Intersil Americas Inc.

Micrel, Incorporated

Wendy Ng

Xijian Lin

Charles Vinn

Phillip J Benzel

Ramesh Selvaraj

Zhong Li

Oleg Steciw

In an embodiment, a proximity sensor includes a driver, a photo-diode (PD) and an analog-to-digital converter (ADC). The proximity sensor can also include a controller to control the driver. The driver selectively drives a light source, e.g., an infrared (IR) light emitting diode (LED). The PD, which produces a current signal indicative of the intensity of light detected by the PD, is capable of detecting both ambient light and light produced by the light source that is reflected off an object. The ADC receives one or more portion of the current signal produced by the PD. The ADC produces one or more digital output that can be used to estimate the proximity of an object to the PD in a manner that compensates for ambient light detected by the PD and transient changes to the detected ambient light.

Proximity sensors and methods for sensing proximity

One embodiment of the invention is a hybrid boost regulator that includes a conventional boost regulator chip that operates when its input voltage is above 2.5 volts and a pre-boost circuit that operates when its input voltage is above 1 volt. A single 1.5 volt battery may be used to power the hybrid boost regulator. The pre-boost circuit is connected to the voltage input terminal of the boost regulator chip. The pre-boost circuit boosts the battery voltage (e.g., 1.5v) at an output terminal of the hybrid boost regulator to approximately the minimum operating voltage (e.g., 2.5v) of the boost regulator chip. Since this pre-boosted voltage is applied to the voltage input terminal of the boost regulator chip, the boost regulator chip will become operational when the ramping output voltage of the hybrid boost regulator exceeds about 2.5 volts. Once the boost regulator chip is operational, the pre-boost circuit is then turned off, and the boost regulator chip runs off the 1.5 volt power supply to ramp up the output voltage to the full regulated voltage.

Extending the voltage operating range of boost regulators

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San Jose, CA, United States of America

Wendy Ng