Two-stage resistor network and digital-to-analog converter based on two-stage resistor network

Abstract

A two-stage resistor network and a digital-to-analog converter based on a two-stage resistor network are disclosed. The two-stage resistor network comprises 2M cascaded first resistor modules, and a first connecting end of a first resistor in each first resistor module is connected with a first connecting end of the first resistor module, a second connecting end is connected with a second connecting end of the first resistor module through a first switch, and two ends of the first switch are respectively connected with reference voltage through a second switch and grounded through a third switch; the first resistor of the 2M-th first resistor module comprises 2L second resistors connected in series and 2L fourth switches connected between the second connecting ends and the output ends of the 2L second resistors respectively. The digital-to-analog converter divides a N-bit digital signal into a high M-bit digital signal and a low L-bit digital signal, N is equal to M+L, the high M-bit digital signal controls switches in the 2M first resistor modules after being decoded, and the low L-bit digital signal controls the 2L fourth switches after being decoded. Compared with a simple resistor string DAC, the invention has the advantages that the single characteristic of the DAC is inherited, and the number of switches is greatly reduced.

Description

technical field [0001] The invention belongs to the technical field of integrated circuits and analog circuits, and relates to a two-stage resistance network and a high-precision digital-to-analog converter based on the two-stage resistance network. Background technique [0002] The resistor network is an important part of the digital-to-analog converter (DAC), which has a great influence on the power consumption, area and precision of the digital-to-analog converter DAC. The existing high There are various architectures for precision DACs, such as resistor string architecture and R2R architecture, both of which are analog circuits using digital control logic. [0003] Such as figure 1 Shown is a DAC composed of a resistor network with a simple resistor string structure. The simple resistor string DAC has good monotonic characteristics, but it is not suitable for high-resolution DAC applications. From figure 1 It can be seen that for an N-bit resistor string DAC, there ar...

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Problems solved by technology

[0006] Aiming at the inadequacies of the above-mentioned traditional resistor string architecture and R2R architecture digital-to-analog converters that cannot achieve high precision and small area at the same time, the present invention proposes a two-stage resistor network, which greatly reduces the number of switches compared with the resistor network of the resistor string architecture. number, greatly reducing the area and layout workload; the digital-to-analog converter based on the two-stage resistor network design of the present invention has greatly inherited the monotonic characteristics of the simple resistor string DAC, and has the characteristics of high precision

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