MIL-PRF-38534 CERTIFIED FACILITY
M.S.KENNEDY CORP.
10 AMP, 75V, H-BRIDGE
MOSFET BRUSHED
MOTOR CONTROLLER
4707 Dey Road Liverpool, N.Y. 13088
4250
(315) 701-6751
FEATURES:
75 Volt Motor Supply Voltage
10 Amp Output Switch Capability
100% Duty Cycle High Side Conduction Capable
Shoot-Through/Cross Conduction Protection
"Real" Four Quadrant Torque Control Capability
Good Accuracy Around the Null Torque Point
Contact MSK for MIL-PRF-38535 Qualification Status
DESCRIPTION:
The MSK 4250 is a complete H-bridge MOSFET Brushed Motor Control System in an electrically isolated hermetic
package. The hybrid is capable of 10 amps of output current and 75 volts of DC bus voltage. It has the normal
features for protecting the bridge. Included is all the bridge drive 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 mode for the tightest control and the most bandwidth. Provisions for applying different compensation schemes are included. The MSK 4250 has good thermal conductivity of the MOSFET's due to isolated substrate/
package design that allows direct heat sinking of the hybrid without insulators.
EQUIVALENT SCHEMATIC
TYPICAL APPLICATIONS
Brushed DC Motor Control
Servo Control
Fin Actuator Control
Voice Coil Control
Gimbal Control
AZ-EL Control
1
Rev. G 3/11
ABSOLUTE MAXIMUM RATINGS
V+ High Voltage Supply 9
VIN
Current Command Input
+Vcc
-Vcc
IOUT
Continuous Output Current
IPK
Peak Output Current
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75V
±13.5V
+16V
-18V
10A
20A
θJC Thermal Resistance @ 125°C
TST Storage Temperature Range
TLD Lead Temperature Range
(10 Seconds)
TC Case Operating Temperature
MSK4250
MSK4250H
TJ Junction Temperature
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8
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4.9°C/W
-65°C to +150°C
+300°C
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-40°C to +125°C
-55°C to +125°C
+150°C
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ELECTRICAL SPECIFICATIONS
All Ratings: Tc=+25°C Unless Otherwise Specified
Parameter
Group A
Subgroup
3
MSK 4250
2
4 5
Min.
Typ.
Max.
Min.
Typ.
Max.
@ +15V
1,2,3
-
60
85
-
60
85
mA
@ -15V
1,2,3
-
16
35
-
16
35
mA
4
23.5
25
26.5
22
25
28
KHz
5,6
21.25
25
28.75
-
-
-
KHz
Test Conditions
MSK 4250H
Units
POWER SUPPLY REQUIREMENTS
+Vcc
-Vcc
PWM
Free Running Frequency
CONTROL
7
±10 Amps Output
4,5,6
1.9
2
2.1
1.8
2
2.2
Amp/Volt
±10 Amps Output
4,5,6
0.425
0.5
0.575
0.40
0.5
0.60
V/Amp
4
-
±5.0
±25.0
-
±5.0
±35.0
mAmp
5,6
-
-
±50.0
-
-
-
mAmp
Input Voltage Range 1
-
±11
±12
-
±11
±12
-
Volts
Slew Rate 1
-
6.5
8
-
6.5
8
-
V/μSec
Output Voltage Swing 1
-
±12
±13
-
±12
±13
-
Volts
Gain Bandwidth Product 1
-
-
6.5
-
-
6.5
-
MHz
Large Signal Voltage Gain 1
-
175
275
-
175
275
-
V/mV
Rise Time 1
-
-
100
-
-
100
-
nSec
1
-
-
100
-
-
100
-
nSec
@ 64V, +150°C Junction
-
-
-
750
-
-
750
μAmps
@ 10 Amps
Transconductance
Current Monitor 7
Output Offset
@ 0 Volts Command
ERROR AMP
OUTPUT
Fall Time
Leakage Current 1
Voltage Drop Across Bridge (1 Upper and 1 Lower) 1
Voltage Drop Across Bridge (1 Upper and 1 Lower) 1
Drain-Source On Resistance (Each MOSFET) 6
Diode VSD 1
TRR 1
-
-
-
4.0
-
-
4.0
Volts
@10Amps, +150°C Junction
-
-
-
5.0
-
-
5.0
Volts
@ 10 Amps, 150°C Junction
-
-
-
0.026
-
-
0.026
Ω
@ 10 Amps, Each FET
-
-
-
2.6
-
-
2.6
Volts
IF=10 Amps, di/dt=100A/μS
-
-
280
-
-
280
-
nSec
-
-
2
-
-
2
-
μSec
Dead Time 1
NOTES:
1 Guaranteed by design but not tested. Typical parameters are representative of actual device performance but are for reference
only.
2 Industrial grade devices shall be tested to subgroups 1 and 4 unless otherwise specified.
3 Military grade devices ("H" Suffix) shall be 100% tested to Subgroups 1, 2, 3 and 4.
4 Subgroups 5 and 6 testing available upon request.
5 Subgroup 1, 4 TA = TC = +25°C
2, 5 TA = TC = +125°C
3, 6 TA = TC = -55°C
6 This is to be used for MOSFET thermal calculation only.
7 Measurements do not include offset current at 0V current command.
8 Continuous operation at or above absolute maximum ratings may adversly effect the device performance and/or life cycle.
9 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.
2
Rev. G
3/11
APPLICATION NOTES
MSK 4250 PIN DESCRIPTIONS
AV+, BV+ - are the power connections from the hybrid to
the bus. All pins for the motor voltage supply should be connected together to share the current through the pins in the
hybrid. The external wiring to these pins should be sized
according to the RMS current required by the motor. A high
quality monolithic ceramic capacitor for high frequencies and
enough bulk capacitance for keeping the V+ supply from
drooping should bypass these pins. 1000μF is recommended.
Capacitors should be placed as close to these pins as practical.
SENSE RESISTOR + - is the top of the sense resistor for
sensing the bridge current and closing the loop. The bottom
of the sense resistor is RTN. All the AV- and BV- pins should
be connected to this point.
AV-,BV- - are the power pins for the bottom of the bridge.
These are to be connected to sense resistor +.
DISABLE - is a pin for externally disabling the output bridge.
A TTL logic low will enable the bridge and a TTL high will
disable it. It is internally pulled up by a 100μAmp pull-up.
AØ, BØ - are the connections to the motor phase windings
from the bridge output. The wiring to these pins should be
sized according to the required current by the motor. There
are no short circuit provisions for these outputs. Shorts to
V+ or gound from these pins must be avoided or the bridge
will be destroyed. All pins for each phase should be connected together to share the current through the three pins in
the hybrid.
CURRENT COMMAND (+,-) - are differential inputs for controlling the module in current mode. Scaled at 2 amps 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 ±5 volts for ±10 amps of motor current.
Going beyond 5 volts of command voltage will force the bridge
to conduct more than the desired maximum current. There is
internal current limiting that will ultimately limit the absolute
maximum current being output by the bridge.
RTN - is the power return connection from the module to the
bus. All internal ground returns connect to this point inside
the hybrid. All three pins should be connected together to
share the current. All capacitors from the V+ bus should
connect to this point as close as possible. All external V+
return connections should be made as close to these pins as
possible. Wiring sizing to this pin should be made according
to the required current.
CURRENT MONITOR- is a pin providing a current viewing
signal for external monitoring purposes. This is scaled at ±2
amps of motor current per volt output, up to a maximum of
±5 volts, or ±10 amps. Going beyond the 5 volt maximum
may result in clipping of the waveform peaks. In DISABLE
mode, the CURRENT MONITOR output may rail positive or
negative, depending on internal bias currents. When re-enabled, this output will resume expected operation.
IN
GND - is the return point for the low powered circuitry inside
the hybrid. All GND pins should be tied together. All capacitors for bypassing the + and -15V supplies should be tied at
this point, as close to the pins as possible. Any ground plane
connections for low powered and analog citcuitry outside the
hybrid should be tied to this point.
E/A OUT - is the current loop error amplifier output. It is
brought out for allowing various loop compensation circuits
to be connected between this and E/A-.
+15VIN - is the input for applying +15 volts to run the low
power section of the hybrid. Both pins should be used together for optimum operation. These pins should be bypassed
with a 10μF capacitor and a 0.1μF capacitor as close to these
pins as possible.
E/A- - is the current loop error amplifier inverting input. It is
brought out for allowing various loop compensation circuits
to be connected between this and E/A OUT.
-15VIN - is the input for applying -15 volts to run the low
power section of the hybrid. Both pins should be used together for optimum operation. These pins should be bypassed
with a 10μF capacitor and a 0.1μF capacitor as close to these
pins as possible.
3
Rev. G
3/11
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 30nH 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.
±15VIN FILTER CAPACITORS
It is recommended that about 10 μF of capacitance (tantalum electrolytic) for bypassing the + and -15V inputs 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 important. Ground planes for the analog circuitry must be used and should be tied back to
the small signal grounds, pin 17, 18, 23, 24, 33 and 34. The high power grounds (RTN) pins 1,2 and 3 get tied back to the
small signal ground internally. DO NOT connect these grounds externally. A ground loop will result.
LOW POWER STARTUP
When starting up a system utilizing the MSK 4250 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. 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 +4 volts positive peak, or -4 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. For the power up sequence, ±15 volts should be
powered at the same time or before the V+ voltage is applied.
4
Rev. G
3/11
MSK4250 TEST CIRCUIT
5
Rev. G
3/11
MECHANICAL SPECIFICATIONS
WEIGHT= 44 GRAMS TYPICAL
NOTE: ALL DIMENSIONS ARE ±0.010 INCHES UNLESS OTHERWISE LABELED.
ESD Triangle indicates Pin 1.
ORDERING INFORMATION
Part
Number
MSK4250
MSK4250H
Screening Level
Industrial
Mil-PRF-38534 Class H
M.S. Kennedy Corp.
4707 Dey Road, Liverpool, New York 13088
Phone (315) 701-6751
FAX (315) 701-6752
www.mskennedy.com
The information contained herein is believed to be accurate at the time of printing. MSK reserves the right to make
changes to its products or specifications without notice, however, and assumes no liability for the use of its products.
Please visit our website for the most recent revision of this datasheet.
Contact MSK for MIL-PRF-38534 qualification status.
6
Rev. G
3/11