The present disclosure provides a detailed description of techniques for implementing a low power buffer with dynamic gain control. More specifically, some embodiments of the present disclosure are directed to a buffer having a gain boost configuration and a current shunt circuit to control the gain of a respective gain boosting transistor of the gain boost configuration. The current shunt circuit and resulting gain are dynamically controlled by a gain control signal such that the buffer gain can be adjusted to within an acceptable range of the target gain for the current operating and device mismatch conditions. In one or more embodiments, the gain boost configuration with dynamic gain control can be deployed in a full differential implementation. Both analog and digital dynamic calibration and control techniques can be used to provide the gain control signals to multiple current shunt circuits and multiple buffers.

Methods of generating a gradient waveform, gradient waveform generators and magnetic resonance imaging systems are provided. In one aspect, a first digital value is obtained by quantizing and coding spatial position information of a voxel of a subject according to the number of preset quantization bits, wherein the number of the quantization bits are more than the number of allowed input bits for a DAC; a second digital value is determined to be inputted into the DAC according to the first digital value and the number of the allowed input bits for the DAC; a quantization error is determined according to the first digital value and the second digital value; an error accumulating value is updated by accumulating the quantization error to the error accumulation value; the second digital value corrected according to the error accumulation value; and the corrected second digital value is inputted into the DAC.

Systems and methods are provided for adaptive configuration and control of digital-to-analog converters (DACs). Performance of a plurality of conversion elements in a digital-to-analog converter (DAC) may be assessed based on particular input conditions associated with a digital input to the DAC, and the DAC may be configured based on the assessing of performance. Each conversion element of the plurality of conversion elements handles a particular bit in the digital input. The configuring may comprise selecting a subset of the plurality of conversion elements, and setting only the subset of the plurality of conversion elements to apply a particular type of operations. The particular type of operations pertains to applying digital-to-analog conversions via the DAC, and the particular type of operations relates to or affects performance. The particular input conditions may comprise signal backoff.

An Interleaved Radio Frequency Digital-to-Analog Converter (RF DAC) suitable for use in cellular base stations and optimized to give both a wide RF tuning range and a wide RF bandwidth is disclosed. The RF DAC uses two levels of interleaving, the first providing a direct conversion path from Base Band (BB) to RF, and the second providing a variable interleaving factor through the use of summation to optimize the output bandwidth as a function of the RF center frequency. Digital Interpolation, including an arbitrary sample rate conversion filter, allows the RF DAC to operate from a wide range of possible BB sample rates and the DAC sample rate is a fixed ratio of the RF center frequency. As a result, the spurious outputs from the RF DAC are in known locations that are relatively easy to filter out, minimizing the frequency planning tasks required for a complete RF system design.

An apparatus for compensating for nonlinearities in a DAC caused by variabilities of a power supply. The apparatus may include a power supply, a processing component, and a front-end circuit. The power supply may generate power, where the power includes variabilities in a power. The processing component may generate a digital signal. The front-end circuit may be operatively coupled to the power supply and the processing component. The front-end circuit may receive the power from the power supply, identify the nonlinearities in the power, receive the digital signal from the processing component, and adjust the digital signal for the nonlinearities to obtain an input signal to send to a digital to analog converter (DAC).

An apparatus for compensating for nonlinearities in a DAC caused by variabilities of a power supply. The apparatus may include a power supply, a processing component, and a front-end circuit. The power supply may generate power, where the power includes variabilities in a power. The processing component may generate a digital signal. The front-end circuit may be operatively coupled to the power supply and the processing component. The front-end circuit may receive the power from the power supply, identify the nonlinearities in the power, receive the digital signal from the processing component, and adjust the digital signal for the nonlinearities to obtain an input signal to send to a digital to analog converter (DAC).

Split cascade circuits include multiple cascade paths coupled between voltage supply rails. Each cascade path includes a pair of controllable switches. A feedback path is provided for at least one of the cascade circuit paths. An active load circuit may also have a split cascade structure. Multiple-stage circuits, for implementation in Trans-Impedance Amplifiers (TIAs) or analog Receive Front-End modules (RXFEs), for example, include multiple stages of split cascade circuits.

An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate a divided clock signal and a control signal in response to (i) an input clock signal and (ii) a configuration signal. The second circuit may be configured to generate an output clock signal in response to (i) the control signal and (ii) the divided clock signal. The second circuit may add a delay to one or more edges of the output clock signal by engaging one or more of a plurality of capacitances. A number of the capacitances engaged may be selected to reduce jitter on the output clock signal. The capacitances may be used each cycle to calibrate the output clock signal.

An apparatus comprising a first circuit and a second circuit. The first circuit may be configured to generate a divided clock signal and a control signal in response to (i) an input clock signal and (ii) a configuration signal. The second circuit may be configured to generate an output clock signal in response to (i) the control signal and (ii) the divided clock signal. The second circuit may add a delay to one or more edges of the output clock signal by engaging one or more of a plurality of capacitances. A number of the capacitances engaged may be selected to reduce jitter on the output clock signal. The capacitances may be used each cycle to calibrate the output clock signal.

An apparatus comprised of a cascaded series of optical modulators addressed by a multi-bit digital word with each optical modulator in the cascaded series being responsive to a single bit in the multi-bit digital word and wherein each of the optical modulators in the cascaded series of optical modulators doubling in effective optical length as a bit index of the bit of the multi-bit digital word to which it is responsive increases by a bit index value equal to one. The apparatus may be used with a prior art analog optical modulator and an associated ADC, having a fixed bit width, to extend the number of bits beyond the fixed bit width that the ADC and analog optical modulator prior art combination can otherwise operate.