X-NUCLEO-DOL10A1 Industrial digital output expansion board based on IPS1050LQ for STM32 Nucleo

The X-NUCLEO-DOL10A1 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 IPS1050LQ single low-side smart power solid state relay, with configurable smart overload protection.

The X-NUCLEO-DOL10A1 expansion board interfaces with the microcontroller on the STM32 Nucleo via STISO620 and Arduino®R3 connectors. The expansion board can be connected to either a NUCLEO-F401RE or a NUCLEO-G431RB development board.

The digital isolators STISO620 (featuring 2.8 kVRMS galvanic isolation) and the isolated dc-dc DC1 (featuring 3 kVDC isolation) protects the logic side from the typical harsh environment on the process side.

The logic side is the application side where the MCU operates and it is supplied by the VISOL rail (3.3 V or 5.0 V, according to setting of SW7). 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-DOL10A1 is stacked on a NUCLEO-F401RE, or on a NUCLEO-G431RB, the VISOL is supplied by the Nucleo board if connected to a PC/Laptop by USB cable. If the X-NUCLEO-DOL10A1 is used standalone, then VISOL can be supplied by the CN6[4] (SW7 = close 1-2) or CN6[5] (SW7 = close 2-3).

The process side is the application side beyond the galvanic isolation barrier. On the process side there are three supply rails: the 5VP (5.0 V) and 10VP (10.0 V) both from DC1, an the 6V rail (derived from VFIELDRP line through LDO40LPURY).

The 5VP and 10VP rails can be enabled by JP4 = close. The 6V rail can be enabled by JP5 = close.

The SW11 defines the supply rail of U1: by default from 6V rail (SW11 = close 2-3), or alternatively from 10VP rail (SW11 = close 1-2).

The SW12 defines the pull-up rail of the open drain diagnostic signals: by default from 6V rail (SW12 = close 2-3), or alternatively from 5VP rail (SW12 = close 1-2).

The VFIELDRP rail (from CN1 connector) is protected both from reverse polarity on CN1 (by the STPS1H100A, provided that J1 remains open) and against surge pulse (by SM15T39CA (U2), provided that J2 is set closed).

The load is connected between the CN1[2] connector and the process side supply rail (typically 24 V) on CN1[1]. The reference rail (ground) of the process side power supply rail must be connected to CN1[3].

The SW13 allows the selection or not of the external TVS that ca be used for the demagnetization of the inductive load and for sustaining the surge pulse on the output stage.

The low side power switch integrated in U1 can be activated/deactivated by the control signals INL: by default, this signal is controlled by CN5[2] through SW1[1-2].

The on board green LED D5 can be enabled by closing J3: this is driven ON/OFF according to the status (active/inactive) of the low side power switch (OUT) integrated in the U1.

The diagnostic signal OVTL (over-temperature) is available on CN9[6] (SW6 = close 1-2) or CN5[4] (SW6 = close 2-3).

Smart overload protection can be configured through the inrush current level setting as follows:

The switches SW1, SW2, SW3, SW4, SW6 offer to the user some flexibility for the remapping of the driving signals INL, IPD1L, IPD2L, IPD3L and OVTL on CN5, CN8 and CN9 (see Schematic diagrams for further details).

It is also possible to evaluate a system composed of a X-NUCLEO-DOL10A1 stacked on other expansion boards.