摘要:
Various embodiments of an amplifier circuit are provided. In one embodiment, the amplifier circuit includes an input differential circuitry configured to convert a pair of input differential voltage signals to a pair of differential current signals. The amplifier circuit includes a cascode circuitry operable to mirror the pair of differential current signals received from the first output terminal and the second output terminal to an output terminal of the first cascode transistor and an output terminal of the second cascode transistor. The amplifier circuit includes a current control circuit operable to divert an amount of bias current to reduce a current through the cascode circuitry, to thereby reduce a load of the amplifier circuit, the reduction in the load of the amplifier circuit allowing a reduction in current through the input differential circuitry for maintaining a predetermined bandwidth of the amplifier circuit.
摘要:
Various embodiments of an amplifier circuit are provided. In one embodiment, the amplifier circuit includes an input differential circuitry configured to convert a pair of input differential voltage signals to a pair of differential current signals. The amplifier circuit includes a cascode circuitry operable to mirror the pair of differential current signals received from the first output terminal and the second output terminal to an output terminal of the first cascode transistor and an output terminal of the second cascode transistor. The amplifier circuit includes a current control circuit operable to divert an amount of bias current to reduce a current through the cascode circuitry, to thereby reduce a load of the amplifier circuit, the reduction in the load of the amplifier circuit allowing a reduction in current through the input differential circuitry for maintaining a predetermined bandwidth of the amplifier circuit.
摘要:
In pipeline analog-to-digital converters (ADCs) the third harmonic can degrade the performance of the ADC, and conventional circuits that attempt to cancel this third harmonic are oftentimes sensitive to process variation, temperature variation, and common mode variations. Here a correction circuit is provided that includes a compensator that adjusts control voltages for MOS capacitors to generally ensures that the difference between the gate-source voltages and threshold voltages of MOS capacitors is generally maintained across variations of process, temperature, and common mode.
摘要:
Traditionally, successive approximation register (SAR) analog-to-digital converters (ADCs) using binary search algorithms have consumed power by performing unnecessary switching of a capacitive digital-to-analog converter (CDAC) when a CDAC voltage is relatively close to a sampling analog input signal. Here, a SAR ADC is provided that reduces the number of switching events. To accomplish this, a multi-stage comparator is provided that generates multiple output signals for SAR logic. Based on these outputs, the SAR logic can more efficiently switch its CDAC using a ternary search algorithm to reduce power consumption and improve efficiency.
摘要:
A time-interleaved (TI) analog-to-digital converter (ADC) is provided. The TI ADC generally comprises a clock generator, two or more ADCs, adjustable delay elements, and an estimator. The clock generator generates clock signals. Each ADC is associated with at least one of the clock signals so as to sample an input signal that is generally wide-sense stationary at sampling instants, where correlation function exist between samples from a two or more of the ADCs that is a function of the time differences between associated sampling instants. The estimator is coupled to each of the adjustable delay elements and each of the ADCs so as to calculate the correlation function and adjust the adjustable delay elements to account for sampling mismatch between the ADCs based at least in part on the correlation function.
摘要翻译:提供了时间交织(TI)模数转换器(ADC)。 TI ADC通常包括时钟发生器,两个或更多个ADC,可调延迟元件和估计器。 时钟发生器产生时钟信号。 每个ADC与至少一个时钟信号相关联,以便在采样时刻对通常为宽静态的输入信号进行采样,其中相关函数存在于两个或更多个ADC之间的样本之间,该两个或更多个ADC是 相关抽样时间之间的时间差异。 估计器耦合到每个可调节延迟元件和每个ADC,以便计算相关函数,并且至少部分地基于相关函数来调整可调延迟元件以考虑ADC之间的采样失配。
摘要:
Parallel search circuit for a medical implant receiver. The circuit includes a radio frequency receiver that receives a first set of contents of a band of channels. The circuit also includes a processing circuit coupled to the radio frequency receiver to process in parallel a second set of contents of a plurality of channels of the band of channels and to detect a signal in the band of channels.
摘要:
Providing a substantially constant reference voltage to a component from a reference buffer connected by a path. The load that would be offered to the reference buffer in desired durations is estimated, and a dummy load is added to the path such that the aggregate load on the path is approximately constant. In case of the stages of an ADC, the sub-code generated by each stage during a sampling phase is used to estimate the load that would be offered, and the dummy load is added in the hold phase to keep the reference voltage constant in the hold phase, as desired.
摘要:
To apply a desired voltage at a node driving a load impedance, a voltage source providing the desired voltage is connected to the node. In addition, a current source supplying an amount of current that would be drawn by the impedance if the voltage source alone were connected across the impedance. As a result, the voltage source may be freed substantially from supplying current, which may be advantageously used in several situations. For example, the approach can be used to connect a voltage source directly to a high load without potentially requiring a buffer between the voltage source and the node. Alternatively, the approach can be used to apply the same desired voltage at each of multiple nodes connected in series using the same voltage source without being affected by the routing resistance generally present between each pair of the nodes.
摘要:
A low-noise output buffer for a digital signal is based on an analog amplifier having bandwidth greater than the switching rate of the digital logic signal. A converter circuit converts the digital logic signal to a ramp signal provided as an input to the analog amplifier. The ramp signal has a slope determined by a bias current and an input capacitance of the analog amplifier. The bias current is generated by a bias circuit such that the bias current varies as the input capacitance of the analog amplifier varies due to variations in the manufacturing process. Therefore, the slope of the ramp signal remains substantially constant despite the variations in the manufacturing process. In particular, the slope of the ramp signal is not undesirably steep even when the buffer is made by a worst-case “strong” process.
摘要:
A resistor (or a component with impedance that does not change) is provided across the output of an amplifier, which minimizes the changes in the amplification factor of an amplification circuit during operation.