UM1036 datasheet(21/47 Pages) STMICROELECTRONICS

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UM1036

Board description

voltage. The output signal of the comparator is fed into the IPM to stop the commutation of

the connected motor as well as into the MCU control unit through the J2 connector. With the

value of the used resistor networks and applied NTC resistor, the shutdown temperature of

the heatsink is somewhere between 85 °C and 90 °C.

2.3.9

Active heatsink cooling

For better thermal transfer of heat from the heatsink, active fan cooling is implemented on

the board. The aluminum profile used is type 8424 from PADA Engineering. The

temperature is sensed with the NTC resistor and compared with a reference voltage in

comparator U9B. The fan is switched on automatically when temperature of the heatsink

reaches approximately 40 °C and is switched off when temperature of the heatsink falls to

35 °C. The thermal resistance of the heatsink, when the fan is not activated, is visible in

Figure 13, the thermal resistance with active fan cooling is visible in Figure 14.

Figure 13. Thermal resistance of the heatsink

UM1036 数据表(PDF) 21 Page - STMicroelectronics