about Bipolar circuit

[tia_design]

One thing bothers me for a long time. I know that circuit deisgn based on CMOS process, we choose biasing current or voltage, the length and width of the MOSFET for the target performance.
But for BJT process, what kinds of parameters are chosen for consideration?

 

[isaacnewton]

One thing bothers me for a long time. I know that circuit deisgn based on CMOS process, we choose biasing current or voltage, the length and width of the MOSFET for the target performance.
But for BJT process, what kinds of parameters are chosen for consideration?

For CMOS, you can change W/L ratio, for BJT, you can only change the the emitter area.