Analog Devices,inc.

Edward B Hilton

Vincenzo DiTommaso

William Louis Walter

Kenneth J Stern

Thomas Alan Gaiser

Farhad Vazehgoo

Douglas W Babcock

Robert A Duris

A precision SET-RESET logic circuit and operating method separate a latch function from the critical signal path which produces the logic outputs. In a particular implementation the logic circuit includes two differential switch pairs controlled respectively by SET and RESET inputs, with respective enable circuits for the differential pair controlled by the output of the latch circuit. The SET and RESET differential switch pairs respond faster than the latch circuit to a change to the input SET-RESET state. A logic output is initially produced by establishing a first current path through. the differential switches and enable circuits in response to a new logic input, and then latched via a different current path.

Precision set-reset logic circuit and method

A precision SET-RESET logic circuit and operating method separate a latch function from the critical signal path which produces the logic outputs. In a particular implementation the logic circuit includes two differential switch pairs controlled respectively by SET and RESET inputs, with respective enable circuits for the differential pair controlled by the output of the latch circuit. The SET and RESET differential switch pairs respond faster than the latch circuit to a change to the input SET-RESET state. A logic output is initially produced by establishing a first current path through the differential switches and enable circuits in response to a new logic input, and then latched via a different current path.

Precision set-reset logic circuit

Current switches are arranged to reduce signal transit-time variations when they switch current signals that have a wide range of current magnitudes. The transit-time variations are reduced by shifting the range of currents that are carried by switching transistors. In particular, a current range is shifted upward to a higher current range in which the variation of the transistors' transition frequency f,is reduced. In general, the switches include a differential pair of transistors, an offset current source that generates an offset current and a current-steering system that steers the offset current along a current path that includes a switched-on transistor but excludes the output port of that transistor.

Wide dynamic-range current switches and switching methods

Time-delay circuits are realized with first and second capacitors, a differential amplifier, a programmable current source and a differential pair of transistors. The current source directs first and second currents to the first and second capacitors and the differential pair steers a third current of the current source to either selected one of the capacitors to provide charging and discharging currents to the capacitors. The differential amplifier generates a delayed output pulse in response to voltages of the first and second capacitors. The capacitors are preferably formed by the interconnection system of an integrated circuit, i.e., the metallic circuit paths that are typically carried on an integrated-circuit substrate. N+1 of the delay circuits are combined with a phase comparator to form an interpolator that responds to an input data pulse by generating N output data pulses that span a period between the input data pulse and a successive input data pulse.

Delay and interpolation timing structures and methods

A parasitic capacitance cancellation circuit for a direct bonded silicon-on-insulator integrated circuit includes one or more transistors fabricated silicon-on-insulator; a silicon substrate region outside the transistor(s) having a parasitic capacitance to be cancelled; a bootstrap terminal connected to the region outside the transistor(s); and a unity gain buffer responsive to the output of the transistor(s) and having its output connected to the bootstrap terminals for providing a voltage to the region outside the transistor(s) which follows the voltage developed on the parasitic capacitance and nullifies the parasitic capacitance.

Growing community of inventors

Wayland, MA, United States of America

Edward B Hilton