SOT-23 breakout PCB

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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:

MOSFET-vero.jpg (33.21 KiB) Viewed 7028 times

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:

SOT-23-PCB-front.jpg (9.95 KiB) Viewed 7028 times

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:

SOT-23-PCB-front.1.jpg (22.83 KiB) Viewed 7028 times

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

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The SOT-23 Breakout PCB arrived the other day. I soldered up two AO3401 and two AO3400 SOT-23 MOSFETs onto some of the breakout PCB's. One thing I didn't take into account, is that I didn't leave enough 'white space' to carefully write the name of the MOSFET onto the PCB.

SOT-23-Breakout_Sml.jpg (48.5 KiB) Viewed 6988 times

These will work really well on a breadboard. The PCB is 1.6mm thick, at this magnification it looks so thick.

[TimH]

Nice - awesome little board, that ruler you gave me really helps put that photo in perspective

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This PCB has been superseded by a PCB that incorporates a DFN1006 and SOT-23 footprint breakout: viewtopic.php?f=9&t=2461#p3784 AND more importantly - space to write the name of MOSFET that's been soldered into place!