Abstract: A micro-light emitting diode (uLED) device comprises: a mesa comprising: a plurality of semiconductor layers including an n-type layer, an active layer, and a p-type layer; a p-contact layer contacting the p-type layer; a cathode contacting the first sidewall of the n-type layer; a first region of dielectric material that insulates the p-contact layer, the active layer, and a first sidewall of the p-type layer from the cathode; an anode contacting the top surface of the p-contact layer; and a second region of dielectric material that insulates the active layer, a second sidewall of the p-type layer, and the second sidewall of the n-type layer from the anode. The top surface of the p-contact layer has a different planar orientation compared to the first and second sidewalls of the n-type layer. Methods of making and using the uLED devices are also provided.

Abstract: A fast-settling digital automatic gain control circuit comprises first and second gain-controllable amplifiers in series. Each amplifier can be digitally switched between minimum and maximum gains by control logic that receives inputs from a multi-level voltage comparator. A peak detector connected to the output of the first gain-controlled amplifier is used to set the overall operating ranges for several threshold detectors. Four reference voltages are generated from the peak detector. The highest reference voltage is used to clock and reset the gain control logic with a hysteresis comparator to the instantaneous input signal from the first gain-controlled amplifier. The three other lower reference voltages are used to provide three-bits of digital input data to the gain control logic. Two digital controls are output, a min/max gain bit for the first gain-controlled amplifier, and a similar min/max gain bit for the second gain-controlled amplifier.

Abstract: An optical receiver has a voltage supply, a first node, and a second node. A first input of a differential amplifier is coupled to the first node and a second input of the differential amplifier is coupled to the second node. A photodetector is coupled between the voltage supply and the first node, which produces a photodetector capacitance. A programmable variable capacitor having a capacitance selectively matched to the photodetector capacitance is coupled between the voltage supply and the second node.

Abstract: A circuit that protects against electrostatic discharge and electrical over stress is provided. The circuit includes a first transistor including a substrate. An internal predetermined voltage source biases the substrate of the first transistor. The internal predetermined voltage source is greater than or equal to a source voltage provided to a source of the first transistor and isolates a substrate voltage of the first transistor from a supply voltage of the circuit. A first resistor is coupled to a gate of the first transistor and ground. The circuit also includes a zener diode coupled between ground and the supply voltage of the circuit. The zener diode shorts to ground if the supply voltage of the circuit exceeds the breakdown voltage of the zener diode.

Abstract: An optical receiver includes a photodetector coupled to a gain section having a variable gain stage. The gain stage provides an output voltage signal. A digital automatic gain control circuit is coupled to the output voltage signal and provides a digital output value to at least the variable gain stage. The gain of the variable gain stage is set according to the digital output value.

Abstract: A circuit has a voltage source, a node, a photodiode electrically coupled between the voltage source and the node, a voltage reference, a resistor electrically coupled between the node and the voltage reference, and a voltage clamp electrically connected to the node.