A high-precision and low-cost digital sine wave generator

Abstract

The invention relates to a high-precision low-cost digital sine wave generating device, and belongs to the technical field of instruments and apparatuses. The device comprises a counting reset unit, a waveform calculation generating unit, a D / A converter and a low pass filter which are sequentially connected. The working process of the device includes the steps of S1, conducting initiating through the counting reset unit and the waveform calculation generating unit according to clock frequency and other parameters; S2, conducting calculation through the waveform calculation generating unit under the effect of the clock frequency by means of the bit width of N bit to calculate a sine wave sample value sequence point by point, resetting the numerical values in a register Y1 and a register Y2 through register Y1 and Y2 renewing modules when the counting reset unit reaches a preset counting value, and restarting counting; S3, intercepting a high M bit result through a waveform counting unit to be output to the D / A converter, and converting signals into analog signals through the D / A converter to be output through the low pass filter. Sine waves are obtained through a trigonometric function calculation mode, and the stray of a traditional DDS structure caused by ROM limited capacity and phase accumulator introduction is eliminated.

Description

technical field [0001] The invention belongs to the fields of communication and instruments, and relates to a high-precision and low-cost digital sine wave generator. Background technique [0002] Frequency synthesis technology originated in the 1930s and has gone through three generations. The first generation of direct frequency synthesis, using one or more different crystal oscillators as the reference signal source, using coherent or non-coherent technology, the reference frequency is added, subtracted, multiplied and divided to directly generate the output frequency; the second generation of phase-locked Type frequency synthesizer, a large number of harmonics or combined frequencies are generated through harmonic generator mixing and frequency division, and then the phase-locked loop locks the working frequency of the voltage-controlled oscillator on a certain harmonic or combined frequency; the third The first-generation Direct Digital Synthesis (DDS) technology emerg...

AI Technical Summary

Problems solved by technology

Due to the limitation of ROM capacity, the high bit of the output of the phase accumulator is used to address the ROM, resulting in phase truncation errors and spurious

[0010] 2. Amplitude quantization error

The data bit width of ROM is limited, which causes amplitude quantization error

[0011] 3. ROM limits the rate, power consumption and implementation cost of DDS

[0012] 4. The improved algorithm increases additional control and calculation consumption. Although there are many solutions for compressing ROM and optimizing strays, the complexity of algorithm and engineering implementation is relatively high

Images