Abstract: An electronic device is provided such as an amplifier, for example, having improved gain and transconductance and low output impedance. The device includes a primary amplifier configured to carry an operating load. The primary amplifier includes an input for receiving an input signal, and an output for outputting an output signal, and operates having a variable output, as it carries an operational load. The device further includes a secondary amplifier configured to operate at a fixed operating condition, not burdened by carrying an operational load, and includes a secondary input configured to receive the input signal, wherein the secondary amplifier is configured to define the input voltage. The device is configured to detect a difference in operating current between the primary and secondary amplifiers, and to compensate for any operational load that may be applied to the primary amplifier during operation.

Abstract: A volume control device including a digitally adjustable resistor. The digitally adjustable resistor causes a volume transition to be made in a series of incremental steps of small magnitude resulting in a smooth transition between volume levels, and, hence, no incidental noise.

Abstract: A CMOS imager includes a CMOS image sensor comprising an array of photoreceptors, a memory storing a reference operating level for the array, and readout circuitry for obtaining, at n-bit resolution, a photoreceptor reset value from the photoreceptors in the array. In addition, the CMOS imager includes comparison circuitry that determines a difference between the reference operating level and the photoreceptor reset value as well as matching circuitry that matches the difference against bins in a bin allocation. In particular, the bin allocation spans a photoreceptor noise range with the bins forming a quantization of the noise range into correction levels. Each of the correction levels may be associated with an m-bit correction code, where m is typically much less than n. As a result, the amount of memory necessary to store the correction codes is far less than that required to store full resolution (i.e., n-bit) values.

Abstract: An improved segmented analog to digital converter is provided, configured with a novel method of compensating current flow in secondary or successive segmented elements. In operation, dual current devices initially load, then subsequently unload a cascade of resistor networks connected to the secondary or successive voltage segmenting elements, preventing the perturbation of precise operation of the primary or preceding elements. In contrast to conventional approaches, the improved converter obviates the need for a buffer or amplifier to isolate the secondary and successive voltage segmenting elements from the primary or preceding elements.

Abstract: A signal processor has a plurality of channels, each channel configured to receive an input signal stream, to reduce the signal to a direct current signal and to process the signal according to the stream signal. Each channel also has a plurality of low pass filters configured to filter in-phase and quadrature-phase modulator outputs with a first low pass filter and to filter a reference quadrature signals, and a gain control configured to re-modulate gain adjusted output signals with the filtered quadrature signals. The processor further includes an inverter to invert the in-phase filtered reference signal and means to multiply the quadrature gain adjusted output signal.

Abstract: A system and method are provided for compensating for output error in a sigma delta circuit. The system includes an input for receiving an input signal and an output configured to output a output signal. The system further includes a summation component configured to add a first error voltage value, which is derived from an output signal, to an incoming input signal, and a subtraction component configured to subtract a second error voltage value, where the second error voltage value is derived from the adding of a first error voltage value to an incoming input signal.

Abstract: A high quality DAC is provided for a lower cost (including the layout size of the circuit on an audio chip) of high end DACs. The DAC includes a first circuit configured to remove even harmonics from a sigma delta circuit, and a second circuit configured to remove odd harmonics.

Abstract: An electrical isolation barrier for use in a Data Access Arrangement uses a high frequency (HF) transformer 24 to provide isolation. An input signal, which may be analog or digital, is connected to a modulator. The analog output of the modulator is connected to the input of the HF transformer. The output of the HF transformer is connected to the input of a demodulator. Simple amplitude modulation can be used in the modulator to modulate the input signal to the frequency range of operation of the HF transformer. A simple low pass filter may be incorporated in the demodulator to remove harmonic distortion caused by the HF transformer. The output signal of the demodulator is substantially the same as input signal.

Abstract: A differential input flash analog-to-digital converter in which an array of comparators is connected to compare reference signals within a parabolic distribution of such signals generated by the application of a differential input signal across an impedance network. Preferably, the comparator array comprises at least two pluralities of comparators, the first plurality of comparators comparing pairs of reference nodes separated by a first step size, and the second plurality of comparators comparing pairs of reference nodes separated by a second step size. Even more preferably, the comparator array further comprises a third plurality of comparators comparing pairs of reference nodes separated by a third step size, but only where necessary to maximize the available comparison range of the converter. The flash converter according to the invention provides increased gain from input without accumulation of comparator input currents and without sacrificing the number of actual comparisons of reference signals.

Abstract: A sigma delta circuit is provided having a sigma delta modulator configured to operate according to a first clock signal and a quantizer connected to the sigma delta modulator, where the quantizer is configured to operate according to a second clock signal. In operation, if a small amplitude signal is received by the sigma delta circuit, the circuit is configured to operate at a fixed output frequency. When a large amplitude signal is received, the circuit is configured to adjust to a different frequency to accommodate the larger signal. The second clock signal may be a variable clock signal, where the quantizer operates according to a variable clock signal in order to adjust to different input signals.

Abstract: The invention is directed to a bi-quad filter circuit configured with sigma-delta devices that operate as binary rate multipliers (BRMs). Unlike conventional bi-quad filter circuits, the invention provides a bi-quad filter configured with a single-bit BRM. In another embodiment, the invention further provides a bi-quad filter configured with multiple-bit BRMs.

Abstract: An electronic device is provided such as an amplifier, for example, having improved gain and transconductance and low output impedance. The device includes a primary amplifier configured to carry an operating load. The primary amplifier includes an input for receiving an input signal, and an output for outputting an output signal, and operates having a variable output, as it carries an operational load. The device further includes a secondary amplifier configured to operate at a fixed operating condition, not burdened by carrying an operational load, and includes a secondary input configured to receive the input signal, wherein the secondary amplifier is configured to define the input voltage. The device is configured to detect a difference in operating current between the primary and secondary. amplifiers, and to compensate for any operational load that may be applied to the primary amplifier during operation.

Abstract: A device is provided having at least two capacitive elements configured to retain a charge, and an interconnection of active devices between the capacitive elements. The active devices are configured to operate upon a transient charge flow as a current when in operation. The charge flow is partitioned into at least two capacitors according to the input voltage difference acting as a controlling parameter.

Abstract: An apparatus for edge enhancement of a digital image provided as raw digital image data to an input terminal and for providing processed image data to an output terminal. An offset processing circuit is coupled to the input terminal and configured to receive the raw data and generate offset data. An interpolation circuit is coupled to the offset processing circuit and configured to receive the offset data and to provide interpolated data. A color processing circuit is coupled to the interpolation circuit and configured to process the interpolated data to generate color data. An edge enhancement circuit is coupled to the interpolation circuit and the color processing circuit and configured to enhance the edges of the image based on the interpolated data and the color data to generate enhanced data. A lookup table is coupled to the color processing circuit and the edge enhancement circuit and configured to lookup the color data and the enhanced data to generate lookup data.

Abstract: The invention provides a frequency locked loop and related method that enables the conversion of a signal frequency with improved stability. A frequency locked loop embodying the invention includes an input for receiving an input signal and an output for outputting an output signal having a different frequency than the input. A frequency detector is configured to receive the first factored input from the primary channel and the second factored input from the secondary channel, to calculate the difference between the first factored input and the second factored input and to produce an output based on the difference between the two factored inputs. A voltage controlled oscillator is configured to receive the output from the frequency detector, and to produce an output signal. The voltage controlled oscillator ultimately sets the output frequency based on the output of frequency detector.

Abstract: An analog-to-digital converter in which each of a plurality of comparators is, in a successive approximation manner, selectively enabled or disabled and the outputs from those comparators summed together to produce a digital signal therefrom. By weighting and mixing outputs of adjacent comparators in proportions calculated to provide an interpolated output of a virtual comparator between the actual comparators, many such virtual comparators can be created without the need for additional fixed hardware elements in the converter. By doing so, the converter is able to produce a digital output having n bits using only N actual hardware elements for comparing signals, where N<2n−1. Each of the plurality of comparators in the converter has an input for an enabling signal, which enabling signal can be manipulated to enable or disable individual comparators and to modify their outputs. A method for converting an analog input signal into a digital signal using such a converter.

Abstract: A sensor may be formed with a transistor comprising a gate that has both n-type and p-type regions to increase the gate work function. In combination with moving the p-type well such that the p-type well only partially dopes the channel of the transistor, the increased gate work function further increases the reset voltage level required to create the reset channel without having to use high doping levels in the critical regions of the sensor structure including the photo-detector and the reset transistor. The source of the reset transistor is partially beneath the n-type region of gate, while the transistor's drain is partially beneath the p-type region of the gate. The channel has a p-type well portion and a substrate portion. This construction of the sensor may eliminate the reset noise associated with the uncertainty of whether the charge left in the transistor's channel will flow back towards the photo-detector after the transistor has been turned off.

Abstract: The invention provides a method and apparatus for performing a voltage to current conversion. In particular, the invention provides a voltage to current converter configured to vary its transconductance (Gm). Such a converter is configured to receive a voltage input signal combined with a reference voltage signal to be converted to a current output. Optionally, the reference voltage signal may be provided by a parabolic impedance network that includes a bank of resistors and a plurality of corresponding current sources. Each current source corresponds to each node between two resistors, and may be varied in order to program changes in the comparator's Gm. Each resistor and corresponding current source is configured to create an individual reference voltage reference having a value that occurs in a parabolic manner in relation to other voltage references occurring across the impedance network.

Abstract: An imager includes an array of imager cells coupled to a multi-mode controller. The multi-mode controller includes circuitry that implements several modes of operation, including a high-light mode, a low-light mode, and a Snap mode. The high-light mode provides charge accumulation in a photoreceptor potential well, a readout potential well, and a sense node potential well. The low-light mode provides charge accumulation in the photoreceptor potential well constrained by an integration potential well. The Snap mode of operation simultaneously transfers accumulated charge for a set of the imager cells to their sense nodes. In addition, the multi-mode controller may select one of a plurality of V+ integration voltages for setting up a selected charge capacity in one of the imager cells. Thus, the V+ integration voltage may be increased to provide charge capacity to address increased light levels.

Abstract: An imager cell includes a photoreceptor, a sense node, and a pinned transfer gate. The pinned transfer gate is disposed to transfer charge between the photoreceptor and the sense node. The imager further includes a reset transistor disposed to reset the sense node, and an output amplifier coupled to the sense node. Control circuitry supplies a photoreceptor readout clock to the photoreceptor. The readout clock includes an integration period and a transfer period. During the integration period, the readout clock is at an integration voltage V+ which may be varied to setup a desired charge capacity in the photoreceptor. A thin gate structure or light aperture may be included to enhance blue light response of the photoreceptor. Thus, the imager cell provides improved noise performance, selective charge capacities, and improved blue light response beyond that of conventional imager cells.