STEVAL-IHM015V1 STMicroelectronics, STEVAL-IHM015V1 Datasheet - Page 40

• Manufacturer Part Number: STEVAL-IHM015V1
• Description: BOARD EVAL ST7FMC2S4T6/STS8DNH3L
• Manufacturer: STMicroelectronics
• Type: Motor / Motion Controllers & Driversr

Specifications of STEVAL-IHM015V1

• Main Purpose: Power Management, Motor Control
• Embedded: Yes, MCU, 8-Bit
• Utilized Ic / Part: ST7FMC2S4, STS8DNH3LL
• Primary Attributes: 3-Ph BLAC, BLDC, PMAC or PMDC Motors
• Secondary Attributes: Graphical User Interface
• Input Voltage: 5 V to 48 V
• Product: Power Management Modules
• Silicon Manufacturer: ST Micro
• Core Architecture: ARM
• Core Sub-architecture: ARM7TDMI
• Silicon Core Number: ST7
• Silicon Family Name: ST7MCx
• Kit Contents: Board
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• For Use With/related Products: ST7MC2S4, STS8DNH3LL
• Other names: 497-8213

Motor control operations
7.5.7
7.5.8
7.5.9
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The maximum current allowed by the GUI has been set to 8 A (see
Stopping the motor (LED action)
Push the Start/Stop button to stop the motor. The LEDs toggle from green to red to indicate
an "idle" state.
Configuring the system for BEMF amplification
It is possible to configure the system to enable a BEMF amplification network. This
configuration can be useful in any circumstance where the BEMF signal is very low, such as
low speed for instance. This network can also compensate the free-wheeling diode voltage
drop, which is not negligible in the case of a low bus voltage value. See AN1103 "Improved
B-EMF detection for low-speed and low-voltage applications". Use the settings in
to enable this feature.
Table 16.
Detecting the BEMF during the PWM on time
The direct back-EMF sensing scheme used by default by the STEVAL-IHM015V1
demonstration board, synchronously samples the motor back-EMF during PWM "off" time
without needing to sense or reconstruct the motor’s neutral point in a sensorless BLDC
motor drive system. Since this direct back-EMF sensing scheme requires a minimum PWM
"off" time to sample the back-EMF signal, the duty cycle cannot reach 100%. Furthermore,
in some applications, that is, HVAC using high-inductance motors, the zero crossing
detection is unsymmetrical at high speeds. It has been noted that the long settling time of a
parasitic resonant between the motor inductance and the parasitic capacitance of power
devices causes false zero crossing detections of the back-EMF. In such cases, the back-
EMF detection during PWM "on" time can be used to solve the problem.
More information on this issue can be found in the application notes AN2030, AN1946 and
AN1103. The STEVAL-IHM015V1 demonstration board can be configured to detect the
BEMF during the PWM "on" time.
Sampling of the BEMF can be performed using three different references.
●
●
●
BLDC_3PH_SL
Internal reference (default configuration)
V
Reconstructed neutral point external reference.
Driving mode
Bus/2
external reference
BLDC SL with BEMF amplification jumper settings
J11 between 2-3, J12 between 2-3, J13 between 1-2
J15 between 2-3, J16 between 2-3, J17 between 1-2
J18 between 2-3, J19 between 2-3, J20 between 1-2
J3 Closed, J4 variable (2-3)
Jumper setting
Section
7.4.8).
Table 16
UM0432