An image sensor includes a pixel array including first pixels and second pixels, each of the first and second pixels including photodiodes, a sampling circuit detecting a reset voltage and a pixel voltage from the first and second pixels and generating an analog signal, an analog-to-digital converter image data from the analog signal, and a signal processing circuit generating an image using the image data. Each of the first pixels includes a first conductivity-type well separating the photodiodes and having impurities of a first conductivity-type. The photodiodes have impurities of a second conductivity-type different from the first conductivity-type. Each of the second pixels includes a second conductivity-type well separating the photodiodes and having impurities of the second conductivity-type different from the first conductivity-type. A potential level of the second conductivity-type well is higher than a potential level of the first conductivity-type well.

This application relates to ADC circuitry. An ADC circuit (200) has first and second conversion paths (201a, 201b) for converting analogue signals to digital and is operable in first and second modes. In the first mode, the first and second conversion paths are connected to respective first and second input nodes (202a, 202b) to receive and convert full scale first and second analogue input signals (Ain1, Ain2) to separate digital outputs (Dout1, Dout2). In the second mode, the first and second conversion paths are both connected to the first input node (202a), to convert the first analogue input signal (Ain1) to respective first and second digital signals, and the first and second conversion paths are configured for processing different signal levels of the first analogue input signal. A selector (207) select the first digital signal or the second digital to be output as an output signal based on an indication of amplitude of the first analogue input signal.

An architecture for a chopper stabilized multiplier-accumulator (MAC) uses a chop clock and common Unit Element (UE), the MAC formed as a plurality of MAC UEs receiving X and W values and a sign bit exclusive ORed with the chop clock, a plurality of Bias UEs receiving E value and a sign bit exclusive ORed with the chop clock, and a plurality of Analog to Digital Conversion (ADC) UEs which collectively perform a scalable MAC operation and generate a binary result. Each MAC UE, BIAS UE and ADC UE comprises groups of NAND gates with complementary outputs arranged in NAND-groups, each NAND gate coupled to a differential charge transfer bus through a binary weighted charge transfer capacitor. The analog charge transfer bus is coupled to groups of ADC UEs with an ADC controller which enables and disables the ADC UEs using successive approximation to determine the accumulated multiplication result.

A solid-state imaging device capable of suppressing variations in reference voltages and improving performance of reference voltages is provided. According to one embodiment, the solid-state imaging device includes a pixel outputting a luminance signal voltage corresponding to an amount of incident light, reference voltages, a reference voltage generation circuit outputting a ramp signal and an inverse ramp signal, and an AD converter, and the AD converter includes a comparator including an amplifier coupled to one input terminal, a reference voltage and an input terminal coupled to each of the ramp signals via a capacitor, and an input terminal coupled to each of the reference voltage and the ramp signal via a capacitor, and a ramp current cancel circuit coupled to each of the reference voltages via a cancel capacitor.

A neural network circuit is described that includes a first sample-and-hold circuit, a reference voltage generation circuit, a first comparator circuit, and a first output circuit. The first sample-and-hold circuit generates a first analog voltage based on a first output current output by a first neural network computation array. The reference voltage generation circuit generates a reference voltage based on a first control signal. The first comparator circuit is connected to the first sample-and-hold circuit and the reference voltage generation circuit, and outputs a first level signal based on the first analog voltage and the reference voltage. The first output circuit samples the first level signal based on a second control signal, and outputs a first computation result that meets the first computation precision.

A pipeline analog to digital converter includes converter circuitries and a calibration circuitry. The converter circuitries sequentially convert an input signal into a plurality of first digital codes, in which a first converter circuitry in the converter circuitries is configured to perform a quantization according to a first signal to generate a first corresponding digital code in the first digital codes, and the first signal is a signal, which is processed by the first converter circuitry, of the input signal and a previous stage residue signal. The calibration circuitry combines the first digital codes to output a second digital code, detects whether the quantization is completed to generate control signals, and determines whether to set the second digital code to be a second corresponding digital code in predetermined digital codes according to the control signals.

A pipeline analog to digital converter includes converter circuitries and a calibration circuitry. The converter circuitries sequentially convert an input signal into first digital codes. A first converter circuitry in the converter circuitries performs a quantization according to a first signal to generate a first corresponding digital code in the first digital codes, and the first signal is a signal, which is processed by the first converter circuitry, of the input signal and a previous stage residue signal. The calibration circuitry combines the first digital codes to output a second digital code, detects whether the quantization is completed to generate first and second valid signals, and determines whether to set the second digital code to be a first predetermined digital code or a second predetermined digital code according to the first and the second valid signals. The second valid signal is a delay signal of the first valid signal.

An analog-to-digital converting circuit includes: an analog-to-digital converter suitable for performing an analog-to-digital conversion on pixel signals of a plurality of pixels provided in a pixel array; a ramp signal generator suitable for providing a ramp signal to the analog-to-digital converter; and an auto-zero controller suitable for providing a reference voltage to the analog-to-digital converter to perform an auto-zeroing operation by using a row pixel for which a readout operation is performed by the analog-to-digital converter.

A photoelectric conversion device includes: pixels forming columns and each configured to output a pixel signal; and comparator units provided to respective columns and each configured to receive the pixel signal from the pixels on a corresponding column and the reference signal. Each comparator unit includes a comparator having a first input node that receives the pixel signal and a second input node that receives the reference signal, a first capacitor that connects a reference signal line and the second input node, a second capacitor whose one electrode is connected to the second input node, and a select unit that connects the other electrode of the second capacitor to either the reference signal line or a reference voltage line. The other electrode of the second capacitor is connected to the reference signal line during first mode AD conversion and connected to the reference voltage line during second mode AD conversion.

A method (100) for characterising processing differences between analog channels, the method comprising injecting (102) three analog signals into a first analog channel and a second analog channel, digitising (104) these signals so as to obtain digital signals x.sub.k, x.sub.l and y.sub.l having N samples, estimating (106) parameters γ.sub.k,l and δ.sub.k,l from the digital signals, where γ.sub.k,l is a ratio between an amplitude of the first analog signal at the output of the first analog channel and an amplitude of the second analog signal at the output of the second analog channel, and where δ.sub.k,l is a difference between a phase shift induced by the first analog channel in the first analog signal and a phase shift induced by the second analog channel in the second analog signal, the estimation comprising the application of a least squares method in order to determine values of the parameters γ.sub.k,l and δ.sub.k,l minimising the following quantity:

[00001]$\underset{n=1}{\overset{N}{.Math.}}{\left(x_k\left(n\right)-{\gamma }_{k,l}\left(\cos \left({\delta }_{k,l}\right)x_l\left(n\right)-\sin \left({\delta }_{k,l}\right)y_l\left(n\right)\right)\right)}^2$