According to one embodiment of the present invention, provided is an analog to digital converter. The analog-to-digital converter according to one embodiment of the present invention comprises an analog amplification unit and a flash conversion unit, wherein the analog amplification unit may have a structure in which in which two input terminal circuits that alternately operate share a single amplifier. Accordingly, the analog-to-digital converter according to one embodiment of the present invention can be implemented in a smaller area and operate at low power, and can have a high resolution while operating at a high speed.

This application relates an activity detector (100) for detecting signal activity in an input audio signal (S.sub.IN), such as may be used for always-on speech detection. The activity detector has a first time-encoding modulator (TEM) 101 including a first hysteretic comparator (201) for generating a PWM (pulse-width modulation) signal based on the input audio signal. A second TEM (103) having a second hysteretic comparator (401) is arranged to receive a reference voltage (V.sub.MID) and generate a clock signal (S.sub.CLK). A time-decoding converter (102) receives the clock signal and generates count values of a number of cycles of the clock signal in periods defined by the PWM signal. An activity monitor (104) is responsive to a count signal (S.sub.CT) from the TDC 102 to determine whether the input audio signal comprises signal activity above a defined threshold.

This application relates an activity detector (100) for detecting signal activity in an input audio signal (S.sub.IN), such as may be used for always-on speech detection. The activity detector has a first time-encoding modulator (TEM) 101 including a first hysteretic comparator (201) for generating a PWM (pulse-width modulation) signal based on the input audio signal. A second TEM (103) having a second hysteretic comparator (401) is arranged to receive a reference voltage (V.sub.MID) and generate a clock signal (S.sub.CLK). A time-decoding converter (102) receives the clock signal and generates count values of a number of cycles of the clock signal in periods defined by the PWM signal. An activity monitor (104) is responsive to a count signal (S.sub.CT) from the TDC 102 to determine whether the input audio signal comprises signal activity above a defined threshold.

Systems and methods for interrogating sensing systems utilising bursts of samples. Bursts of samples correspond to optical pulses returning from optical sensors, where pulses are spaced at a period significantly longer than the pulse width, giving irregular sample spacing. The interrogation system and method processes the irregular busts of samples to recover phase information from received signals.

A radiation apparatus and a radiation signal processing method are provided. To elaborate, the apparatus includes an input unit including a radiation detector; an amplification unit configured to amplify a signal input through the radiation detector; a bipolar signal generation unit configured to generate a bipolar signal by converting the amplified signal; and a comparison unit configured to output a digital signal on the basis of comparison results of the bipolar signal with a preset first threshold value and a preset second threshold value. Herein, the comparison unit includes a first comparator configured to output a digital pulse in an interval where the bipolar signal is larger than the first threshold value and a second comparator configured to output a digital pulse in an interval where the bipolar signal is smaller than the second threshold value.

The present disclosure relates to a comparator, an AD converter, a solid-state image pickup device, an electronic device, a method of controlling the comparator, a data writing circuit, a data reading circuit, and a data transferring circuit, capable of improving the determining speed of the comparator and reducing power consumption. The comparator includes: a differential input circuit configured to operate with a first power supply voltage, the differential input circuit configured to output a signal when an input signal is higher than a reference signal in voltage; a positive feedback circuit configured to operate with a second power supply voltage lower than the first power supply voltage, the positive feedback circuit being configured to accelerate transition speed when a compared result signal indicating a compared result between the input signal and the reference signal in voltage, is inverted, on the basis of the output signal of the differential input circuit; and a voltage conversion circuit configured to convert the output signal of the differential input circuit into a signal corresponding to the second power supply voltage. The present disclosure can be applied to, for example, a comparator of a solid-state image pickup device.

The present disclosure relates to a comparator, an AD converter, a solid-state image pickup device, an electronic device, a method of controlling the comparator, a data writing circuit, a data reading circuit, and a data transferring circuit, capable of improving the determining speed of the comparator and reducing power consumption. The comparator includes: a differential input circuit configured to operate with a first power supply voltage, the differential input circuit configured to output a signal when an input signal is higher than a reference signal in voltage; a positive feedback circuit configured to operate with a second power supply voltage lower than the first power supply voltage, the positive feedback circuit being configured to accelerate transition speed when a compared result signal indicating a compared result between the input signal and the reference signal in voltage, is inverted, on the basis of the output signal of the differential input circuit; and a voltage conversion circuit configured to convert the output signal of the differential input circuit into a signal corresponding to the second power supply voltage. The present disclosure can be applied to, for example, a comparator of a solid-state image pickup device.

An analog-to-digital converter, including a sample/hold circuit; a reference voltage driver; a digital-to-analog converter; a comparator; and a logic circuit, wherein the reference voltage driver includes: a first voltage supplier circuit configured to output an external supply voltage provided from outside of the analog-to-digital converter; a second voltage supplier circuit configured to output a sampled reference voltage that is obtained during a sampling phase based on control signals received from the logic circuit; and a switching driver configured to electrically connect the first voltage supplier circuit to the digital-to-analog converter during a first conversion phase after the sampling phase based on the control signals received from the logic circuit, and to electrically connect the second voltage supplier circuit to the digital-to-analog converter during a second conversion phase based on the control signals received from the logic circuit.

An analog-to-digital converter, including a sample/hold circuit; a reference voltage driver; a digital-to-analog converter; a comparator; and a logic circuit, wherein the reference voltage driver includes: a first voltage supplier circuit configured to output an external supply voltage provided from outside of the analog-to-digital converter; a second voltage supplier circuit configured to output a sampled reference voltage that is obtained during a sampling phase based on control signals received from the logic circuit; and a switching driver configured to electrically connect the first voltage supplier circuit to the digital-to-analog converter during a first conversion phase after the sampling phase based on the control signals received from the logic circuit, and to electrically connect the second voltage supplier circuit to the digital-to-analog converter during a second conversion phase based on the control signals received from the logic circuit.

Technologies are provided for time-to-digital conversion without reliance on a clocking signal. Some embodiments of the technologies include a clockless TDC apparatus that can map continuous pulse-widths to binary bits represented via an iterative chaotic map (e.g., tent map, Bernoulli shift map, or similar). The clockless TDC apparatus can convert separated pulses to a single asynchronous digital pulse that turns on when a sensor detects a first pulse and turns off when the sensor detects a second pulse. The asynchronous digital pulse can be iteratively stretched and folded in time according to the chaotic map. The clockless TDC can generate a binary sequence that represents symbolic dynamics of the chaotic map. The process can be implemented by using an iterative time delay component until a precision of the binary output is either satisfied or overwhelmed by noise or other structural fluctuations of the TDC apparatus.