ATAVRMC300 Atmel, ATAVRMC300 Datasheet - Page 4

• Manufacturer Part Number: ATAVRMC300
• Description: BOARD EVAL LV MOTOR CONTROL PWR
• Manufacturer: Atmel
• Series: AVR®r

Specifications of ATAVRMC300

• Main Purpose: Power Management, Motor Control
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ATmega32M1
• Primary Attributes: 3-Ph BLDC, Brushed DC, Stepper Motor Driver Board, 40V, 6A
• Secondary Attributes: Requires ATAVRMC301, ATAVRMC303, or ATAVRMC310
• Processor To Be Evaluated: ATmega32M1
• Data Bus Width: 8 bit
• Interface Type: RS-232, USB
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4
AVR194
Figure 4. Power Stage
Reading hall sensor values indicates which switch should be closed.
Table 1. Switches commutation for CW rotation
For motors with multiple poles the electrical rotation does not correspond to a mechanical rota-
tion. A four pole BLDC motor uses four electrical rotation cycles to have one mechanical
rotation.
The strength of the magnetic field determines the force and speed of the motor. By varying the
current flow through the coils, the speed and torque of the motor can be adjusted. The most
common way to control the current flow is to control the average current flow through the coils.
PWM (Pulse Width Modulation) is used to adjust the average voltage and thereby the average
current, inducing the speed. For example, the PWM frequency selected is the range from 10kHz
to 200kHz according to the application (commutation losses, audible frequency...).
For a three phase, three coil BLDC motor, the rotating field is described in
Hall Sensors Value (H3 H2 H1)
VDC
101
001
010
100
011
110
+V
0
Q1
Q2
Phase
U-W
V-W
W-U
W-V
U-V
V-U
Q3
Q4
Q5
Q6
Figure
U
V
W
Switches
Q1 ; Q4
Q1 ; Q6
Q3 ; Q6
Q3 ; Q2
Q5 ; Q2
Q5 ; Q4
5.
8138A–AVR–04/08