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BC107A (TO18) and BC327B (TO-92) SOT23 equivalent

Huttojb1

Member
Good morning all.
Wonder if anyone could help in advising 2 equivalent transistors to replace a NPN BC107A package type TO-18 and PNP BC327B package type TO-92. I have been using these devices for a while but going more and more surfaces mount and these are probably the last components I need to replace.

I’ll purchase the items usually from RS COMPONENTS in the Uk (https://uk.rs-online.com/web/)

An SOT-23 type would be perfect.
Thank you for your help.
jason.
 

Pommie

Well-Known Member
Most Helpful Member
Most BC series are pretty old and most SOT23's are far superior. What are you using them for?

Mike.
 

Huttojb1

Member
Mike. Thanks for the reply,

Mainly switching reply’s on and off from a PIC controller. High side and low side of the relay coil.
 

Pommie

Well-Known Member
Most Helpful Member
If it's switching then just make sure the base current is 10% of the collector current and all will be good and AG will be happy!

Mike.
 

ChrisP58

Well-Known Member
Most Helpful Member
Personally, I'm a fan of pre-biased transistors for your usage. These are transistors that include base or base/base-emitter resistors integrated into the same package.

Unit cost is comparable to discrete parts. The big savings is that you have fewer parts to place, so smaller total footprint and lower population cost.

They're available with different resistance values and ratios to fit many application.

They come in single or dual configurations, as NPN, PNP (and NPN/PNP in the dual package.) Made by many manufacturers.

DigiKey's list of single pre-biased transistors.

DigiKey's list of pre-biased transistor arrays.
 

Huttojb1

Member
Personally, I'm a fan of pre-biased transistors for your usage. These are transistors that include base or base/base-emitter resistors integrated into the same package.

Unit cost is comparable to discrete parts. The big savings is that you have fewer parts to place, so smaller total footprint and lower population cost.

They're available with different resistance values and ratios to fit many application.

They come in single or dual configurations, as NPN, PNP (and NPN/PNP in the dual package.) Made by many manufacturers.

DigiKey's list of single pre-biased transistors.

DigiKey's list of pre-biased transistor arrays.
Thank you. That’s interesting to know. The journey the PCB have taken are step by step, I originally made on veroboard, then cnc’ed the circuit myself using copper and a cnc3040, I have now developed the PCB using easy eda and now I’m trying to go fully surface mount. Example of one of my boards attached
11A65FCE-01DF-4DA2-901A-901CD834F77D.jpegBE3D1B5B-02F1-4817-9FA6-EE8823BBF12B.jpegAD941FF8-EEAF-4AB6-A503-D5021A935AED.jpegBAA606D2-D01E-43EA-BA94-59888314B16E.jpeg
 

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