Improved Half Current Switch Circuit
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
In a conventional half-current switch emitter-follower (HCSEF) circuit for low and mid-range cost/performance systems, a low voltage power supply is used to minimize power requirements. Unfortunately, the circuit's power and delay tolerances can be unsatisfactory. Since the ratio of bias resistors Rc/Re is approximately 2, the voltage toler ance across one resistor (Re) is accordingly amplified across the other one (Rc), causing relatively large variations in the circuit's signal swing and noise margins.