Abstract: The present invention is directed to a system for correcting a voltage offset in a circuit by amplifying an input voltage to produce an amplified voltage; sampling an offset voltage present in the amplified voltage during a sampling mode; subtracting a value of the offset voltage from the amplified voltage during a correction mode; producing an output voltage; adding a feedback voltage to the input voltage based upon the output voltage; and maintaining the output voltage at substantially the same voltage during the sampling mode and the correction mode.

Abstract: Circuits having switched capacitors that are implemented with T-structures in which one of the three capacitors in the T-structure is implemented with a buffer amplifier configured to receive a control signal (e.g., a control voltage) and to apply a buffered control signal to an active device having a capacitance that is dependent on the control signal level. In one embodiment, the control signal is a control voltage, the active device is a varactor diode, and the circuit is a ladder filter having one or more switched capacitors, each of which is implemented using the T-structure of the present invention. Under the present invention, continuously tunable circuits can be implemented with discrete elements where the circuits can be tuned by changing the control signal in one or more of the switched capacitors, without having to provide a continuously tunable clock.

Abstract: The present invention relates to a radio receiver adapted for use in a time division multiple access (TDMA) system. The radio receiver includes DC compensator circuits configured to decrease the time required to cancel DC offset before received data bursts by DC coupling a radio frequency (RF) demodulator to a baseband channel. The radio receiver may also employ AC capacitive coupling having time modification so as to increase the AC coupled setting time and provide a low pole in a RF-to-Baseband interface.

Abstract: An operational amplifier and method for making same, with predetermined common mode voltage gain, adapted to form an amplifier and a voltage regulator. The predetermined common mode voltage gain allows for substantially reduced differential mode gain and wider operating bandwidth with little distortion, compared to amplifiers and voltage regulators using operational amplifiers of the prior art. Further, examples of operational amplifiers, having the reduced differential mode gain and predetermined common mode gain, are given for implementation in CMOS and bipolar technologies.