Digital Equipment Corporation of Canada, Ltd.

Ivan T Chan

Russell W Brown

Circuitry and method for integrating current pulses, the circuitry including an integration amplifier having an integration capacitor located in its feedback loop. The current pulse integrator also includes three current sources and four current switches. A first current switch is located between the first current source and a second current source. A second current switch is located between the output of the integration amplifier and the second current source. A third current switch has one end connected to the first current source and the input to the integration amplifier, and the other end connected to the third current source. A fourth current switch is connected between the output of the integration amplifier and the third current source. Current passes through the integration capacitor in a first direction to charge the integration capacitor during a charge state of operation of the current pulse integrator. Current is prevented from passing through the integration capacitor in the first direction during at least one other state of operation of the current pulse integrator. An output current from the integration amplifier during the charge state of operation is substantially equal to an output current from the integration amplifier during the other state or states of operation.

Current-pulse integrating circuit and phase-locked loop

Circuitry and method for generating electrical currents representative of an exponential function of an input current. The circuit includes an input diode chain and an output diode chain. Each of the diodes in the input diode chain has an input current passing therethrough. The input current is produced by an input current source connected in sources with the diode below the cathode of the diode. A voltage driving circuit drives a voltage drop across the output diode chain that has a predetermined relationship to the voltage drop across the input diode chain. The voltage drop across the output diode chain results in a current through the output diode chain. The number of diodes in the output diode chain is preselected relative to the number of diodes in the input diode chain such that the current through the output diode chain is representative of an exponential function of the input current or currents.

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Kanata, Canada

Ivan T Chan