The X-NUCLEO-DO40A1 industrial digital output expansion board for STM32 Nucleo provides a powerful and flexible environment for the evaluation of the driving and diagnostic capabilities of the IPS4140HQ quad high-side smart power solid state relay, in a digital output module connected to ≤ 0.6 A industrial loads.
The X-NUCLEO-DO40A1 expansion board offers two different application sides (logic side and process side) electrically separated by the 2.8 kVRMS galvanic isolation featured by the digital isolators STISO621.
The logic side is the application side where the MCU operates and it is supplied by the VISO_L rail (3.3 V or 5.0 V, according to setting of SW1). The on-board Arduino® UNO R3 connectors enable the connection to either a NUCLEO-F401RE or a NUCLEO-G431RB development board.
When the X-NUCLEO-DO40A1 is stacked on a NUCLEO-F401RE, or on a NUCLEO-G431RB, the VISO_L is supplied by the Nucleo board if connected to a PC/Laptop by USB cable. If the X-NUCLEO-DO40A1 is used standalone, then VISO_L can be supplied by the CN6[4] (SW1 = close 1-2) or CN6[5] (SW1 = close 2-3). By default, the signals on CN5[1, 2] and CN9[7, 8] can be driven high/low to activate/inactivate the loads on the process side connected to CN2[1, 2] and CN3[1, 2]. The thermal diagnostic signals of the four output switches embedded in the IPS4140HQ are reported on CN5[9, 10] and CN8[5, 6]. The switches SW2, SW3, SW4, SW5 offer to the user some flexibility for the remapping of the driving signals IN1, IN2, IN3 and STATUS1 on CN5, CN8 and CN9 (see the schematic for further details).
The process side is the application side on the industrial field (24 V operating rail). On the process side there are two supply rails: the VCC rail (typically connected to the 24 V rail) and the VISO_P (3.3 V) generated by the on board LDO40LPU33 (U8).
The VCC rail is protected both from reverse polarity on CN1 (by the STPS1H100A, provided that J1 remains open) and against surge pulse (by SMC30J30CA (U2), provided that J2 is set closed). The VCC rail supply both the IPS4140HQ and the LDO40LPU33.
The VISO_P rail supplies both the digital isolators and the red diagnostic LEDs D7, D8, D9, D10 reporting the per-over-temperature fault of output channels OUT1, OUT2, OUT3, OUT4, respectively.
Up to four industrial loads can be connected between the CN2[1, 2] and CN3[1, 2] connectors and the process side ground (CN1[2]). The four green LEDs D1, D2 D3, D4 can be used to monitor the status on/off of the respective output switches OUT1, OUT2, OUT3, OUT4. The above four green LEDs can be disabled by opening the J4 positions 1-2, 3-4, 5-6, 7-8.
It is also possible to evaluate a system composed of a X-NUCLEO-DO40A1 stacked on other expansion boards.
