Marvellworld Trade Ltd.

Stmicroelectronics Gmbh

Marvell International Limited

Stmicroelectronics S.r.l.

Stmicroelectrontronics, Inc.

Alessandro Venca

Baris Posat

Brian Taylor Brunn

Rinaldo Castello

Roberto Alini

Nicola Ghittori

Alessandro Bosi

Claudio Nani

Kemal Ozanoglu

Sehat Sutardja

Gregory Takeo Uehara

Fernando De Bernardinis

Chao Yang

Ruoxin Jiang

Marc Leroux

Enrico Sacchi

Luca Romano

Stefano Dal Toso

Antonio Milani

Valerio Pisati

Francesco Rezzi

Daniele Ottini

Antonio Liscidini

Luca Fanori

Marco Cazzaniga

Marck Leroux

A hybrid digital-to-analog converter including a charge-sharing digital-to-analog converter and a charge redistribution digital-to-analog converter is provided. The charge-sharing digital-to-analog converter is configured to receive a digital input signal having multiple bits. The bits include a most-significant-bit and a least-significant-bit. The charge-sharing digital-to-analog converter is configured to convert the most-significant-bit to provide a first portion of an analog signal and selectively share charges of first capacitors during a successive approximation of the most-significant-bit. The charge redistribution digital-to-analog converter is configured to convert the least-significant-bit to provide a second portion of the analog signal. The charge redistribution digital-to-analog converter performs charge redistribution by selectively connecting second capacitors to receive reference voltages during a successive approximation of the least-significant-bit.

Charge-sharing and charge-redistribution DAC and method for successive approximation analog-to-digital converters

An A/D converter including first and second A/D converters and a recombination module. The first A/D converter receives an analog input signal, converts the analog input signal to a first digital signal, and includes a successive approximation module, which performs a successive approximation to generate the first digital signal. The second A/D converter converts an analog output of the first A/D converter to a second digital signal. The analog output of the first A/D converter is generated based on the analog input signal. The second A/D converter is a fine conversion A/D converter relative to the first A/D converter. The second A/D converter performs the delta-sigma conversion process and includes a decimation filter that suppresses noise which reduces amplification and power consumption requirements of the first A/D converter and performs a delta-sigma decimation process to generate the second digital signal based on the analog output of the first A/D converter.

Successive approximation sigma delta analog-to-digital converters

An A/D converter including a sample and hold circuit, first and second A/D converters and a combination circuit. The sample and hold circuit samples an analog input signal to generate bits. The first A/D converter generate a first digital signal based on the analog input signal and includes charge-sharing and charge-redistribution D/A converters that convert respectively a most-significant-bit and a first least significant bit. The first digital signal is generated based on outputs of the charge-sharing and charge redistribution D/A converters. The second A/D converter generates a second digital signal based on an output of the first A/D converter and includes a delta sigma D/A converter, which converts a second least significant bit. The second digital signal is generated based on an output of the delta sigma D/A converter. The second A/D converter is a fine conversion A/D converter relative to the first A/D converter.

Analog-to-digital converters for successive approximation incorporating delta sigma analog-to-digital converters and hybrid digital-to-analog with charge-sharing and charge redistribution

A hybrid D/A converter is provided including first and second D/A converters. The first D/A converter receives a digital signal having an input voltage and converts a first most-significant-bit of the digital signal to be converted to an analog signal. The first D/A converter includes first capacitors, which are charged by the input voltage and reference voltages during a sampling phase of the digital signal. Charges of the first capacitors are shared during successive approximations of first bits of the digital input signal received by the hybrid D/A converter. The second D/A converter converts a first least-significant-bit of the digital input signal. The second D/A converter includes second capacitors, which are charged based on a common mode voltage during the sampling phase. The second D/A converter performs charge redistribution by connecting the second capacitors to receive the reference voltages during successive approximations of second bits of the digital signal.

Hybrid charge-sharing charge-redistribution DAC for successive approximation analog-to-digital converters

In one embodiment, an apparatus includes an upconversion unit configured to upconvert a baseband signal to a radio frequency (RF) signal. A plurality of baluns for a plurality of wireless bands are provided. Multiplexing circuitry is coupled to the plurality of baluns where the upconversion unit is coupled to each balun through the multiplexing circuitry. The multiplexing circuitry is configured to multiplex the radio frequency signal from the upconversion unit to one of the plurality of baluns based on a wireless band being used.

Transmit architecture for wireless multi-mode applications

In accordance with an embodiment of the disclosure, circuits and methods are provided for using a reconfigurable voltage controlled oscillator to support multi-mode applications. A voltage control oscillator circuit comprises a resonant circuit, a first oscillator circuitry coupled to the resonant circuit, and a second oscillator circuitry coupled to the resonant circuit. The voltage control oscillator circuit further comprises switching circuitry configured to select, based on an operating metric, one of the first oscillator circuitry and the second oscillator circuitry for providing an output voltage.

Reconfigurable voltage controlled oscillator for supporting multi-mode applications

In one embodiment, an apparatus includes a jitter generator configured to receive a reference clock; add jitter to the reference clock; and output the reference clock with the included jitter to a phase lock loop (PLL). The PLL is used to generate a local oscillator (LO) signal for a transceiver. A jitter controller outputs a signal to the jitter generator to control a characteristic of the jitter added to the reference clock. The reference clock with the added jitter is used to reduce a fractional spur caused by a radio frequency (RF) attacker coupling into the PLL.

Fractional spur reduction using controlled clock jitter

In one embodiment, a voltage controlled oscillator (VCO) is provided. The VCO includes a tank circuit. Also, the VCO includes a first pair of transistors. The drains of the first pair of transistors are coupled to the tank circuit and the gates of the first pair of transistors are cross-coupled with the drains of the first pair of transistors. The first pair of transistors each have a first threshold voltage. The VCO further includes a second pair of transistors. The drains of the second pair of transistors are respectively coupled to the sources of the first pair of transistors and the gates of the second pair of transistors are respectively coupled to the gates of the first pair of transistors, The second pair of transistors each have a second threshold voltage higher than the first threshold voltage.

High efficiency harmonic voltage controlled oscillator (VCO)

The present invention provides compensation for circuits. In one embodiment, a compensation circuit has a first terminal coupled to an output terminal of the circuit and a second terminal coupled to feed back the output voltage to an internal node. A damping circuit may also be coupled to the output terminal. The damping circuit adds a pole and a zero to the transfer function of the circuit. In one embodiment, the damping circuit modifies the effect of the output impedance of a load on the transfer function to increase the phase margin of the circuit such that the circuit remains stable over an increased range of output capacitor values.

Cascode compensation circuit and method for amplifier stability

An amplifying circuit and method are disclosed for amplifying electrical signals, such as electrical signals generated by the read head of a disk drive. The circuit includes a pair of cross-coupled differential amplifier circuits. Each differential amplifier circuit is asymmetric, including two input transistors of different transistor types. For instance, a first of the two input transistors of each differential amplifier circuit may be a bipolar transistor and a second of the two input transistors may be a field effect transistor. By utilizing asymmetric differential amplifier circuits, a relatively wider operating frequency range is obtained.

Preamplifier circuit and method for a disk drive device

A write driver for driving a write current through a write head connected to the write head by an interconnect or flexible transmission line. The write driver includes a circuit matching an output impedance of the write driver to the odd characteristic impedance of the interconnect and includes a current source generating a current output to the write head. The write driver provides a current amplification effect as the output current is half the write current driven through the write coil. The impedance matching circuit includes an output resistor with a resistance equal to the odd characteristic impedance of the interconnect. The write driver includes a voltage source that operates to maintain a voltage drop of zero on the output resistor during the initial period of twice the transmission delay of the interconnect.

Write driver with power optimization and interconnect impedance matching

A write driver driving a write current through a head connected to the write head by an interconnect. The write driver includes a circuit matching output resistance to the odd characteristic impedance of the interconnect and a voltage boosting circuit. The voltage boosting circuit in connected between a high voltage reference or supply voltage and a low voltage reference, and includes a pair of current sources, such as MOS transistors, connected to the input node of a single capacitor. During the overshoot duration, the current sources selectively operate at saturation to generate a pulsed current with an amplitude of half the load current. The recharge of the capacitor is done with the load current.

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Tortona, Italy

Alessandro Venca