Question about current-steering circuit

[shinsj]

Homework Statement

my teacher needs me to design a circuit .. which can control the 5 transistor by the change of the current ... it means that when the different value of current .. the one of the 5 transistor can turn on or turn off .. it is so confused

can someone give some hit of this question

Homework Equations

my teacher told me to find some information about current source and current mirror .. but i don't think it is related to the current-steering circuit

The Attempt at a Solution

 

[phinds]

I think you are going to have be WAY more specific before anyone can help you.