Qualcomm Incorporated

Sunghyun Park

Ara Bicakci

Shen Wang

Young Gon Kim

Jin-Su Ko

Tzu-Wang Pan

Xiaoyong Li

Cheol-Woong Lee

Jonghoon Choi

Jinbo Li

An apparatus is disclosed for sharing a filter circuit between transmission and reception modes. In example aspects, the apparatus includes a wireless interface device. The wireless interface device includes a transmit chain, a receive chain, and a filter circuit. The transmit chain includes a first component and a second component. The receive chain includes a third component and a fourth component. The filter circuit includes an amplifier, and the amplifier includes a first stage and a second stage. The first stage includes a transmit portion coupled to the second stage and a receive portion coupled to the second stage. The transmit portion and the second stage are coupled together in series between the first component and the second component of the transmit chain. The receive portion and the second stage are coupled together in series between the third component and the fourth component of the receive chain.

Shared filter for transmission and reception

An output portion of a charge pump receives control signals from a phase frequency detector and in response outputs positive current pulses and negative current pulses to a loop filter. A current control portion of the charge pump controls the output portion such that the magnitudes of the positive and negative current pulses are the same. Within the current control portion there is a 'Charge Pump Output Voltage Replica Node' (CPOVRN). The voltage on this CPOVRN is maintained to be the same as a voltage on the charge pump output node. A capacitor leakage compensation circuit indirectly senses the voltage across a leaking capacitor of the loop filter by sensing the voltage on the CPOVRN. The compensation circuit imposes the sensed voltage across a replica capacitor, mirrors a current leaking through the replica, and supplies the mirrored current in the form of a compensation current to the leaking capacitor.

Capacitor leakage compensation for PLL loop filter capacitor

A current mode power amplifier includes a current steering stage configured to steer a scaled current based on differential voltage inputs, a filtered current mirror connected to the current steering stage to receive the scaled current and produce a filtered output current, and a resonant load configured to receive the output current and generate an output voltage signal for transmission.

Current mode power amplifier providing harmonic distortion suppression

An active analog filter () having a MOS capacitor device () with improved linearity is proposed. In an exemplary embodiment, dc bias voltage sources () alter the capacitance of MOS varactors () connected in anti parallel so that the total capacitance of the MOS capacitor device remains constant or within a range over the voltage range of the filter and the filter linearity is set. In a further exemplary embodiment the output stage () of the operational amplifier circuit () of the active analog filter () is modified so that the dc bias voltage is provided by resistors () connected to a current source () already existing in the filter. Thus the linearity is set and the die area is significantly reduced.

Active analog filter having a MOS capacitor device with improved linearity

A method and apparatus for regulating a supply voltage to an integrated circuit is disclosed. The method and apparatus provides good power supply noise rejection characteristics over a wide bandwidth as well as low dropout voltage. In the disclosed methods and apparatus, native NMOS source followers may be stacked and coupled to a supply rail to supply a regulated voltage to a load. The gates of the native NMOS source followers may be coupled to the outputs of internal regulators. The internal regulators may also contain stacked NMOS source followers. In an embodiment, the internal regulators may be supplied by a high voltage source, while native NMOS source followers may be supplied by a low voltage source. In another embodiment, lo-pass filters may filter the signal from the internal regulators to the NMOS source followers. In yet another embodiment, the gates of the source followers may be coupled to the sources of the transistors with the internal regulators.

Growing community of inventors

Santa Clara, CA, United States of America

Sunghyun Park