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Nowadays, constant current power supply is extensive used in modern industrial area. The traditional constant current power supply using a linear regulator with analog control method structure has many disadvantages of low conversion efficiency, weak anti-interference ability, low control accuracy, circuit complexity, low reliability, single function; especially it can not provide an intelligent human-machine interface. In this paper, a high-precision digital control current source is studied to explore the structure of a switch-mode, all-digital-controlled constant-current power supply. The constant-current power supply with this structure, compared to the traditional one, has high conversion efficiency, strong anti-interfere ability, high precision, simple circuit, high reliability and the advantages, especially with intelligent human-machine interface to meet the complexity of modern industrial control needs.First, a variety of traditional constant-current power supply’s structure and control methods were discussed, comparing there strengths and weaknesses. A switch-mode, full digital controlled constant current power structure is introduced, then it analyses this structure advantages and the study of constant-current power supply status.Next, it studied the principle of digital control constant current source, especially the analysis of digital control in the digital PWM, ADC, control and design of digital controller of the impact on system performance, pointed out things needed to pay attention to in practice.Under the theory, a detailed design of a BUCK topology, high-speed digital signal processor controlled constant-current power supply controller was given. It calculated the parameters of main part hardware, accurately modeled the system, and simulated it with MATLAB, given the detailed design and optimization of digital controller with direct design method.Finally, it designed the software of the system, implemented a sample, and tested it. The test results show that the switch-mode, full digital control of the constant current power supply is feasible with excellent performance.
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