Tialinx, Inc.

Mohammad Ardehali

A transconductance-capacitance (G-C) filter of arbitrary order is provided that is biased by a bias circuit such that the G-C filter is robust to variations in process corner and temperature as well as input supply noise. The bias circuit includes a biased transistor that has a width-to-length ratio that is a factor X times larger than a corresponding transistor in the G-C filter. The biased transistor couples to ground through a switched capacitor circuit.

Tunable transconductance-capacitance filter with coefficients independent of variations in process corner, temperature, and input supply voltage

A pulse generator is provided that includes: a current source, a source follower whose output controls the gate of a FET and a differential stage whose input voltage consists of inverting square waves and its output voltage consists of extremely narrow pulses widths, for example, of 30 to 40 ps and amplitude of 1.5 Volts.

Narrow pulse generator

In one embodiment, a switching power amplifier is provided that includes: a power switch coupled between a power supply node and ground, wherein the power switch is configured to be cycled on and off responsive to an input signal voltage; and a matching network coupled between a terminal of the power switch and an output node, wherein the matching network includes: a first capacitor coupled between the terminal of the power switch and ground; a second capacitor having a first terminal and an opposing second terminal, the second terminal being coupled to ground, the second capacitor having a greater capacitance than the first capacitor; and a second switch coupled between the first terminal of the second capacitor and the terminal of the power switch, the second switch being configured to be cycled on and off responsive to a switching signal voltage such that the second switch is turned on before the power switch is turned off and such that the second switch is turned off after a current through the power switch is substantially zero responsive to the turning off of the power switch.

High-efficiency switching power amplifiers with low harmonic distortion

In one embodiment, a voltage-controlled oscillator (VCO) is provided that includes: a plurality of differential inverter stages coupled to form a loop, each differential inverter stage having including a switched capacitor circuit configured to control a signal delay through the differential inverter stage responsive to a control circuit, whereby an output frequency for the VCO is inherently compensated against changes in semiconductor process variations and thermal variations.

Self-compensating voltage-controlled oscillator

In one embodiment, a voltage-controlled oscillator is provided having an output signal whose frequency is responsive to a tuning signal and is independent of amplitude of oscillation. The voltage-controlled oscillator includes: a plurality of differential inverter stages coupled to form a loop, each differential inverter stage having a differential pair of transistors configured to steer a tail current from a current source, the current source sourcing the tail current responsive to a feedback signal; and a control circuit configured to generate the feedback signal responsive to a reference signal such that an amplitude of the output signal is independent of the tuning signal and depends on the reference signal, and the frequency of oscillation is decoupled from the amplitude of oscillation.

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Camarillo, CA, United States of America

Mohammad Ardehali