observing that RE or RS can be increased to raise the output resistance. Unfortunately,
however, the voltage drop across the degeneration resistor also increases proportionally,
consuming voltage headroom and ultimately limiting the voltage swings provided by the
circuit using such a current source. For example, if RE sustains 300 mV and Q 1 requires
a minimum collector-emitter voltage of 500 mV, then the degenerated current source
“consumes” a headroom of 800 mV.