The present disclosure relates to a solid state image sensor and an electronic apparatus capable of performing a gain transition at high speed. A ramp generation circuit includes sample hold circuits and ramp generation DACs, the number of which depends on kinds of required gains (for example, two kinds, i.e. a low gain and a high gain). Then, the two sample hold circuits can individually hold gain DAC output voltages at the different gains. This enables a switch to the ramp generation DAC holding the required gain voltage by means of a ramp selection signal. The present disclosure can be applied, for example, to a CMOS solid state image sensor that is used for an imaging device.

Apparatus and methods for a digital-to-time converter (DTC) are provided. In an example, a DTC can include a phase interpolator and a ring oscillator. The phase interpolator can be configured to receive digital representations of two or more distinct phase signals, and to interpolate the digital representations of the two or more distinct phase signals to provide an interpolated output phase signal. The ring oscillator can be configured to receive the interpolated phase signal, to lock on to a frequency and a phase of the interpolated output phase signal, and to provide a filtered phase signal.

Apparatus and methods for a digital-to-time converter (DTC) are provided. In an example, a DTC can include a phase interpolator and a ring oscillator. The phase interpolator can be configured to receive digital representations of two or more distinct phase signals, and to interpolate the digital representations of the two or more distinct phase signals to provide an interpolated output phase signal. The ring oscillator can be configured to receive the interpolated phase signal, to lock on to a frequency and a phase of the interpolated output phase signal, and to provide a filtered phase signal.

The present disclosure provides a reference clock signal injected phase locked loop circuit and an offset calibration method. The reference clock signal injected phase locked loop circuit includes a first pulse generator, a second pulse generator, a state machine, a pulse selection and amplification circuit, a voltage controlled delay line, a phase detector, and a filter, and forms an offset calibration loop, a phase locked loop, a voltage controlled oscillator loop, and an injection locked loop. The state machine disconnects the phase locked loop and the voltage controlled oscillator loop and enables the offset calibration loop to calibrate the phase detector; the state machine enables the phase locked loop and the voltage controlled oscillator loop and locks a signal of the second pulse generator; and the state machine enables the injection locked loop for injecting a first pulse signal of the first pulse generator.

Techniques regarding error detection in one or more generated signals based on one or more signal-to-noise ratios are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a signal analysis component that can determine a signal-to-noise ratio associated with a generated signal, wherein the signal-to-noise ratio incorporates a signal value based on a reference signal and a noise value based on a difference between the reference signal and an acquired signal.

Techniques regarding error detection in one or more generated signals based on one or more signal-to-noise ratios are provided. For example, one or more embodiments described herein can comprise a system, which can comprise a memory that can store computer executable components. The system can also comprise a processor, operably coupled to the memory, and that can execute the computer executable components stored in the memory. The computer executable components can comprise a signal analysis component that can determine a signal-to-noise ratio associated with a generated signal, wherein the signal-to-noise ratio incorporates a signal value based on a reference signal and a noise value based on a difference between the reference signal and an acquired signal.

A DTC circuit, includes: a DAC connected to a first node; a first switch connected between a first power source and a second node, and to provide a charge current to the second node according to a first switching signal; and a second switch connected between the first node and the second node, and to electrically connect the DAC to the second node according to a second switching signal. The DAC is to be charged to generate a voltage ramp corresponding to the charge current during a first DTC operational phase when the first and second switching signals have an active level to turn on the first and second switches, and to generate an input control word dependent voltage according to an input control word during a second DTC operational phase when the first and second switching signals have an inactive level to turn off the first and second switches.

With respect to a phase locked loop (PLL) circuit that receives a first reference clock and generates an output clock, the PLL circuit includes a delay circuit that delays the first reference clock to generate a second reference clock, a feedback circuit that generates a control signal based on a phase difference between the second reference clock and a feedback clock, an oscillator that oscillates at a frequency determined based on the control signal to generate the output clock, and a divider that divides the output clock in the on state. The PLL circuit switches between a first mode and a second mode, the feedback clock in the first mode is a signal obtained by retiming an output of the divider with the output clock, and the feedback clock in the second mode is a signal obtained by retiming the first reference clock with the output clock.

With respect to a phase locked loop (PLL) circuit that receives a first reference clock and generates an output clock, the PLL circuit includes a delay circuit that delays the first reference clock to generate a second reference clock, a feedback circuit that generates a control signal based on a phase difference between the second reference clock and a feedback clock, an oscillator that oscillates at a frequency determined based on the control signal to generate the output clock, and a divider that divides the output clock in the on state. The PLL circuit switches between a first mode and a second mode, the feedback clock in the first mode is a signal obtained by retiming an output of the divider with the output clock, and the feedback clock in the second mode is a signal obtained by retiming the first reference clock with the output clock.

A digital-to-time converter (DTC) converts a digital code into a time delay using a capacitor digital-to-analog converter (CDAC) that functions as a charging capacitor. The DTC includes a switched capacitor voltage-to-current converter for the formation of a charging current (or a discharging current) for charging (or for discharging) the charging capacitor responsive to a triggering clock edge that begins the time delay. A comparator compares a voltage on the charging capacitor to a threshold voltage to determine an end of the time delay.