Dynamic characteristics of dc-dc converter with novel digital peak-current detector

The purpose of this paper is to present a novel digital peak-current detector and the dynamic characteristics of the current mode dc-dc converter using proposed one. The proposed circuit is able to detect the peak point of the switch/reactor current in real time only by comparing two pulse trains. The circuit principle is very simple. The peak point of the switch/reactor current is realized using the combination of the voltage controlled oscillator (VCO) using as the V-F signal converter, the programmable delay circuit and a few flip-flops. As a simulation results, the main switch is turned off when the peak switch current is detected. Additionally, it is shown that the proposed digital peak switch current detector provides the good transient responses of 100kHz digitally controlled dc-dc converter. As a result, it is seen that the proposed method has no overshoot of the output voltage and the convergence time that the output voltage is settled to steady-state is only 124μs. This result is approximately 83% smaller than the conventional voltage mode digital control dc-dc converter.