Simple electronic switch for common ground loads

[Abdel_Rahman]

I have that model for a circuit used for IGBTs firing ( as in Circuit.1)

I want to energize A then B from micro-controller in a frequency about 50kHZ. with about 10 mA
I want micro-controller pin not to be loaded with more than 1 mA.

firstly I have intended to use "transistor as a switch" but I can not use it with common collector because the ground is common, so I have to use it as common-emmiter. but the problem is the output current is not greater than 3mA even if using 12V for transistor Vcc and higher current gain models (2n2222, bc247...)

Also I can not use optocoupler as circuit frequency is high (about 50kHZ)

I am searching for a solution. just fast electronic switch for common ground loads
Thanks in advance

 

[Alec_t]

I've suggested a circuit over at AAC.