Abstract: An image sensor comprises an array of pixels comprising: a pinned photodiode; a first sense node A; a second sense node B; a transfer gate TX connected between the pinned photodiode and the first sense node A; a first reset transistor M3 connected between a voltage reference line Vrst and the second sense node B; a second reset transistor M4 connected between the first sense node A and the second sense node B; and a buffer amplifier M1 having an input connected to the first sense node A. The control logic is arranged to operate the pixels in a low conversion gain mode and in a high conversion gain mode. In each of the conversion gain modes the control logic is arranged to operate one of a first reset control line RS1 and a second reset control line RS2 to continuously switch on one of the first reset transistor M3 and the second reset transistor M4 during a readout period of an operational cycle of the pixels.

Abstract: An image sensor comprises a first die with an array of pixels and a second die. The first die and second die are stacked together. A first in-pixel part of an analog-to-digital converter (ADC) outputs at least one current signal. The first in-pixel part of the ADC is a Differential Transconductance Amplifier includes a first differential input for receiving the analog signal and a second differential input for receiving a reference signal. There is at least one output bus connected between the first in-pixel part of the ADC on the first die and the second part of the ADC on the second die. The first part of the ADC is adapted to output the at least one current signal to the at least one output bus, and the second part of the ADC is adapted to receive the at least one current signal and to generate a digital signal.

Abstract: A pixel structure comprises an epitaxial layer (1) of a first conductivity type. A photo-sensitive element comprises a first region (4) of a second conductivity type and a second region (3) of the first conductivity type positioned between the epitaxial layer (1) and the first region (4). A charge storage node (ø2) is arranged to store charges acquired by the photo-sensitive element, or to form part of a charge storage element. A third region (2) of the second conductivity type is positioned between the charge storage node and the epitaxial layer. The pixel structure further comprises a charge-to-voltage conversion element (13) for converting charges from the charge storage node to a voltage signal and an output circuit (21, 22) for selectively outputting the voltage signal from the pixel structure.

Abstract: An image sensor comprises a first die with an array of pixels and a second die. The first die and second die are stacked together. A first in-pixel part of an analog-to-digital converter (ADC) outputs at least one current signal. The first in-pixel part of the ADC is a Differential Transconductance Amplifier includes a first differential input for receiving the analog signal and a second differential input for receiving a reference signal. There is at least one output bus connected between the first in-pixel part of the ADC on the first die and the second part of the ADC on the second die. The first part of the ADC is adapted to output the at least one current signal to the at least one output bus, and the second part of the ADC is adapted to receive the at least one current signal and to generate a digital signal.

Abstract: A pixel array for imaging comprises an array of pixels of a first pixel type and a second pixel type. Each pixel of the first pixel type comprises a first photo-sensitive element having a first area. Each pixel of the second pixel type comprises a second photo-sensitive element and a third photo-sensitive element. The second photo-sensitive element has a second area, which is smaller than the first area. Only the second photo-sensitive element in the pixel of the second pixel type is connected to a readout circuit. The third photo-sensitive element is connected to a charge drain via a permanent connection or a switchable connection. Outputs of the second photo-sensitive elements can be used to perform phase detect autofocussing.

Abstract: An analog-to-digital converter for generating an output digital value equivalent to the difference between a first analog signal level (Vres) and a second analog signal level (Vsig) comprises at least one input for receiving the first analog signal level and the second analog signal level, an input for receiving a ramp signal and an input for receiving at least one clock signal. A set of N counters, where N?2, are arranged to use N clock signals which are offset in phase from one another. A control stage is arranged to enable the N counters based on a comparison of the ramp signal with the first analog signal level (Vres) and the second analog signal level (Vsig). An output stage is arranged to output the digital value which is a function of values accumulated by the N counters during a period when they are enabled.

Abstract: An analog-to-digital conversion apparatus 10 comprises a plurality of analog-to-digital converters 30 and a ramp generator 20. Each of the analog-to-digital converters 30 comprises an analog signal input for receiving an analog signal level and a ramp signal input. A control stage is arranged to compare the ramp signal with the analog signal level and, based on the comparison, to enable a counter provided at the analog-to-digital converter or to latch a digital value received from a counter. The control stage comprises a comparator in the form of a first differential amplifier with a first branch connected to the input for receiving the ramp signal, a second branch connected to the analog signal input and an output, and a biasing current source for biasing the first differential amplifier. A feedback circuit controls the biasing current source.

Abstract: An analog-to-digital conversion apparatus 10 comprises a plurality of analog-to-digital converters 30 and a ramp generator 20. Each of the analog-to-digital converters 30 comprises an analog signal input for receiving an analog signal level and a ramp signal input. A control stage is arranged to compare the ramp signal with the analog signal level and, based on the comparison, to enable a counter provided at the analog-to-digital converter or to latch a digital value received from a counter. The control stage comprises a comparator in the form of a first differential amplifier with a first branch connected to the input for receiving the ramp signal, a second branch connected to the analog signal input and an output, and a biasing current source for biasing the first differential amplifier. A feedback circuit controls the biasing current source.

Abstract: A pixel structure comprises an epitaxial layer (1) of a first conductivity type. A photo-sensitive element comprises a first region (4) of a second conductivity type and a second region (3) of the first conductivity type positioned between the epitaxial layer (1) and the first region (4). A charge storage node (ø2) is arranged to store charges acquired by the photo-sensitive element, or to form part of a charge storage element. A third region (2) of the second conductivity type is positioned between the charge storage node and the epitaxial layer. The pixel structure further comprises a charge-to-voltage conversion element (13) for converting charges from the charge storage node to a voltage signal and an output circuit (21, 22) for selectively outputting the voltage signal from the pixel structure.