Abstract: A LED driving apparatus and an operating method thereof are disclosed. The LED driving apparatus includes a power, at least one LED string, a LED control unit, and an input voltage detection circuit. At least one LED string is coupled to the power and includes LEDs connected in series. The input voltage detection circuit is coupled to two ends of at least one LED of the LEDs respectively and used to judge whether an input voltage is lower than a LED conducting voltage. The input voltage detection circuit includes a charging capacitance to be charged when the at least one LED string is conducted. If the judged result of the input voltage detection circuit is yes, the input voltage detection circuit will control the charging capacitance having a charging voltage to discharge to the at least one LED string.

Abstract: A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a voltage generating module. The light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a preset voltage and an activation voltage and includes a light-emitting end, a control end, and a setting end. The light-emitting ends are coupled with the light-emitting units, and the setting ends of the switches are coupled with each other. The voltage generating module includes a plurality of control units and provides a plurality of control voltages to the switches, and each switch is driven to be activated or to be deactivated according to a relation of the preset voltage and a difference between the control voltage and the activation voltage when the input voltage drives the light-emitting units, the switches, and the control units.

Abstract: A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a bias current module, wherein the light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a reference voltage and a critical activation voltage and includes a light-emitting end and a bias end opposite to the light-emitting end, wherein the light-emitting end is coupled with the light-emitting units, and the bias ends of the switches are coupled with each other. The bias current module is coupled with the bias ends of the switches and has an operating bias voltage varying according to the frequency, wherein each switch is driven to be activated or to be deactivated according to a relation of the critical activation voltage and a difference between the reference voltage and the operating bias voltage.

Abstract: A LED driving apparatus and an operating method thereof are disclosed. The LED driving apparatus includes a power, at least one LED string, a LED control unit, and an input voltage detection circuit. At least one LED string is coupled to the power and includes LEDs connected in series. The input voltage detection circuit is coupled to two ends of at least one LED of the LEDs respectively and used to judge whether an input voltage is lower than a LED conducting voltage. The input voltage detection circuit includes a charging capacitance to be charged when the at least one LED string is conducted. If the judged result of the input voltage detection circuit is yes, the input voltage detection circuit will control the charging capacitance having a charging voltage to discharge to the at least one LED string.

Abstract: A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a voltage generating module. The light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a preset voltage and an activation voltage and includes a light-emitting end, a control end, and a setting end. The light-emitting ends are coupled with the light-emitting units, and the setting ends of the switches are coupled with each other. The voltage generating module includes a plurality of control units and provides a plurality of control voltages to the switches, and each switch is driven to be activated or to be deactivated according to a relation of the preset voltage and a difference between the control voltage and the activation voltage when the input voltage drives the light-emitting units, the switches, and the control units.

Abstract: A driving circuit includes a plurality of light-emitting units, a plurality of switches, and a bias current module, wherein the light-emitting units are coupled with each other in series and are driven with an input voltage varying according to a frequency. Each switch has a reference voltage and a critical activation voltage and includes a light-emitting end and a bias end opposite to the light-emitting end, wherein the light-emitting end is coupled with the light-emitting units, and the bias ends of the switches are coupled with each other. The bias current module is coupled with the bias ends of the switches and has an operating bias voltage varying according to the frequency, wherein each switch is driven to be activated or to be deactivated according to a relation of the critical activation voltage and a difference between the reference voltage and the operating bias voltage.

Abstract: An analog to digital converter for the conversion of an analog input signal to a digital output code of n bits has a plurality of voltage references created in a voltage reference generator that divides the total range of voltage of the conversion input into increments of voltage equal to the smallest increment of resolution. The n bits of digital output are divided into most significant bits and least significant bits. The most significant bits are encoded from a set of digital signals that are formed in a set of coarse comparators, that compare the analog input signal with a subset of the voltage references representing the coarse range. The digital code that is the output of the coarse comparators is used to determine the selection of the subset of the plurality of the voltage references that are the fine voltage references. The least significant bits are encoded from a set of digital signals that are formed in a set of fine comparators that compare the analog input signal to the fine voltage references.

Abstract: A low noise high-frequency clock generator using a low speed voltage controlled oscillator which includes 2m differential delay elements connected in series in an inverting configuration, where m is an integer greater than 0. The output of the 2mth delay element is coupled to the input of the first delay element in a non-inverting configuration. M 2-input exclusive NOR gates are provided wherein respective input pairs are taken from positive terminal inputs of adjacent delay elements. The clock generator also includes an m-input OR gate coupled to the m-outputs from the respective m exclusive NOR gates for generating the clock generator output signal. The delay elements have a variable delay associated therewith controlled by a control delay signal DCS. Changes in the delay associated with each delay element changes the frequency of the clock generator output signal wherein the output frequency is equal to 1/(2d), where d is the time delay associated with each delay element.