Pipelined successive approximation analog-to-digital converter and conversion method

Abstract

The invention provides a pipelined successive approximation analog-to-digital converter and a conversion method. The pipelined successive approximation analog-to-digital converter comprises a first-stage successive approximation analog-to-digital conversion module, a second-stage successive approximation analog-to-digital conversion module and a digital code error correction logic module, whereinthe first-stage successive approximation analog-to-digital conversion module comprises a first capacitor array unit, an amplification unit, a latch comparison unit, a first register logic control unitand a control switch, and the amplification unit is multiplexed as a residual amplifier and a pre-amplifier of a comparator in the first-stage successive approximation analog-to-digital converter. Bymultiplexing the residual amplifier pre-amplifier, input offset voltage mismatch existing between the residual amplifier pre-amplifier and the residual amplifier pre-amplifier is completely eliminated, the input swing of the residual amplifier is stabilized, the linearity of the residual amplifier is improved, and the area of a chip is saved; and the gain error is obtained by multiplexing the second-stage successive approximation type analog-to-digital conversion module, so that the gain error of the residual amplifier is reduced, and the conversion accuracy of the whole pipelined successiveapproximation type analog-to-digital converter is improved.

Description

technical field [0001] The invention relates to the field of circuit design, in particular to a pipelined successive approximation analog-to-digital converter and a conversion method. Background technique [0002] Pipelined successive approximation analog-to-digital converters are widely used in medium-precision, medium-speed analogues because they have both the low power consumption of successive-approximation analog-to-digital converters and the high throughput and low noise of pipelined In digital converter application scenarios. [0003] The common two-stage pipeline successive approximation analog-to-digital converter 1 such as figure 1 As shown, after the first-stage successive approximation analog-to-digital converter 11, an open-loop operational amplifier is usually used as the residual amplifier 12, and the residual error voltage of the first-stage successive approximation analog-to-digital converter 11 is amplified and then sent to The second-stage successive app...

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Problems solved by technology

[0008] In view of the shortcomings of the prior art described above, the purpose of the present invention is to provide a pipelined successive approximation analog-to-digital converter and conversion method, which are used to solve the problem of gain mismatch, offset voltage mismatch and large chip area in the prior art. question

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