This board is primarily intended for use as a high side switch, that is switching modules connected to a power source where the voltage of that power source is higher than that of the controlling device (microcontoller etc.). An example may be switching a boost converter powered at 5 volts from a GPIO pin of a 3v3 microcontroller or switching a device in an vehicle electrical system from a 5V Arduino.
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front
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back
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outline
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The board has been designed to be quite versatile. It can be used as a module for a breadboard, prototype board or even as a daughter board on a PCB. It supports a number of use cases such as a standard high side switch, it can add slew for switching modules with large capacitors on its power rails and can handle mosfets where the Vgs is lower than the switched voltage with the addition of a zener diode. It can even be used with either Mosfets or BJT transistors or mixed. Especially in the case of a very low controlling voltage, a BJT is useful because it can switch at about 0.7 volts. It can even be used for a single mosfet/transistor together with any pull up/down resistors etc.
It is uses 0805 and SOT-23 components so is "hand solderable". There are just two pad types. The header pin hole spacing is 0.1" and straight or angled header pins can be fitted from either side. For breadboard use the angled pins allow the board to stand vertically, saving some space. Alternatively, wires can be soldered directly to it. The white silk screen pad on the back can be used for a short reference number etc.
A high side design is not optimal for all situations, however. For example, in the case of a simple relay this is best switched on the low side with a single transistor / mosfet. Modules, however, should in general be switched on the high side to prevent them using alternative ground paths. Some modules have an enable pin for switching so consider using this instead.
Ensure that the choice of components is suitable for the application and voltages in use. For mosfets in particular, ensure Vds and Vgs are in specification and a low Rds(on) for power devices.
It has been designed in Kicad 8 and using KiKit for the panellisation. I tried the standard JLCPCB panellisation option but fell foul of their minimum size for Vscore which incur an "engineering" surcharge so I did the panellisation myself having watched a few videos to choose a suitable tool and see how it is done. You still have to declare if your board is a panel of multiple sub boards and then incur a (smaller) "engineering" surcharge. I've added the Gerbers (JLCPCB design rules but probably OK for others too) in case any one wants to use them and a also a document illustrating some use cases of this board.
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full panel
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Gerbers
gerber_panel.zip (425.5 KB)
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Sample use cases
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Sample_use_cases.pdf (850.7 KB)
