UM0723 Datasheet, PDF (23/48 Pages) STMicroelectronics – 1 kW three-phase motor control demonstration board

UM0723
Board description
For six-step configurations it is necessary to set the proper gain by removing the W10
jumper and applying the W11 jumper to the not marked position.
In Table 1 the mentioned setting of gain jumpers, for all possible current reading
configurations, is shown.
Table 1. Current reading configuration
Jumper
Gain configuration
Six-step current reading
FOC current reading
W10
Not present
Present
W11
Not marked position
“-” position
3.3.7
3.3.8
The tachometer and Hall/encoder inputs
Both the tachometer and Hall/encoder inputs have been implemented on the board. In the
case of using a Hall or encoder sensor, the W4 jumper must be connected and the W7
jumper disconnected. The W16 jumper set to dash marked “-” position allows to supply any
connected Hall sensor with +5 VDC supply voltage. Setting the W16 jumper to not marked
position supplies the Hall sensor with the same supply voltage as other hardware
peripherals (+3.3 VDC or +5 VDC depend on the W1 jumper). The U11 Hex Schmitt inverter
is used as the voltage level shifter for the connected Hall sensor.
In the case of using a tachometer, the W4 jumper must be disconnected and the W7 jumper
connected.This feature allows to test and evaluate a wide spectrum of various motors.
Temperature feedback and overtemperature protection
Hardware overtemperature protection is implemented on the STEVAL-IHM023V2
demonstration board. This feature fully protects the switches against damage when
temperature on the junction of the switches overruns a defined value. The temperature is
sensed with an NTC resistor placed on the heatsink. The measured signal is fed through the
J5 motor connector to the MCU control unit and can be read with an A/D converter. The
signal is also fed to comparator U8 where it is compared with a 2.5 V reference voltage
which is built around the U9 precision reference Tl431. The output signal of the comparator
U8 is fed to the SD pin of the L6390D drivers to stop the commutation of the connected
motor. With the value of the NTC resistor used equal to 10 kΩ, and resistor R44 equal to
3.6 kΩ, the shutdown temperature is around 70 °C.
Figure 14. NTC placement on the heatsink
Doc ID 15870 Rev 4
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