Single-channel high-speed high-precision SAR ADC circuit

Abstract

The invention relates to a single-channel high-speed high-precision SAR ADC circuit, which comprises a bootstrap switch module, a capacitor array module, a comparator module, a latch module and an SARlogic control module, and is characterized in that the bootstrap switch module is used for controlling the transmission of a VIN input signal and a VIP input signal; the capacitor array module is used for sampling the VIN input signal and the VIP input signal to the capacitor array module according to a sampling signal when the bootstrap switch module is switched on; the comparator module is usedfor comparing the voltage of the VIN sampling signal with the voltage of the VIP sampling signal to obtain a VIN output signal and a VIP output signal, and obtaining judgment results; the latch module is used for temporarily latching and uniformly outputting the plurality of judgment results; and the SAR logic control module is used for generating a switch switching scheme of the capacitor arraymodule according to the plurality of judgment results. According to the circuit structure, the voltage establishing time of a high-weight capacitor is effectively reduced, the establishing precision is ensured, and the data conversion rate of the SAR ADC is improved.

Description

technical field [0001] The invention relates to the field of analog-to-digital conversion circuits, in particular to a single-channel high-speed and high-precision SAR ADC circuit. Background technique [0002] High-speed ADC (Analog-to-digital Converter, analog-to-digital converter) is the core part of the data acquisition system, and it is also an important factor affecting the accuracy and speed of the data acquisition system. Compared with other types of analog-to-digital converters, SAR (Successive Approximation Register, successive approximation analog-to-digital converter) ADC has medium speed (below 5MS / s), medium precision (8-16 bits), low power consumption and low The comprehensive advantages of cost and the proposal of various high-speed structures in recent years have made SAR ADC have a great development in the high-speed field. [0003] Due to the quantization principle of SAR ADC successive approximation, for an N-bit SAR ADC, at least N comparison cycles are...

AI Technical Summary

Problems solved by technology

Moreover, the capacitance value of the high-weight bit in the DAC is the largest, and the voltage establishment time constant is also the largest, so it is difficult to guarantee the accuracy of the capacitance establishment of the high-weight bit within a limited comparison period.

Images