Analog Devices,inc.

Sukhjinder S Deo

Barrie Gilbert

Moshe Gerstenhaber

John Cowles

Roxann Blanchard

Apparatus and method for an output stage of an amplifier are disclosed. A current source circuit provides current to a transistor connected to the amplifier output node to produce output voltage, and the current source circuit has two current mirror paths, one of which replicates the output voltage at the output node. As the output voltage approaches rail, more current is steered to the current mirror path not replicating the output voltage and provides additional current or voltage necessary to keep the current source circuit operational.

Output stage for near rail operation

A transconductance stage has a common-emitter transconductance stage having common emitter transistors, a common-base transconductance stage having common base transistors, wherein collectors of the common emitter transistors and collectors of the common base transistors are cross-connected to allow in-phase signal combining, an input differential signal applied to the common-emitter transconductance stage and the common-base transconductance stage in parallel, and a selectable gain output, the output selectable between at least one high gain and one low gain, wherein the low gain is lower than the high gain. A switchable transconductance stage has at least one input voltage signal having a frequency in the microwave range, a switchable gain setting, the switchable gain setting having at least two gain settings, and an output current signal having a gain determined by the switchable gain setting.

Digitally controlled variable transductance stage for microwave mixers and amplifiers

A peak-to-average measurement system includes an envelope detector to extract the modulation envelope of an input signal having a modulated carrier. The resulting baseband envelope signal is applied to a peak detector and an averaging circuit. In one embodiment, the averaging circuit includes a translinear core to generate a squared signal in response to the envelope signal and an RMS-average circuit to perform the averaging portion of an RMS function. The translinear core may also generate a replicated version of the envelope signal for the peak detector. The use of a common envelope detector for both the peak detector and averaging circuit may provide improved scaling accuracy.

Peak-to-average measurement with envelope pre-detection

A bias circuit is disclosed for use in a temperature compensation system. The bias circuit provides a current that is proportional to a temperature variation raised to an nth power where |n|&#x3e;1 in accordance with an embodiment. In further embodiments, the bias circuit includes a PTAT current source for providing to a driver-stage amplifier a current that is substantially proportional to absolute temperature, and a CTAT current source for providing a current that is complementary to absolute temperature, wherein the PTAT and CTAT current sources coact to provide a PTATreference current that is proportional to an absolute temperature variation to the nth power wherein |n|&#x3e;1.

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Wilsonville, OR, United States of America

Sukhjinder S Deo