Z8FMC160100KIT Zilog, Z8FMC160100KIT Datasheet - Page 4

• Manufacturer Part Number: Z8FMC160100KIT
• Description: KIT DEV FOR Z8 ENCORE Z8FMC16100
• Manufacturer: Zilog
• Series: Z8 Encore! MC™r

Specifications of Z8FMC160100KIT

• Main Purpose: Power Management, Motor Control
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: Z8FMC16100
• Primary Attributes: 3-Ph DC Motors
• Secondary Attributes: Graphic User Interface
• Processor To Be Evaluated: Z8FMC16100
• Data Bus Width: 8 bit
• Interface Type: USB
• For Use With: 269-4664 - KIT ACC OPTO-ISO USB SMART CABLE269-4661 - KIT ACC ETHERNET SMART CABLE269-4539 - KIT ACCESSORY USB SMART CABLE
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 269-3639

TM
Sensorless Brushless DC Motor Control with Z8 Encore! MC
Microcontrollers
Figure 1. Three-Phase Motor Control System
The algorithm for Back EMF sensing is based on the implementation of a Phase Locked Loop (PLL). This is
especially advantageous during startup, resulting in a gradual increase in the motor speed as well as nearly
instantaneous reversal of direction of rotation on command, as outlined below.
In the conventional approach, during the startup sequence, power is applied to the windings in order to place
the rotor in a known starting position, followed by commutation and start of Back EMF sensing and control. In
contrast, the PLL-based approach implemented herein makes possible locking to the Back EMF signal from
the very onset of startup phase, without the need for the initial placement of the rotor in a specific position.
Moreover, this approach significantly reduces the erratic movement of the motor during startup or reversal of
direction.
Following the startup phase, during the normal operation phase, torque/current mode control is achieved via
sensing of the voltage generated across a sense resistor in the motor drive circuit. This voltage is routed to the
on-chip integrated ADC, after which data processing by the CPU based on a predefined computational
algorithm results in the regulation of the Pulse Width Modulation (PWM) commutation signal period.
Another key feature of the Z8FMC16100 MCU is the direct coupling of the on-chip integrated comparator to
the PWM module, enabling fast, cycle-by-cycle shutdown during an overcurrent fault event.
In conjunction with the integrated on-chip hardware blocks, the 3-phase BLDC motor control software
developed herein allows for ease of programming to achieve the desired closed-loop control characteristics.
The routines that enable the sensing of the motor’s Back EMF and current are all interrupt driven. It is critical
AN022602-0810
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