Applied Micro Circuits Corporation

Globespan Virata Corporation

Globespan, Inc.

Runhua Sun

Thomas Clark Bryan

Zhixiang Jason Liu

A charge-pump and a method are provided for conditioning the phase detector output in a phase-locked loop (PLL). The method comprises: accepting a pair of differential phase detector (PD) output signals (up/upb and dn/dnb); connecting each pair of differential PD outputs to first and second charge-pump differential sections; supplying differential charge-pump outputs (Vout&plus;/Vout&minus;) in response to the pair of differential PD output signals; and, disconnecting the charge-pump differential section outputs from the loop filter inputs when the PD differential outputs (up/dn and upb/dnb) are equal. In some aspects, supplying differential charge-pump outputs (Vout&plus;/Vout&minus;) in response to the pair of differential PD output signals includes sourcing a first current through the first charge-pump differential section and sourcing a second current through the second charge-pump differential section. Then, the method further comprises maintaining the first current equal to the second current.

High-performance low-noise charge-pump for voltage controlled oscillator applications

An impedance element connecting the outputs of two transistors of a wide-bandwidth amplifier forms a zero. The output of transistor is connected to a current source. The wide-bandwidth amplifier has a bandwidth greater than conventional amplifiers utilizing a single current source without an increase in power dissipation.

Wide-bandwidth differential signal amplifier

A two-stage op-amp circuit including a double-cascode telescopic op-amp circuit in the input stage and a fully-differential op-amp circuit in the output stage and having very high open-loop DC gain, very high unity-gain frequency, and relatively very low power consumption is presented. The input stage op-amp circuit and the output stage op-amp circuit are each comprised of a plurality of electrically connected MOSFET's. The input stage op-amp circuit provides very high gain, high input resistance, and large common mode rejection. The output stage op-amp circuit provides gain, low output resistance, and minimal output loss.

Double-cascode two-stage operational amplifier

A differential, two-stage op-amp circuit comprised of a plurality of electrically connected MOSFET's and including a telescopic op-amp circuit integrated with gain-boost amplifier circuits in the input stage and a fully-differential op-amp circuit in the output stage and having very high open-loop DC gain, very high unity-gain frequency, and considerably low power consumption is presented. The gain-boost amplifiers are configured as fully-differential op-amps, one being configured to be electrically connected to PMOS FET circuitry and the other being configured to be electrically connected to NMOS FET circuitry. The input stage op-amp circuit provides high gain, high input resistance, and large common mode rejection. The gain-boost op-amp circuits and the input stage form a local unity-gain feedback, and the outputs of the gain-boost op-amp circuits are adaptively stabilized. The output stage op-amp circuit provides gain, low output resistance, and minimal output loss.

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Tustin, CA, United States of America

Runhua Sun