A digitally controlled delay line (DCDL) includes input and output terminals, and a plurality of stages that propagate a signal along a first signal path from the input terminal to a selectable return stage and along a second signal path from the return stage to the output terminal. Each stage includes a first inverter that selectively propagates the signal along the first signal path, a second inverter that selectively propagates the signal along the second signal path, and a third inverter that selectively propagates the signal from the first signal path to the second signal path. At least one of the first or third inverters includes a tuning portion including either a plurality of parallel, independently controllable p-type transistors coupled in series with a single independently controllable n-type transistor, or a plurality of parallel, independently controllable n-type transistors coupled in series with a single independently controllable p-type transistor.

A comparator circuit includes a first comparator configured to receive input of an input signal and a comparison target signal to be compared with the input signal, a first output stage including an N-channel transistor having a control terminal to which a first control terminal voltage output from the first comparator is applied, and a first clamp unit configured to limit the first control terminal voltage to be not higher than a first predetermined voltage that is higher than a first threshold voltage of the N-channel transistor but is lower than a first high side voltage output as high level from the first comparator when the first control terminal voltage is not limited.

A disclosed comparator includes a comparison circuit including a differential unit that compares an input signal with a reference signal and changes a level of a signal output to a first node in accordance with a result of comparison and an amplifier unit that includes a load element and outputs a signal in accordance with a potential of the first node to a second node, and a positive feedback circuit that is connected to the second node and a third node and changes a level of a signal at the third node at a rate higher than a change rate of a level of a signal at the second node in accordance with a change in a level of a signal at the second node.

The present technology relates to a comparator that can easily modify operating point potential of the comparator, and an imaging device. A pixel signal output from a pixel, and, a reference signal with changeable voltage are input to a differential pair. A current mirror connected to the differential pair, and a voltage drop mechanism allowed to cause a predetermined voltage drop is connected between a transistor that configures the differential pair, and a transistor that configures the current mirror. A switch is connected in parallel to the voltage drop mechanism. The present technology can be applied, for example, to an image sensor that captures an image.

Varactors may be employed to enable enhanced performance and/or reduced power consumption of integration-based voltage comparators. One illustrative voltage comparator includes: a latch having two sense transistors to set a latch to either of two complementary states; two varactors each coupled to enable one of the two sense transistors upon reaching a turn on voltage; and a differential amplifier to charge or discharge the two varactors at a differential rate proportional to a difference in input voltages. An illustrative voltage comparison method includes: converting two input voltages into two respective currents; applying each of the two respective currents to one of two respective varactors; and deriving a latch state from the varactor voltages, the latch state indicating which of the two input voltages is greater.

A low power comparator and a self-regulated device for adjusting power saving level of an electronic device are provided. The low power comparator includes an input differential pair circuit, a self-regulated device, and a tail current switch. The input differential pair circuit is configured to receive input signals to be compared. The self-regulated device is coupled to the input differential pair circuit and includes a self-regulated circuit which has a first transistor with a first threshold voltage and a second transistor with a second threshold voltage and is configured to adjust a power saving level of the low-power comparator according to the first threshold voltage and the second threshold voltage. The tail current switch is coupled to the input differential pair circuit through the self-regulated circuit to provide a constant current to the input differential pair circuit.

A semiconductor sensing device generates an output based on a sensor. A connection point of an output circuit constituted by first and second switching output elements connected so as to be complementary is connected to an output terminal. Between the first switching output element and the connection point of the output circuit, a first switching element is connected. Between the second switching output element and the connection point of the output circuit, a second switching element is connected. When voltage of the output terminal is a voltage lower than a lower limit clamp voltage, the first switching element turns OFF. When the voltage of the output terminal is a voltage higher than an upper limit clamp voltage, the second switching element turns OFF.

A semiconductor device with low power consumption can be provided. The semiconductor device includes a differential circuit and a latch circuit, the differential circuit includes a transistor including an oxide semiconductor in a channel formation region, and the latch circuit includes a transistor including a single semiconductor or a compound semiconductor in a channel formation region. The differential circuit and the latch circuit include an overlap region.

A comparator includes a first-stage op amp circuit, a second-stage op amp circuit, a bias circuit and a clamping circuit. The first-stage op amp circuit includes two voltage input terminals and a voltage output terminal; the second-stage op amp circuit is connected with the bias circuit and the voltage output terminal of the first-stage op amp circuit; and the clamping circuit is connected with the voltage output terminal of the first-stage op amp circuit. By adding a clamping circuit in the comparator, the highest voltage at the voltage output terminal of the first-stage op amp circuit can be clamped to a preset voltage. During the operation of the comparator, the voltage change range of the voltage output terminal of the first-stage op amp circuit is smaller, which reduces the discharge delay of the voltage output terminal of the first-stage op amp circuit, thereby increasing the flip speed of the comparator.

A relaxation oscillator 2 comprises: a comparator 4 comprising: a differential pair of transistors 140, 142, 144. 40, 42, 44; a static current source 32; and a dynamic current source 32; and at least one energy storage component 8, 14;
wherein the comparator 4 is arranged to provide an output signal which triggers the charging or discharging of the energy storage component 8, the dynamic current source 32 being enabled prior to the charging or discharging being triggered and disabled after a predetermined time.