Low Noise NPN Rec

[sbest]

Can I get a recommendation on a small signal BJT (in a small form factor like SOT-323) that has a low noise figure? That would work well in a mic preamp. I have played with BC847 and MBT3906. Thanks in Advance

[peranders]

Why so small?

SSM2210 and SSM2220 from Analog Devices are good but comes in a larger package.

[jcx]

um, what type of mic? what impedance, level, location in signal chain?

a ribbon or dynamic is different from a condenser capsule is again different from a buffered electret

[Minion]

I use these in To-92 but might come in other Form factors , BC549, BC550 , They are low noise , come in 3 different gain catagories , are cheap and are used in a Lot of discrete preamps and discrete opamps ....


http://www.fairchildsemi.com/ds/BC/BC550.pdf


Cheers

[peranders]

Thread started wanted small transistors. TO92 is huge

[stinius]

The THAT 300 series?

[peranders]

Those are even bigger. SOT23 or similar was wanted.

[sbest]

Thanks, I using a balanced electret mic and the NPN is used for bias – a traditional capacity multiply circuit. I found a few low noise candidates and it looks like Fairchild specs the NF on their BC850 at 1.4 dB (max 3dB). In turn, this is feed into a balanced gain stage where I’m using a dual OP AMP. So far I’m looking at BB’s OPA2350 and OPA2132. The reason this is so small is that I would like fit all of this into a mic assembly.

[sbest]

Ok,
Just learning how the Post Reply works... Sorry for the repeat message.

Thanks, I using a balanced electret mic and the NPN is used for bias – a traditional capacity multiply circuit. I found a few low noise candidates and it looks like Fairchild specs the NF on their BC850 at 1.4 dB (max 3dB). In turn, this is feed into a balanced gain stage where I’m using a dual OP AMP. So far I’m looking at BB’s OPA2350 and OPA2132. The reason this is so small is that I would like fit all of this into a mic assembly.