time, there are a few things to keep in mind. First, because of the small
size of the module, short circuiting the output phases either to ground or the DC bus will destroy the bridge. The current limiting and control
only works for current actually flowing through the bridge. The current sense resistor has to see the current in order for the electronics to
control it. If possible, for startup use a lower voltage and lower current power supply to test out connections and the low current stability.
With a limited current supply, even if the controller locks up, the dissipation will be limited.
COMPENSATION AND ANTI-WINDUP
By observing the E/A OUT pin which is the error amp output, much can be found out about the health and stability of the system. An
even waveform with some rounded triangle wave should be observed. As current goes up, the DC component of the waveform should
move up or down. At full current (with a regular supply) the waveform should not exceed +8 volts positive peak, or -8 volts negative peak.
Some audible noise will be heard which will be the commutation frequency. If the motor squeals, there is instability and power should be
removed immediately unless power dissipation isn't excessive due to limited supply current. For compensation calculations, refer to the
block diagram for all information to determine the amplifier gain for loop gain calculations.
Because this high voltage torque amplifier contains only high-side bootstrap supplies, it must continuously PWM the bridge to refresh
the high-side supply capacitors. Additionally, this type of amplifier controls the loop through PWM, so it must PWM all of the time in order
to maintain control.
When the bridge commutates the motor through each phasing state, the current path switches windings. The current must be ramped
back up after each transistion. With an integrating compensation scheme, it is very possible for the error amplifier to exceed the PWM
maximum and minimum voltages. When this happens, the loop stops PWM control and the error amplifier will continue to integrate and
ramp up to the voltage rail. This is called integrator windup.
Recovery from integrator windup can take a significant amount of time, long enough for the bootstrap supply capacitors to be depleted
and shut off the gate drive. This must be prevented from happening. By placing zener diode clamps across the error amplifier output to
the inverting input, it will clamp the amplifier from running past the PWM maximum and minimum.
For a free-running clock with no synchronization, the zeners used should be 7.5V. In each direction, the voltage will be 7.5V plus one
diode drop, or 8.2V to 8.5V. If the synchronization pin is being used for clock sync, then that voltage may have to be lower, as the sync
scheme effectively shortens up the PWM ramp to increase frequency and sync clock. A 100 ohm series current limiting resistor is necessary
to prevent the error amplifier from driving too much current back through the feedback when the diodes are conducting.
5
8548-23 Rev. G 1/15
Industrial Control Electronics
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