Motor Controller delivers sensorless commutation.
July 28, 2006 -
Supplied in SSOP-24 package, Toshiba TB6575FNG provides PWM current control for 3-phase full-wave brushless dc motors. Rotation speed is controlled through variable PWM duty cycle, which is controlled by analog input voltage of 4.5-5.5 V. Capable of forward/reverse rotation, product offers overlap commutation, dc excitation mode, and output polarity switching. DC excitation time and forced commutation time are selectable for start-up operation.
(Archive News Story - Products mentioned in this Archive News Story may or may not be available from the manufacturer.)
Original Press release
Marktech Optoelectronics
3 Northway Lane North
Latham, NY, 12110
USA
Marktech Introduces Toshiba's Newest PWM Sensorless Controller for 3-Phase Full-Wave BLDC Motors
Latham, New York: Marktech introduces the Toshiba TB6575FNG PWM sensorless controller for 3-phase full wave Brushless DC motors. A brushless DC (BLDC) motor is a synchronous motor, which means the rotor position has to be known to generate the appropriate field. BLDC motors are popular because of their durability, linear control characteristics, efficiency and torque-to-volume ratio. Normally sensors (usually Hall-effect devices) are used to determine the rotor position. These sensors are a disadvantage because they add to the system cost, are a source of failure, require extra wires, and are sensitive to EMI. The TB6575FNG provides sensorless commutation and PWM current control for 3-phase full-wave BLDC motors. Rotation speed is controlled through a variable PWM duty cycle controlled by an analog input voltage. On receiving an analog voltage command input, the rotor is aligned to a known position in DC excitation mode. The rotation is started in forced commutation mode by applying a PWM signal to the motor. As the rotor moves, back-EMF is measured and applied to the position signal input pin. Subsequently the device switches from forced commutation to natural commutation (based on the back-EMF sensing) to drive the BLDC motor in sensorless mode.
Features
· Over-current protection
· Forward/reverse rotation
· Overlap commutation
· 20mA current sink capability on PWM output pins
· Lead angle control (7.5° and 15°)
· Rotation speed sensing signal
· DC excitation mode to improve startup characteristic
· DC excitation time and forced commutation time for start-up operation can be changed
· Forced commutation frequency can be selected (fXT/(6 × 216), fXT/(6 × 217), fXT/(6 × 218))
· Output polarity switching (P-channel + N-channel, N-channel + N-channel)
· Supply voltage: 4.5-5.5 V
· Package: SSOP-24
Pricing and Availability
Quantity pricing for the TB6575FNG is $1.40 in 5K lots with free samples currently available. For more information on these or any of our other LED or LED Driver products contact Marktech Optoelectronics at 3 Northway Lane North, Latham, NY 12110, Phone: (800) 984-5337, FAX: (518) 785-4725, email: info@marktechopto.com. Website: www.marktechopto.com.
Marktech Optoelectronics: Marktech has been an industry leader in the application and design of LEDs for over 20 years. Toshiba America Electronic Components, Inc. has chosen Marktech to handle all North American technical sales and marketing for their Tosbright® LEDs and Toshiba Constant Current LED Drivers. In addition to their Toshiba line Marktech also offers a wide range of standard Discrete, Surface Mount, and Dot Matrix Displays along with a complete line of Photo Sensors.
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