Digital-to-analog converter capable of optimizing power consumption and output signal-to-noise ratio

Abstract

The invention relates to a digital-to-analog converter capable of optimizing power consumption and output signal-to-noise ratio, belonging to the design field of mixed signal integrated circuits. The digital-to-analog converter comprises an interpolation filter, a 1-bit delta-sigma modulator, a class-D power amplifier, an analog low pass filter and a DLPF (Digital Low Pass Filter) coder, wherein the interpolation filter, the 1-bit delta-sigma modulator, the class-D power amplifier and the analog low pass filter are sequentially connected; and the DLPF coder is connected between the 1-bit delta-sigma modulator and the class-D power amplifier. The input multi-bit digital signals firstly finish the up-sampling through the interpolation filter and then finish the noise shaping through the 1-bit delta-sigma modulator, 1-bit codes output by the modulator are coded by the DLPF coder, 2-bit codes output by the DLPF coder control the switching operation of the class-D power amplifier, and finally, the unnecessary out-of-band noise is filtered out through the analog low pass filter, thereby realizing digital-to-analog conversion and power amplification. The invention can lower the switching operation frequency of the class-D power amplifier, thereby lowering the power consumption of a delta-sigma digital-to-analog converter; and the invention also can improve the signal-to-noise ratio of output signals.

Description

Technical field [0001] The invention belongs to the field of mixed-signal integrated circuit design, and particularly relates to a ΔΣ digital-to-analog converter for optimizing power consumption and output signal-to-noise ratio. Background technique [0002] The delta-sigma (Delta-Sigma) digital-to-analog converter transfers most of the conversion process to the digital domain. The complexity of the digital circuit is exchanged for the high requirements for the analog conversion circuit, which can achieve high-precision conversion without precise component matching, and cost Low and easy to integrate, it is widely used in high-quality digital audio signal processing, multimedia signal processing and other fields. Class D power amplifiers have the advantages of high efficiency, small size, light weight, and large output power, which can effectively reduce the requirements for power supply and heat dissipation, and become a better choice for portable equipment. Therefore, the ΔΣ d...

AI Technical Summary

Problems solved by technology

However, due to the up-sampling of the signal by the interpolation filter in the previous stage, the working clock frequency of the circuit is relatively high, and the high-speed 1-bit code stream and its inverse code stream modulated by the 1-bit ΔΣ modulator control Class D The rapid on-off of the power amplifier switch results in a relatively large power consumption of the circuit; in order to obtain an output signal with a higher signal-to-noise ratio, the high-speed 1-bit bit stream drives the Class-D power amplifier so that the design of the analog low-pass filter circuit in the subsequent stage is improved. Relatively high requirements, so there is room for improvement

Images