US 4,851,715 A · Schottky-clamped transistor logic buffer circuit

Abstract

A high speed interstage STL buffer (27) is disclosed having a low threshold and high driving capability. A first Schottky-clamped grounded emitter transistor (28) receives input signals through a Schottky steering diode (38) and inverts the input signal. The input signal is applied in parallel through a Schottky steering diode (20) to a second Schottky-clamped grounded emitter transistor (12). The collector (22) of the second transistor (12) provides an output of the buffer (27) for driving load current in one direction with respect to the buffer output. A third transistor (40) connected as an emitter follower has the emitter (42) thereof connected to the buffer output for driving load currents in the other direction. The base (46) of the emitter follower transistor (40) is coupled by a Schottky steering diode (50) to the collector (32) of the first transistor (28). The steering diodes (20, 38, 50) have a forward threshold voltage less than that of the Schottky-barrier diodes used to clamp the base-collector junctions of the first and second transistors (28, 12).

Claims11

Dependent claims

A high speed logic buffer circuit, comprising:

an input for receiving signals thereon for driving the buffer circuit;
an output for driving other electrical apparatus;
a first transistor having a Schottky-clamped base and collector junction and having an emitter, said base being driven by signals on said input, and said collector being connected to a potential for allowing collector and emitter current to flow, with its emitter directly connected to ground;
a second transistor having a Schottky-clamped base and collector junction, and having an emitter connected to ground allowing collector and emitter current flow, the collector of said second transistor being connected to said output for allowing current flow in a first direction with respect to said output, the base of said second transistor receiving said input signals;
and
a third transistor having a base driven by signals on the collector of said first transistor, an emitter connected to said output and a ollector connected to a potential for allowing current to flow in a second direction opposite to said first direction with respect to said output.

3 more elements

Dependencies are inferred from the claim text.

Schottky-clamped transistor logic buffer circuit

Life of this patent

Schottky-clamped transistor logic buffer circuit

Life of this patent

Abstract

Claims11