SMD version of MPSA18

[garfo]

I have been looking for an SMD package for the MPSA18 and I cannot find anything. Has anyone had any luck with finding this as an smd package?

[jwin615]

Could use mmbt22222

[garfo]

that transistor does not have the same characteristics that I need to replace the MPSA18. I need the higher voltage handling capability, Lower noise figures and also higher gain specs. This is for a Push-pull gain stage to reduce Harmonic distortion.

[mauman]

I did a search at Mouser for SMD BJT that meet or exceed all the relevant properties of the MPSA18, and they have 47 choices.  Here is the link to search results.  The noise factor and beta are not searchable properties, so you'll have to sort those qualities for yourself, but this should give you a head start.  Once you identify the part number you need, Mouser has a presence in Portugal, pt.mouser.com.   
 
https://www.mouser.com/c/semiconductors/discrete-semiconductors/transistors/bipolar-transistors-bjt/?collector-%20base%20voltage%20vcbo=45%20V~~-&collector-%20emitter%20voltage%20vceo%20max=45%20V~~-&collector-emitter%20saturation%20voltage=200%20mV~~-&configuration=Single&emitter-%20base%20voltage%20vebo=6.5%20V~~-&gain%20bandwidth%20product%20ft=160%20MHz~~-&maximum%20dc%20collector%20current=200%20mA~~-&mounting%20style=SMD%2FSMT&pd%20-%20power%20dissipation=625%20mW~~-&product%20type=BJTs%20-%20Bipolar%20Transistors&transistor%20polarity=NPN&rp=semiconductors%2Fdiscrete-semiconductors%2Ftransistors%2Fbipolar-transistors-bjt%7C~Maximum%20DC%20Collector%20Current%7C~Collector-%20Emitter%20Voltage%20VCEO%20Max%7C~Collector-%20Base%20Voltage%20VCBO%7C~Emitter-%20Base%20Voltage%20VEBO%7C~Collector-Emitter%20Saturation%20Voltage%7C~Pd%20-%20Power%20Dissipation%7C~Gain%20Bandwidth%20Product%20fT

[jwin615]

Don't you need a matched PNP NPN pair for(optimal) push pull? May look at transistor arrays if that's the case.
I assumed this was for a pedal so didn't take voltage into account...

I'll add, check out the Alfa offerings

[garfo]

Thank you. I will have a look into this.

I did a search at Mouser for SMD BJT that meet or exceed all the relevant properties of the MPSA18, and they have 47 choices.  Here is the link to search results.  The noise factor and beta are not searchable properties, so you'll have to sort those qualities for yourself, but this should give you a head start.  Once you identify the part number you need, Mouser has a presence in Portugal, pt.mouser.com.   
 
https://www.mouser.com/c/semiconductors/discrete-semiconductors/transistors/bipolar-transistors-bjt/?collector-%20base%20voltage%20vcbo=45%20V~~-&collector-%20emitter%20voltage%20vceo%20max=45%20V~~-&collector-emitter%20saturation%20voltage=200%20mV~~-&configuration=Single&emitter-%20base%20voltage%20vebo=6.5%20V~~-&gain%20bandwidth%20product%20ft=160%20MHz~~-&maximum%20dc%20collector%20current=200%20mA~~-&mounting%20style=SMD%2FSMT&pd%20-%20power%20dissipation=625%20mW~~-&product%20type=BJTs%20-%20Bipolar%20Transistors&transistor%20polarity=NPN&rp=semiconductors%2Fdiscrete-semiconductors%2Ftransistors%2Fbipolar-transistors-bjt%7C~Maximum%20DC%20Collector%20Current%7C~Collector-%20Emitter%20Voltage%20VCEO%20Max%7C~Collector-%20Base%20Voltage%20VCBO%7C~Emitter-%20Base%20Voltage%20VEBO%7C~Collector-Emitter%20Saturation%20Voltage%7C~Pd%20-%20Power%20Dissipation%7C~Gain%20Bandwidth%20Product%20fT

[garfo]

Don't you need a matched PNP NPN pair for(optimal) push pull? May look at transistor arrays if that's the case.
I assumed this was for a pedal so didn't take voltage into account...

I'll add, check out the Alfa offerings

For this particular circuit, not really.