Murata Manufacturing Co., Ltd.

National Semiconductor Corporation

Texas Instruments Corporation

Eta Wireless, Inc.

Ivan Duzevik

David J Perreault

Yevgeniy A Tkachenko

John R Hoversten

James R Garrett

Sri Harsh Pakala

Brendan Metzner

Jitendra Mohan

Arlo Jame Aude

Kenneth Patrick Snowdon

Steven M Macaluso

Khaldoon S Abugharbieh

James J McDonald, Ii

James J Ii Mcdonald

Described are circuits and techniques to increase the efficiency of radio-frequency (rf) amplifiers including rf power amplifiers (PAs) through 'supply modulation' (also referred to as “drain modulation” or “collector modulation”), in which supply voltages provided to rf amplifiers is adjusted dynamically (“modulated”) over time depending upon the rf signal being synthesized. For the largest efficiency improvements, a supply voltage can be adjusted among discrete voltage levels or continuously on a short time scale. The supply voltages (or voltage levels) provided to an rf amplifier may also be adapted to accommodate longer-term changes in desired rf envelope such as associated with adapting transmitter output strength to minimize errors in data transfer, for rf “traffic” variations.

RF power amplifier system having a multi-output supply generator and low-frequency turn off switch

RF power amplifier system with multiple supply modulators

Multi-output supply generator for RF power amplifiers with differential capacitive energy transfer

Described are concepts, circuits, systems and techniques directed toward N-phase control techniques useful in the design and control of supply generators configured for use in a wide variety of power management applications including, but not limited to mobile applications.

Supply generator and associated control methods

Described are circuits and techniques to increase the efficiency of radio-frequency (rf) amplifiers including rf power amplifiers (PAs) through 'supply modulation' (also referred to as 'drain modulation' or &#x201c;collector modulation&#x201d;), in which supply voltages provided to rf amplifiers is adjusted dynamically (&#x201c;modulated&#x201d;) overtime depending upon the rf signal being synthesized. For the largest efficiency improvements, a supply voltage can be adjusted among discrete voltage levels or continuously on a short time scale. The supply voltages (or voltage levels) provided to an rf amplifier may also be adapted to accommodate longer-term changes in desired rf envelope such as associated with adapting transmitter output strength to minimize errors in data transfer, for rf &#x201c;traffic&#x201d; variations.

A voltage/current regulator supplying controlled current with PVT headroom adjustment. In an example application, an LED backlight driver controls ILED string current, and controls a voltage regulator supplying VOUT string voltage with sufficient headroom voltage VHDRM to supply the ILED string current. The LED driver controls ILED string current with an MLED current control transistor, including gate drive referenced to a reference voltage VREF. VOUT/VHDRM are adjusted for PVT operating conditions by generating a replica/reference current ILED/RATIO (proportional to ILED string current) with a replica current control transistor MLED/RATIO based on VREF. ILED/RATIO is mirrored to a second replica MLED/RATIO transistor that saturates at a PVT_REF reference voltage corresponding to a minimum voltage that can supply the required ILED current (as represented by the ILED/RATIO replica/reference current), accounting for PVT operating conditions.

Voltage/current regulator supplying controlled current with PVT adjusted headroom

A low voltage differential signal (LVDS) driver circuit with reduced power consumption. A pre-driver stage, implemented as a differential current mode amplifier, is driven by the differential input signal and provides a corresponding differential drive signal, which drives the output stage, implemented as a differential voltage mode amplifier, which, in turn, provides the differential output signal for the load. Total current consumption equals the load current, which is provided by the output stage, plus a much smaller current used by the pre-driver stage.

Low voltage differential signal driver with reduced power consumption

A low voltage differential signal (LVDS) transmitter with output power control. Internal sensing circuitry monitors output current flow through the termination impedance. When a proper termination impedance is not connected to the output, the resulting improper output current flow (e.g., zero output current when no termination impedance is connected) is detected by the sensing circuitry, which causes the supply current to the output driver circuitry to be reduced. Additionally, further in response to such detection of improper output current flow, the sensing circuitry can cause the output voltage to be limited, e.g., clamped, at a predetermined maximum magnitude.

Low voltage differential signal (LVDS) transmitter with output power control

An apparatus, device, and method for loss of signal detection in a receiver are provided. A reference circuit is operable to rectify a reference signal. An input circuit is operable to rectify an input signal. A comparator is operable to compare outputs of the reference circuit and the input circuit and to generate an output signal based on the comparison. The output signal indicates whether the input signal falls within threshold limits defined by the reference signal. A second reference circuit and a second input circuit could also be used, and the reference circuits and input circuits can be selectively enabled and disabled based on which of multiple differential pairs is enabled in a receiver receiving the input signal. The differential pairs can be used in the receiver to generate an output signal based on the input signal.

Apparatus and method for loss of signal detection in a receiver

An apparatus, device, and method for high-speed serial communications are provided. An input circuit is operable to receive an input signal, where the input circuit includes transistors forming (i) a first differential pair associated with a first current source and (ii) a second differential pair associated with a second current source. An output circuit is coupled to the input circuit and is operable to generate an output signal based on the input signal. A sensing circuit is operable to estimate a voltage associated with one of the current sources. A comparator is operable to compare the estimated voltage and a reference voltage and to selectively enable one of the differential pairs and disable another of the differential pairs based on the comparison. The differential pairs could be enabled and disabled using a first switch associated with the first differential pair and a second switch associated with the second differential pair.

Apparatus and method for high-speed serial communications

A differential driver circuit is configured to automatically adjust its source resistance to be substantially similar to a termination resistance. The differential driver circuit includes a variable resistance circuit on each leg of the differential driver circuit. A replica of one leg of the differential driver circuit is configured for adjusting the variable resistance circuits so that the differential driver circuit's source resistance appears to a load as substantially similar to the termination resistance.

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Portland, ME, United States of America

Ivan Duzevik