Abstract: A current measurement circuit may include unbuffered inputs, and the current may be sampled directly from the input pins. The input current created from each sample may be cancelled by injecting opposite charge on the subsequent sample. This direct sampling from the pins increases the common mode input range of the sense path without having to build high linearity rail-to-rail input buffers, hence lowering cost and power consumption of the current measurement path. It also allows for high-impedance input sampling. The measurement circuit may include multiple sampling stages, with a first sampling stage implemented as a switched-capacitor based circuit. A compensator circuit coupled in a feedback loop from the output of the first sampling stage to the input pins may be operated to provide the equivalent charge back to the input pins every cycle to cancel the input current required to charge the sampling capacitors of the first sampling stage.

Abstract: An adjustable current-synthesizer may generate synthesized current representative of an actual current, according to a model of a circuit that produces the actual current. The current synthesizer may under-sample a current sense signal derived from the actual current to obtain a few samples of the actual current, which are then used to adjust the synthesized current, thereby ensuring accuracy of the synthesized current. Sample values of the actual current are compared with corresponding generated values of the synthesized current to obtain offset values. In order to maintain monotonicity in the synthesizer results, the offset values are used to make adjustments to the slope of the synthesized current. The slope of the synthesized current may also be adjusted according to the slope of the actual current. Sub-Nyquist sampling of the actual current may be performed on the down-slope, with up-slope adjustments made based on the offset adjustment and down-slope adjustment.

Abstract: An adjustable current-synthesizer may generate synthesized current representative of an actual current, according to a model of a circuit that produces the actual current. The current synthesizer may under-sample a current sense signal derived from the actual current to obtain a few samples of the actual current, which are then used to adjust the synthesized current, thereby ensuring accuracy of the synthesized current. Sample values of the actual current are compared with corresponding generated values of the synthesized current to obtain offset values. In order to maintain monotonicity in the synthesizer results, the offset values are used to make adjustments to the slope of the synthesized current. The slope of the synthesized current may also be adjusted according to the slope of the actual current. Sub-Nyquist sampling of the actual current may be performed on the down-slope, with up-slope adjustments made based on the offset adjustment and down-slope adjustment.

Abstract: An adjustable current-synthesizer may generate synthesized current representative of an actual current, according to a model of a circuit that produces the actual current. The current synthesizer may under-sample a current sense signal derived from the actual current to obtain a few samples of the actual current, which are then used to adjust the synthesized current, thereby ensuring accuracy of the synthesized current. Sample values of the actual current are compared with corresponding generated values of the synthesized current to obtain offset values. In order to maintain monotonicity in the synthesizer results, the offset values are used to make adjustments to the slope of the synthesized current. The slope of the synthesized current may also be adjusted according to the slope of the actual current. Sub-Nyquist sampling of the actual current may be performed on the down-slope, with up-slope adjustments made based on the offset adjustment and down-slope adjustment.

Abstract: An adjustable current-synthesizer may generate synthesized current representative of an actual current, according to a model of a circuit that produces the actual current. The current synthesizer may under-sample a current sense signal derived from the actual current to obtain a few samples of the actual current, which are then used to adjust the synthesized current, thereby ensuring accuracy of the synthesized current. Sample values of the actual current are compared with corresponding generated values of the synthesized current to obtain offset values. In order to maintain monotonicity in the synthesizer results, the offset values are used to make adjustments to the slope of the synthesized current. The slope of the synthesized current may also be adjusted according to the slope of the actual current. Sub-Nyquist sampling of the actual current may be performed on the down-slope, with up-slope adjustments made based on the offset adjustment and down-slope adjustment.

Abstract: A current measurement circuit may include unbuffered inputs, and the current may be sampled directly from the input pins. The input current created from each sample may be cancelled by injecting opposite charge on the subsequent sample. This direct sampling from the pins increases the common mode input range of the sense path without having to build high linearity rail-to-rail input buffers, hence lowering cost and power consumption of the current measurement path. It also allows for high-impedance input sampling. The measurement circuit may include multiple sampling stages, with a first sampling stage implemented as a switched-capacitor based circuit. A compensator circuit coupled in a feedback loop from the output of the first sampling stage to the input pins may be operated to provide the equivalent charge back to the input pins every cycle to cancel the input current required to charge the sampling capacitors of the first sampling stage.