A back side illuminated image sensor may operate using the single-photon avalanche diode (SPAD) concept in a Geiger mode of operation for single photon detection. The image sensor may be implemented using two layer stacking with a silicon on insulator (SOI) chip. The chip-to-chip electrical connections between the top level image sensing chip and the second level ASIC circuit chip may be realized at each pixel with a single bump connection per pixel. A light level signal may be obtained from pixels that have photon counting capabilities while a distance measurement signal for 3-dimensional imaging may be obtained from pixels that have time-of-flight (ToF) detection capabilities. Both types of pixels may be integrated within the same array and use the same SPAD structure placed on the top chip.

A computing apparatus triggered by an edge of a supply-line signal with a pulse width counter includes: a clock circuit to supply clock signals to a pulse width counter from an output port of said clock circuit; said pulse width counter triggered by said clock signals to count the pulse width of a supply-line signal from a power supply line, to set a circuit status of said computing apparatus in accordance with said pulse width, and to output said circuit status to an edge-triggered computing unit; and the edge-triggered computing unit to do computing triggered by an edge of a supply-line signal, and to output computing result as the output of said computing apparatus in accordance with said circuit status. The circuit status of the computing apparatus is set in accordance with pulse width counter of supply-line signals.

A computing apparatus triggered by an edge of a supply-line signal with a pulse width counter includes: a clock circuit to supply clock signals to a pulse width counter from an output port of said clock circuit; said pulse width counter triggered by said clock signals to count the pulse width of a supply-line signal from a power supply line, to set a circuit status of said computing apparatus in accordance with said pulse width, and to output said circuit status to an edge-triggered computing unit; and the edge-triggered computing unit to do computing triggered by an edge of a supply-line signal, and to output computing result as the output of said computing apparatus in accordance with said circuit status. The circuit status of the computing apparatus is set in accordance with pulse width counter of supply-line signals.

According to one embodiment, a frequency divider circuit includes a 1st flip-flop including a 1st terminal to which a clock signal is input, and including a 2nd terminal to which a 1st signal is input; a 2nd flip-flop including a 1st terminal to which the clock signal is input, and including a 2nd terminal to which a 2nd signal is input, the 2nd signal being output from the 1st flip-flop; a 3rd flip-flop including a 1st terminal to which the clock signal is input, and including a 2nd terminal to which a 3rd signal is input, the 3rd signal being output from the 2nd flip-flop; and an exclusive OR gate including a 1st terminal to which the 4th signal is input, and including a 2nd terminal to which a 5th signal is input, the 5th signal being output from the 2nd flip-flop.

A circuit includes a counter circuit, a logic circuit, and a clock divider. The counter circuit includes a clock divider counter to be loaded with most significant bits of a divider value, and decremented at a same edge of each pulse of a clock signal. The logic circuit compares a value contained in the divider counter to a reference value and generates an end count signal as a function of the value contained in the divider counter matching the reference value, and transitions a toggle signal at a same edge of each pulse of the end count signal. The clock divider counter is reloaded with the most significant bits of the divider value as a function of the end count signal. The clock divider generates a divided version of the clock signal as a function of the toggle signal.

A semiconductor device includes a clock divider that receives a clock signal and generates even and odd clock signals. The clock signal includes a first frequency, while the even and odd clock signals each includes a second frequency that is half the first frequency. The semiconductor device also includes even and odd command paths coupled to the clock divider each having a set of logic and a set of flip-flops. The even command path receives a command and the even clock signal and outputs an even output signal. The odd command path receives the command and the odd clock signal and outputs an odd output signal. The semiconductor device also includes combination circuitry coupled to the even and odd command paths that combines the even and odd output signals.

A circuit for providing a fractional divider/multiplier using harmonic recombination may include a power amplifier, an oscillator coupled to the power amplifier, and a divider coupled to the oscillator. In one or more implementations, the divider is configured to generate one or more phases of a harmonic from the oscillator to reduce signal interference from the power amplifier. In one or more implementations, the divider includes a divide-by-M divider, where M is a positive integer, and an array of transconductance cells coupled to the output of the divide-by-M divider. In one or more implementations, the divider includes an inductor or a filter coupled to the output of the array of transconductance cells. In one or more implementations, the oscillator includes a logical gate and a resistor-capacitor circuit coupled in series feedback with a multi-stage ring oscillator. The oscillator may include a divider coupled to the multi-stage ring oscillator.

A clock divider includes, in part, a pair of counters and a programmable delay line. A first one of the counters operates at a first frequency and is configured to count using a first integer portion of the divisor. The second counter operates at a second frequency smaller than the first frequency and is configured to count using a second integer portion of the divisor. The programmable delay line includes, in part, a chain of delay elements configured to generate a multitude of delays of the output of the second counter. A multiplexer selects one of the generated delays in accordance with the fractional portion of the divisor. The second counter increases its count only when the first counter reaches a terminal count. The first and second integer portions are loaded respectively into the first and second counters when the second counter reaches its terminal count.

A system (and associated method) includes an input flip-flop, a counter, and a clock tree. The input flip-flop includes a clock input terminal configured to be coupled to a device clock, or a clock generated from a phase-locked loop, and a data input terminal configured to be coupled to a first reference signal. The input flip-flop is configured to use the device clock to latch the reference signal to produce a latched reference signal. The counter is configured to count pulses of the device clock starting upon detection of the latched reference signal and to output a second reference signal comprising a pulse for every L pulses of the device clock. The clock tree is configured to divide down the device clock to generate a first output clock. The clock tree is configured to be synchronized by a pulse of the second reference signal.

A method of sensing a temperature of a semiconductor device, includes: measuring, by a time measuring circuit, time until a count value, which is obtained from a counter by counting a first signal having a frequency corresponding to a first voltage, reaches a largest count value which can be counted by the counter; and obtaining, by the counter, a piece of digital information corresponding to the first voltage based on a count value obtained by counting a second signal having a frequency corresponding to a second voltage, which is different from the first voltage, based on the time measured by the time measuring circuit, the first voltage depending upon the temperature of the semiconductor device.