Lite-on Singapore Pte. Ltd.

Avago Technologies Ecbu IP (singapore) Pte. Ltd.

John Julius De Leon Asuncion

Tong-Tee Tan

Kok-Soon Yeo

Lian-Chun Xu

Chee-Keong Teo

Seng-Yee Chua

Wai-Keat Tai

Lee-Cheng Tay

Jiaqi Sun

Prabakaran Chinnusamy

A fault detector circuit is provided for detecting or controlling any signal related to a laser emitter in an electronic device. The fault detector circuit includes a first NMOS transistor and a comparator. A drain of the first NMOS transistor is coupled to a first supply voltage through the laser emitter. A gate of the first NMOS transistor is coupled to a control voltage. A source of the first NMOS transistor is grounded. The comparator is coupled to the drain of the first NMOS transistor and a reference voltage. The comparator compares a voltage of the drain of the first NMOS transistor with the reference voltage to generate a first detecting signal for determining whether or not the first supply voltage of the laser emitter needs to be cut off.

Fault detector circuit

A method for ambient light subtraction providing a sensor having an emitter, a receiver, and a processor; performing a first sampling process, during which the emitter does not emit signals, the receiver receives a first ambient light signal converted into a first data set by the processor; performing a second sampling process, during which the emitter emits a detecting signal, the receiver receives a second ambient light signal and the detecting signal converted into a second data set by the processor; performing a third sampling process, during which the emitter does not emit signals, the receiver receives a third ambient light signal converted into a third data set by the processor; deriving an average value by calculating the average of the first data set and the third data set; and deriving a difference value by calculating the difference between the second data set and the average value.

Method for ambient light subtraction

A stacked photodiode structure comprises a first-conductivity-type substrate, a second-conductivity-type well region and a first-conductivity-type well region. The first-conductivity-type substrate has a first surface for light incidence and a grounding terminal. The second-conductivity-type well region is formed in the first-conductivity-type substrate and adjacent to the first surface. The first-conductivity-type well region is formed in the second-conductivity-type well region and adjacent to the first surface. A PN junction between the first-conductivity-type well region and the second-conductivity-type well region generates free electrons responsive to visible light spectrum. A PN junction between the second-conductivity-type well region and the first-conductivity-type substrate generates free holes and free electrons responsive to mainly IR light. The difference between a first photocurrent generated from an anode terminal of the first-conductivity-type well region and a second photocurrent generated from a cathode terminal of the second-conductivity-type well region represents the intensity of incident IR light.

Ambient light sensing with stacked photodiode structure with dual PN junction

An exemplary embodiment of the present disclosure illustrates a proximity sensing method used in a controller of a proximity sensing device. Firstly, a cross talk value is initialized. After the cross talk value is initialized, whether the cross talk value should be updated is judged at least according to a first sensing value currently received from a sensing unit of the proximity sensing device. When the cross talk value is judged to be updated, the cross talk value is updated at least according to a first sensing value. Then, a compensated sensing value is obtained by subtracting the cross talk value from the first sensing value.

Proximity sensing method, proximity sensing device, and electronic device thereof

In one embodiment, an optical transducer, such as an infrared transducer, generates an output signal that is representative of optical irradiance. A noise control circuit is coupled in a power supply path of the optical transducer. A switching circuit varies the noise control provided by the noise control circuit, in response to changes in the output signal of the optical transducer. The noise control may be varied in a number of different ways, including: turning the noise control on or off, varying the noise control in discrete steps, or varying the noise control in a continuous manner. Methods for varying noise control in response to optical irradiance of an optical transducer are also disclosed.

Variable noise control for an optical transducer

In one embodiment, a comparator is provided with a first differential input stage that receives an input voltage and a reference voltage and produces a first differential output, and a second differential input stage that has differential inputs and produces a second differential output. A comparator stage produces a comparator output in response to the first and second differential outputs. The comparator also has a hysteresis control circuit, the components of which include 1) a resistor and a hysteresis regulating voltage input, coupled between the differential inputs of the second differential input stage, 2) first and second current generators, and 3) at least one switch, under control of the comparator output, to alternately enable different combinations of the first and second current generators, thereby inducing a first or a second current through the resistor.

Growing community of inventors

Singapore, Singapore

John Julius De Leon Asuncion