Over 10 million scientific documents at your fingertips. Other ADC strategies merely “capture” the analog signal level at a single point in time every cycle. Single-Slope ADC Architecture The simplest form of an integrating ADC uses a single-slope architecture (Figures 1a and 1b). The ADC’s real-time calibration scheme was proven to greatly improve the converter’s linearity and permit flexible segment setup for a wide range of possible imaging applications. Single-Slope ADC Architecture The simplest form of an integrating ADC uses a single-slope architecture (Figures 1a and 1b). An alternative A/D conversion technique uses the single-slope A/D converter. The sampling rate is determined by the user’s configuration of the clock sources and is limited to a maximum of 8.8 ksps. Abstract This paper presents a low noise CMOS image sensor (CIS) using 10/12 bit configurable column-parallel single slope ADCs (SS-ADCs) and digital correlated multiple sampling (CMS). The amount of time it takes for the spring to unwind at that fixed rate will be directly proportional to the speed at which it was wound (input signal magnitude) during the fixed-time portion of the cycle. The accurate correspondence of this ADC\’s output with its input is dependent on the voltage slope of the integrator being matched to the counting rate of the counter (the clock frequency). The time it takes for the integrator to trip the comparator is proportional to the unknown voltage (TINT/VIN). Thus, shaft speed is our “input signal” to be measured by this device. Here, an unknown input voltage is integrated and the value compared against a known reference value. It just shows an analog input, and its equivalent digital output. Thus, the clock speed error would cancel itself out and the digital output would be exactly what it should be. *H Page 2 of 16 Functional Description The ADC8 User Module implements a Single Slope A/D Converter that generates an 8-bit, full scale output (0 to 255 count range). Based Single Slope ADC For CMOS Image Sensor Column Readout @inproceedings{Guo2011BasedSS, title={Based Single Slope ADC For CMOS Image Sensor Column Readout}, author={Jia Guo}, year={2011} } Jia Guo; Published 2011; ACKNOWLEDGMENTS Since I left my country to study abroad, two years almost passed. Here, an unknown input voltage is integrated and the value is compared against a known reference value. This places the spring in a certain amount of tension proportional to the shaft speed: a greater shaft speed corresponds to a faster rate of winding. and a greater amount of spring tension accumulated over that period of time. Cite as. The time it takes for the sawtooth waveform to exceed the input signal voltage level is measured by means of a digital counter clocked with a precise-frequency square wave (usually from a crystal oscillator). For each ADC channel, the sub-range in which the voltage of the input signal falls is determined, and the corresponding ramp signal is selected … Single-Slope ADC Architecture The simplest form of an integrating ADC uses a single-slope architecture (Figures 1aand 1b). In one direction of ramping, the integrator is driven by the positive analog input signal (producing a negative, variable rate of output voltage change, or output slope) for a fixed amount of time, as measured by a counter with a precision frequency clock. In single-slope integrating ADC on op-amp based circuit, called an integrator to generate a saw tooth wave form is used, instead of the use of a DAC with a ramped output. Hence it is called a s dual slope A to D converter. Instead of using a DAC with a ramped output, we use an op-amp circuit called an integrator to generate a sawtooth waveform which is then compared against the analog input by a comparator. The simple, single-slope run-down is slow. In reality, a latching circuit timed with the clock signal would most likely have to be connected to the IGFET gate to ensure full discharge of the capacitor when the comparator\’s output goes high. In the dual-slope converter, an integrator circuit is driven positive and negative in alternating cycles to ramp down and then up, rather than being reset to 0 volts at the end of every cycle. The first comparator outputs a compared signal by receiving and comparing an input signal having a constant level with a ramp signal, the second comparator has a hysteresis property having an input terminal connected to an output terminal of the first … Want to see the step-by-step answer? The proposed EQ based single-slope ADC is designed in standard 130 nm CMOS process with 3.3 V supply voltage. So far, we\’ve only been able to escape the sheer volume of components in the flash converter by using a DAC as part of our ADC circuitry. 1. Here, an unknown input voltage is integrated and the value compared against a known reference value. Check out a sample Q&A here. A single slope ADC using a hysteresis property includes a first comparator, a second comparator, and a code generating unit. The ADC … A new integrating ADC architecture called single-slope look-ahead ramp (SSLAR) ADC is introduced in this paper. The gain-adaptive function is realized with the proposed switched-capacitor based gain control structure in which only minor changes from the traditional single-slope ADC are required. Not affiliated We'll assume you're ok with this, but you can opt-out if you wish. It is shown that SSLAR ADC reduces power consumption while achieving an increased frame rate. An answer to this calibration drift dilemma is found in a design variation called the dual-slope converter. This work adopts an ultralow power single slope ADC scheme as shown in Figure 6.Two main input referred noise sources of the single slope ADC include the KT/C noise introduced by capacitor Cos during reset phase (S1) and the random noise of inverter transistors. This website uses cookies to improve your experience. The only good thing to say about this circuit is that it avoids the use of a DAC, which reduces circuit complexity. Here, an unknown input voltage is integrated and the value compared against a known reference value. It is possible to avoid using a DAC if we substitute an analog ramping circuit and a digital counter with precise timing. Not logged in A dual-slope ADC (DS-ADC) integrates an unknown input voltage (V IN) for a fixed amount of time (T INT), then "de-integrates" (T DEINT) using a known reference voltage (V REF) for a variable amount of time. 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