Freescale Semiconductor,inc.

Motorola Corporation

Nxp Usa, Inc.

Freescale Semiconductors Inc.

David Gareth Morgan

Vishal P Trivedi

Jay Paul John

Pamela J Welch

Wen Ling M Huang

James Albert Kirchgessner

Hernan A Rueda

Kuntal Joardar

Kun-Hin To

Ik-Sung Lim

Hernan A Reuda

A technique for tuning a ladder-shaped inductor that achieves a finer tuning resolution by severing one or more shorts, skipping the severing of one or more shorts, and severing one or more subsequent shorts within the ladder-shaped inductor. This technique can be applied to a voltage-controlled oscillator using a differential or single-ended ladder-shaped inductor as part of the resonant circuit. Within an oscillator, such a technique provides for a more precise modulation of the effective inductance of the ladder-shaped inductor, which enables an improved tuning resolution of the operating frequency of the oscillator.

Tunable inductors

A temperature sensor includes a constant current source and a transistor stack connected to the constant current source. The transistor stack includes a first transistor having a base connected to the constant current source and a collector coupled to a supply voltage. The collector of the first transistor is electrically isolated from the base of the first transistor. The transistor stack includes a second transistor connected to the first transistor. The second transistor has a collector connected to an emitter of the first transistor and has a base connected to the collector of the second transistor. The transistor stack includes an output node disposed between the constant current source and the base of the first transistor. A voltage of the output node is indicative of a temperature.

Temperature sensor

Methods are disclosed for forming an improved varactor diode having first and second terminals. The methods include providing a substrate having a first surface in which are formed isolation regions separating first and second parts of the diode. A varactor junction is formed in the first part with a first side coupled to the first terminal and a second side coupled to the second terminal via a sub-isolation buried layer (SIBL) region extending under the bottom and partly up the sides of the isolation regions to a further doped region that is ohmically connected to the second terminal. The first part does not extend to the SIBL region. The varactor junction desirably comprises a hyper-abrupt doped region. The combination provides improved tuning ratio, operating frequency and breakdown voltage of the varactor diode while still providing adequate Q.

Methods for forming varactor diodes

An improved varactor diode () having first () and second () terminals is obtained by providing a substrate () having a first surface () in which are formed isolation regions () separating first () and second () parts of the diode (). A varactor junction () is formed in the first part () and having a first side () coupled to the first terminal () and a second side () coupled to the second terminal () via a sub-isolation buried layer (SIBL) region () extending under the bottom () and partly up the sides () of the isolation regions () to a further doped region () ohmically connected to the second terminal (). The first part () does not extend to the SIBL region (). The varactor junction () desirably comprises a hyper-abrupt doped region (). The combination provides improved tuning ratio, operating frequency and breakdown voltage of the varactor diode () while still providing adequate Q.

Varactor structures

A semiconductor structure (,) having device isolation structures (,) and shielding structures (,). The shielding structures (,) are formed in a semiconductor material (,) and the device isolation structures (,) are formed within the corresponding shielding structures (,). A noise generating device is formed within a first shielding structure (,) and a noise sensitive device is formed within a second shielding structure (,). The two shielding structures (,) are grounded and prevent noise from the noise generating device from interfering with the noise sensitive device.

Semiconductor structure and method of manufacture

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Phoenix, AZ, United States of America

David Gareth Morgan