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A common denominator in all of these regional statistics is the ability to dramatically decrease global electric motor energy
demand through the implementation of regulatory, non-regulatory and systems/component improvement methods aimed at
reducing the power needs of the motor driver, motors and loads.
The primary applications of electric motors by sectors include:
• Residential: Refrigerators and air conditioners, fans, pumps, kitchen appliances,
washers and dryers, computers, garden tools and appliances
HVAC/Heat
Refrigerator
Microwave
Computer
Washer/
Dryer
Dishwasher
• Commercial: Heating and air conditioning (HVAC), large computers, escalators and elevators,
hoists and cranes, and industrial grade laundry, cleaning and cooking equipment
Escalator
HVAC/Heat
Computers with Monitors
Servers
Industrial
Laundry
Elevator
Pumps/Boilers
• Transportation: Electric trains, trucks, cars, and motorcycles and in related cooling/
ventilation systems, and fluid pumps and servos
Smoke Stacks
Transmission Line
Electric Cars
Power Generating Station
High Speed Electric Train
• Industrial: Pumps and fans, and air and liquid compression
Air
Compression
Fans
Pumps
Liquid
Compression
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Types of Motors
ELECTRIC
MOTORS
DC
MOTORS
EC-PM
Business
Series
Wound
AC
MOTORS
Brushed
Shunt
Wound
Compund
Wound
Universal
Synchronus
Induction
Permanent
Magnet
Single-Phase
Three-Phase
AC Induction Motors (ACIM) motors are typically
driven off the 60Hz line voltage. Noise and voltage peaks are relatively small. However, there are
drawbacks: the motors can only run electrically at
one speed (speed reduction is usually handled by
gearboxes or some other, usually inefficient, mechanical means) and the inrush of electrical current when
the motor is initially powered is usually 5 to 6 times
the steady-state current. These directly line-fed ACIM
motors average approximately 44% efficiency and
are used in many industrial applications as well as in
home appliances and factories.
Inverter-duty ACIMs became necessary as they began to be driven by VFDs (Variable Frequency Drive). Inverter motors can
tolerate the higher voltage spikes produced by VFDs and can run at very slow speeds without overheating. This performance
comes at a cost, since inverter-duty motors can be much more expensive than general purpose motors.
Brushed DC Motors are typically used in cost-sensitive applications where the control system is relatively simple, such as in
consumer appliances, basic industrial equipment and toys.
Stepper Motors are brushless motors which in commercial applications are primarily used in open-loop position control
systems such as printers, scanners, home/office appliances and scientific or medical equipment. Industrial applications
include high speed pick and place equipment and multi-axis computer numerical control machines. Other uses are in
packaging machinery and fluid control systems.
Brushless DC (BLDC) Motors are used in speed and position-control applications such as in fans, pumps and compressors
where reliability and ruggedness are required. These motors are more expensive than their ACIM-equivalents,
but offer a significantly higher efficiency.
Permanent Magnet Synchronous Motors (PMSM) are used in applications requiring precise control and low torque
ripple, such as robotics, servo systems and electric power steering. These motors are closely related to BLDC motors
in construction.
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Electric Motor Efficiency
Fairchild’s Energy Efficient Motor Strategy Offers
Higher Efficiency and Lower Operating Costs
80+%
65
–> 70%
Single Speed
70
–> 80%
2-Speed
Efficiency
Achieving the necessary reductions in system costs requires a dual
strategy – first the reduction in the cost of the motor itself and second,
improvements in the efficiency of the motor with a corresponding decrease
in energy consumption and cost. Advances in the motor control circuits
have enabled the implementation of two-speed and variable speed motor
designs capable of achieving substantial improvements in efficiency
and cost.
Variable Speed
Operating Cost
Regardless of the type of motor, the control system for most implementations consists of a host/network, isolation, controller,
drivers, power output device, power management and sensing/feedback. All of the building blocks have very specific
requirements and very distinct architectural, circuit and process technology needs.
The Motor Control System
Host/
Network
Power
Management
Isolation
Controller
Drivers
Power Output
Devices
Sensing/
Feedback
Motor
The basic building blocks for an Electric Motor Drive System are:
• AC or DC Power Source Conditioning: Provides filtering, rectification and sometimes
power factor correction between the power source and the heart of the motor control
• Host/Network: Provides a user interface, input and control, often via a standard bus or architecture
• Isolation: Provides protection and, if required, level shifting
• Control: Generates motor control signals based on feedback/position sensors, motor characteristics
and other performance parameters
• Drivers: Generate required signal levels to drive the power output devices
• Power Output Devices: Typically IGBTs and MOSFETs
• Sensing/Feedback: Circuitry that processes and conditions speed, position and torque data from the motor
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Critical Design Factors and Challenges of Motor Control Architectures:
•
•
•
•
•
•
•
Efficiency: As noted earlier, there is a significant amount of potential reduction in overall system power dissipation
through: (1) the use of more efficient building block components (2) the implementation of efficient architectures and
topologies and (3) adherence to best-in-class design practices. The control section can have a significant impact of the
total energy consumption within the EMDS (up to 30%-60%); and therefore, improvements on the control section
based on component selection and architecture optimization will have a significant impact on the overall system
power dissipation.
Reliability: Motors are often found in the “core” system area, hence the need for high reliability.
Often the failure of the motor can lead to a ripple down effect where other components fail as a result.
Noise Reduction: Given the nature of the motor control process and the need for multiple, high-speed switching signals
plus the inherent high inductance in many motor designs, it is essential that the components used and the overall system
design/architecture minimize spurious signals.
Heat Generation: By nature, motors and motor control systems have thermal losses and generate heat. This heat can
have an adverse effect on the operation and reliability of adjacent components.
Saving Space: In many applications, power dissipation is a primary concern, and the use of small packages capable of
efficiently handling the high voltages/currents is essential.
Ease of Design: Selecting the right discrete power components or Smart Power Module (SPM®) is key to decreasing
design time, test time, and ultimately time-to-market. Fairchild’s industry-proven solutions are supported by a suite of
comprehensive design tools and applications knowledge focused on accelerating the design process.
Regulatory Implications: Careful selection of the motor control’s power components can decrease the effort required to
meet regulatory compliance requirements.
Fairchild Product Solutions for Motor Control Applications
Fairchild’s commitment to the Motor Control market is unique in that we provide a complete set of solutions
for many applications.
Fairchild’s Motor Control Portfolio
» Optocouplers
» Interface
» Logic
Host/
Network
Isolation
Power
Management
» DC-DC
» PWM Controller
» PFC + PWM Combo
» ASIC
Controller
Sensing/
Feedback
» Motion SPM
Power Modules
» High Voltage
Gate Drivers
Drivers
» IGBTs
» MOSFETs
Power Output
Devices
Motor
» Amplifiers/Comparators
» Analog Digital Converters
» Switches
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Motion SPM® (Smart Power Modules): are highly integrated solutions designed to operate in ACIM, BLDC and
PMSM motor drive applications. The Motion SPM Family supports low power (20W) and high power (7.5kW) designs.
Our broad family of modules is capable of operating at voltages from 40V to 600V, and some include MOSFETs and
IGBTs. On-board features include built-in circuit protection and output drive that is optimized for low-loss IGBTs. System
reliability is further enhanced by the integrated under-voltage lock-out protection, short-circuit protection and temperature
monitoring. The availability of modular solutions which optimize the performance of many of the critical components
within the motor control system helps designers minimize development time and cost.
V T H (1)
T hermister
(26) V B (U)
(25) V S (U)
(24) VB ( V)
(23) V S (V)
(22) V B (W)
(21) V S (W)
(20) IN(UH)
(19) IN(VH)
(18) IN(WH)
(17) V CC ( H)
P (3)
UVB
UVS
VVB
(15) C OM
(14) IN( UL )
(13) IN(VL )
(12) IN( WL )
(11) V F O
(10) C S C
OUT (UH)
UVS
U(4)
VVS
WVB
WVS
IN(UH)
OUT (VH)
VVS
V (5)
IN(VH)
IN(WH)
VC C
C OM
(16) V CC ( L )
R T H (2)
Other outstanding features of this
class of products include:
• 600V-15A 3-phase IGBT inverter bridge including
control ICs for gate driving and protection
• Easy PCB layout due to built-in bootstrap diode and VS output
• Divided negative DC-link terminals for inverter current
sensing applications
• Single-grounded power supply due to built-in HVIC
• Built-in thermistor for over-temperature monitoring
• Isolation rating of 2500Vrms/min
• Improved thermal performance
• Wide array of packages available allowing for smaller footprint
OUT (WH)
WVS
W(6)
VC C
OUT (UL )
C OM
NU (7)
IN(UL )
IN(VL )
IN(WL )
OUT (VL )
NV (8)
VF O
C (S C )
OUT (WL )
NW (9)
Internal Equivalent Circuit and Input/Output Pins
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Brushless DC (BLDC) Motor or Permanent Magnet Synchronous Motor (PMSM) Controllers: Feature advanced Hall sensor
design. The Hall sensor circuitry manages the PWM commutation via switching of the 3-phase inverter. These topologies
operate in two PWM modes: sine-wave mode and square-wave mode, with highest motor drive efficiency achieved in the
square-wave mode.
Complete protection functions include overvoltage, over-current, over-temperature and
short-circuit for motor protection under stressed
applications and in demanding environments.
•
•
•
•
•
•
Supports sine-wave and square
wave architectures
Built-in clock generator
Direct duty cycle control
Build in error amplifier for torque
loop control
PLL angle detection
Synchronous rectification
Field Trench IGBTs Technology: Results in low conduction and switching losses.
Other outstanding features include:
Transfer Characteristics
•
•
•
•
•
•
•
180
C ommon E mitter
VC E = 20V
C ollec tor C urrent, IC [A]
150
o
T C = 25 C
o
T C = 175 C
120
High operating maximum junction temp of 175°C
Positive temperature coefficient for easy parallel operation
High current capability
Low saturation voltage
Fast switching
Tight parameter distribution
Available in green and RoHS compliant packages
90
60
30
0
2
4
6
8
10
Gate-E m itter Voltage,V GE [V]
12
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Gate Drivers: Monolithic half-bridge gate-drive ICs designed for high-voltage, high-speed applications driving MOSFETs
and IGBTs operating up to +600V. Fairchild’s high-voltage process and common-mode noise canceling technique
provide stable operation of high-side drivers under high-dv/dt noise circumstances. Output drivers typically source and
sink 250mA and 650mA, respectively, which is suitable for 3-phase half-bridge applications in motor drive systems.
•
•
•
•
•
•
•
Floating channel for bootstrap operation
to +600V
250/350mA sourcing current
drive capability
550/650mA sinking current drive capability
Matched propagation delay
Built-in protection
Extended allowable negative
VS swing to -9.8V
Output in phase with input signal
3-Phase BLDC Motor Drive Application
PFC-PWM Combos: Specially designed for applications that consist of boost PFC and PWM. These products
require very few external components to achieve versatile protections and compensation. The PWM can be used
in either current or voltage mode. Compared with earlier generations of this type of product they offer lower
operating current.
Other outstanding features include:
VEA
IEA
FBPFC
IAC
VREF
ISENSE
VRMS
VDD
SS
FBPWM
VREF
VDD
OPFC
•
•
•
•
•
•
•
•
PWM configurable for current mode or feed-forward
voltage-mode operation
Internally synchronized leading-edge PFC and
trailing-edge PWM in one IC
Low operating current
PFC over-voltage and under-voltage protections
Cycle-by-cycle current limiting for PFC/PWM
Power-on sequence control and soft-start
Brownout protection
Improved efficiency at light load
OPWM
RT/CT
GND
RAMP
ILIMIT
VREF
Typical Application, Voltage Mode
Design Support and Resources
Fairchild’s constantly expanding product portfolio, coupled with manufacturing process enhancements, innovative topologies
and our deep systems expertise, allow circuit designers to develop the most advanced solution to their present and future
needs. We offer a broad range of SPM®, IGBTs, Gate Drivers, PFC-PWM combos, MOSFETs, phototransistors and diodes
for every motor control application. Also available are reference designs and evaluation boards that guide designers in the
development of specific motor control design solutions.
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