Which of following matchs best to a singal NPN transistor with the relationship of 1:N? And which one is the worst?
1. n NPN transistors. In layout, the n transistors can be put together and beside the signal transistor, but cannot put around the singal one.
2. a NPN transistor, with n emitters. Each emitter and the base, the collector has the same area to the corresponding area of the singal transistor.
3. a NPN transistor, the area of the emitter is n times of that of the singal transistor.