High speed differential output driver with increased voltage swing and predrive common mode adjustment
AssigneeInternational Business Machines Corporation
InventorsEric John Lukes, James David Strom, Dana Marie Woeste
Life of this patent
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Abstract
A high speed differential output driver is provided with increased voltage swing and predrive common mode adjustment. The high speed differential output driver includes a differential input with a voltage amplifier receiving the differential input signal and a common mode adjustment signal and providing an adjustable voltage amplified signal. An emitter follower is coupled to the voltage amplifier. The emitter follower provides a level shifted voltage amplified signal. A driver is coupled to the emitter follower receiving the level shifted voltage amplified signal and providing a driver output signal.
Claims12
A high speed differential output driver comprising:
- a differential input signal;
- a voltage amplifier receiving said differential input signal and a common mode adjustment signal and providing an adjustable voltage amplified signal;
- an emitter follower coupled to said voltage amplifier, said emitter follower providing a level shifted voltage amplified signal;
- a driver coupled to said emitter follower receiving said level shifted voltage amplified signal and providing a driver output signal;
- and
- wherein a duplicate copy of said voltage amplifier, said emitter follower and said driver receives said differential input and is connected with a predetermined load and a pair of series connected resistors connected in parallel with said predetermined load.
A high speed differential output driver comprising:
- a differential input signal;
- a voltage amplifier receiving said differential input signal and a common mode adjustment signal and providing an adjustable voltage amplified signal;
- an emitter follower coupled to said voltage amplifier, said emitter follower providing a level shifted voltage amplified signal;
- and
- a driver coupled to said emitter follower receiving said level shifted voltage amplified signal and providing a driver output signal;
- wherein said driver includes a first series connected P-channel field effect transistor (PFET) and N-channel field effect transistor (NFET) receiving a differential signal gate input A1 and a second series connected P-channel field effect transistor (PFET) and N-channel field effect transistor (NFET) receiving a differential signal gate input A0.
A high speed differential output driver comprising:
- an differential input;
- a voltage amplifier receiving said differential input signal and a common mode adjustment signal and providing an adjustable voltage amplified signal;
- an emitter follower coupled to said voltage amplifier, said emitter follower providing a level shifted voltage amplified signal;
- a driver coupled to said emitter follower receiving said level shifted voltage amplified signal and providing a driver output signal;
- a duplicate copy of said voltage amplifier, said emitter follower and said driver receiving said differential input and connected with a predetermined load and a pair of series connected resistors connected in parallel with said predetermined load providing a voltage signal between said series connected resistors;
- and a transconductance amplifier receiving said voltage signal and a reference voltage and providing an output current proportional to a difference between said voltage input and said reference voltage.
Dependencies are inferred from the claim text.