SOT-23 breakout PCB
Posted: Wed Apr 28, 2021 5:37 pm
A SOT-23 footprint is used a lot in electronic printed circuit board (PCB) SMD layouts. They are quite small, around 1.5mm x 3mm long - excluding the metal pads. You can buy a huge range of MOSFETs, transistors and even diodes in that format. This board can be used for all of these, including N-MOS and P-MOS, NPN or PNP devices.
There have been times when I have wanted to test or check a SOT-23 based MOSFET on a breadboard, so that leaves me having to cut up a small piece of vero board and carefully solder the MOSFET into place: But it could all be easier if I had a small SOT-23 blank PCB that I could solder the device into place, so I created such a board:
Only two resistors are usually needed, a low value gate resistor and a 10K to 100K ohm pull down resistor for N-MOS, or configured as a pull up for a P-MOS resistor. A transistor might use one or two resistors depending on the configuration being used. With horizontal pin headers for easy breadboard use, it will look something like this: On the back of the PCB, are pads for a gate based LED and a back-EMF protection diode that can be placed across the SOT-23 pads. This is a tiny PCB, so I will get a lot of these onto one PCB panel
There have been times when I have wanted to test or check a SOT-23 based MOSFET on a breadboard, so that leaves me having to cut up a small piece of vero board and carefully solder the MOSFET into place: But it could all be easier if I had a small SOT-23 blank PCB that I could solder the device into place, so I created such a board:
Only two resistors are usually needed, a low value gate resistor and a 10K to 100K ohm pull down resistor for N-MOS, or configured as a pull up for a P-MOS resistor. A transistor might use one or two resistors depending on the configuration being used. With horizontal pin headers for easy breadboard use, it will look something like this: On the back of the PCB, are pads for a gate based LED and a back-EMF protection diode that can be placed across the SOT-23 pads. This is a tiny PCB, so I will get a lot of these onto one PCB panel