Analog Devices Global

Analog Devices,inc.

Hua-Jung Yang

Bin Shao

Yanfeng Lu

Suyi Yao

Janne Klemetti

Embodiments of the disclosure can provide an optical charging system with an integrated sensor and power receiver. An electronic device (e.g., a wearable) can include an optical sensor for performing photometric measurements. A photodiode of the sensor can be shared and used for generating an electrical signal when exposed to a light source (e.g., LED) of a light power transmitter. The electrical signal can be conditioned by a power management circuit and can be used to charge a device battery. The light power transmitter can include a photodiode, which can be used for establishing a connection with the device using an optical signal emitted by a light source of the optical sensor. The light power transmitter can be power by, e.g., a USB connection. The intensity of the power transmitter light source can be regulated via a feedback signal from the device, based on the battery charging status.

Optical charging system with integrated sensor and power receiver

Apparatus and techniques for controlling measurement of an electrical parameter of an energy source can be used to obtain information for use in enhancing a power transfer efficiency between the energy source and a load. For example, during a first measurement cycle, information indicative of the electrical parameter of the energy source can be obtained using a measurement circuit during a first sampling duration in which the load is decoupled from the energy source. The information indicative of the obtained electrical parameter can be compared to a threshold. In response to the comparing, a different second sampling duration can be determined for use in obtaining information indicative of the electrical parameter during a subsequent measurement cycle. The information indicative of the electrical parameter of the energy source includes information for use in enhancing the power transfer efficiency between the energy source and the load.

Sampling duration control for power transfer efficiency

A device to determine a state of a battery is disclosed. One or more transistors provide a resistance between first and second nodes. The one or more transistors are configured to conduct a supply current from a battery between the first node and the second node. A measurement circuit measures the voltage generated between the first node and the second node. The measurement circuit further measures the supply voltage. A calculation circuit generates an estimate of the supply current based on the voltage measured between the first node and the second node and the resistance of the one or more transistors. The calculation circuit generates an estimate of the state of charge of the battery based on the measured supply voltage and the estimate of the supply current.

Voltage-based fuel gauge on battery capacity

An apparatus comprises an output port for a circuit load, a first input port for an energy harvest source, an input/output port a second energy source, a first circuit path from the energy harvest source to the second energy source at the input/output port and to the variable load at the output port, a second circuit path from the second energy source to the output port, a cold start circuit that produces a first voltage level at the output port by charging a capacitor at the output port using energy of the energy harvest source, and a main converter circuit that produces a second regulated voltage level at the input/output port using energy of the energy harvest source when the voltage at the output port capacitor is above a specified voltage value and uses the energy of the capacitor at the output port during startup of the main converter circuit.

Growing community of inventors

Santa Clara, CA, United States of America

Hua-Jung Yang