AN1905 ST Microelectronics, Inc., AN1905 Datasheet - Page 5

• Manufacturer Part Number: AN1905
• Description: St7mc Three-phase BLDC Motor Control Software Library
• Manufacturer: ST Microelectronics, Inc.

OVERALL SOFTWARE ARCHITECTURE
ST7MC Library Version 1.0 Characteristics (CPU running at 16 MHz)
- BLDC (trapezoidal 6 step method) modes available:
- 12-bit PWM generation frequencies:
1. Sensorless : Back EMF voltage on the non-energized phase is monitored and used to
2.Voltage : PWM duty cycle is set directly via 12-Bit PWM Generator.
3.Open loop operation.
Current mode, Voltage mode: fixed 390Hz, 625Hz, 961Hz, 1.25Khz, 1.56Khz, 3.13Khz,
6.25Khz, 10Khz, 12.5Khz, 15.4Khz, 18.1Khz, 20Khz, 25Khz, 33.33Khz, 40Khz, 50Khz.
(Voltage mode PWM frequency can be manually adjusted up to 50Khz in the library)
trigger the commutation events
Sensor : Hall effect sensors trigger the commutation events.
Current : Internal current loop and external voltage reference are used conjointly to set
the maximum current in motor windings. PWM duty is automatically set according to cur-
rent feedback loop output.
Closed loop operation : PI regulation, 1 to 255 ms sampling time.
REGULATION
PI
ST7MC THREE-PHASE BLDC MOTOR CONTROL SOFTWARE LIBRARY
WDG
APPLICATION LAYER
PWM outputs
MCO[0..5]
I/Os
PMDC MOTOR DRIVE
MTC
MCIx (Optional hall effect sensors)
MCES
ADC
LIN
SCI
COMMUNICATION
PROTOCOL
SPI
Timer
16-bit
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