Dynamic characteristics of the digitally controlled DC-DC converter

A comparison of steady‐state characteristics of buck‐type DC‐DC converter using DSP

“…ter. Here, the value of K I is selected to enable sufficient regulation from no load to the rated 2 A. K D is selected so that the system is stable [1]. The ∆e op−p value is nearly constant until some value when K I increases, but rapidly increases when that value is exceeded.…”

“…To improve the reliability of these power supplies, the addition of monitoring functions, the improvement in controllability, and reductions in the number of parts and adjustment locations in the control circuits are important. In this case, digital circuits are useful, and the presence of a digitally controlled DC-DC converter has been tried [1][2][3][4][5].…”

“…When a control circuit is constructed from a digital circuit, from the perspective of cost, a simpler system using a digital filter constructed from an ordinary A-D converter and a digital signal processor (DSP) is desired [1,5]. However, if this type of system is to be the subject of future research and development, first, the basic system constructed from the A-D converter and DSP must be studied.…”

“…P-I-D control, the minimum phase FIR filter [6], and the moving average [7] are considered as the control methods which use digital circuits. P-I-D control is widely used because of its simple design [1]. The minimum phase FIR filter features a smaller phase delay than the linear-phase FIR digital filter and a stable system, but the control constants are difficult to select.…”

http://sphinxsai.com/2018/ch_vol11_no4/1/(63-70)V11N04CT.pdf

“…control law that uses the high-pass-filtered inductor current and does not require knowledge of the reference current, which is load dependent for a desired output voltage. A complementary proportional-integral-differential (PID) controller to the PD-PBC has been designed for removing the steady state error owing to the parasitic resistance [8].Digitally controlled dc-dc converter the output voltageregulationis circumscribed of the within comparative narrow ranges ofthe input voltage and the load, and that increasing the integral gain of the digital control circuit to extendthe regulation range, will lead to deterioration in the dynamic characteristics ofthe converter [10].Derivative term of conventional PID controller injects noise in the feedback loop due to the series resistance and equivalent series inductance (ESR, ESL) of the output capacitor.…”