應用於單電池模組系統之隨著負載控制且可操作於1伏輸入電壓之單電感雙輸出直流直流轉換器

Abstract

本論文提出應用於單電池模組系統之隨著負載控制且可操作於1伏輸入電壓之單電感雙輸出直流直流轉換器。經由本論文提出之隨著負載控制機制(ALTC)再配合上最少的開關及最佳的電流路徑選擇，能讓儲存在電感裡的能量隨著真實負載狀況做調整，防止過多的電荷儲存在電感裡，因此可降低輸出端互穩壓(cross regulation)的效應。此外，新提出的自偏壓電流源(SBCS)及電流模式的環型振盪器能產生極佳的系統時脈週期，取代傳統的環型振盪器。藉由所提出的電流模式環型振盪器能工作於轉換器啟動與穩態狀態，能減化轉換器在啟動時的設計，防止過高的切換頻率產生造成能量的消耗及縮小晶片的面積。本論文提出的轉換器使用TSMC 0.25μm 2.5V/5V製程來實現驗證晶片的設計。驗證晶片的實驗結果轉換效率最高92%，互穩壓效應小於10mV。

In this paper, a sub-1V input single-inductor dual-output (SIDO) DC-DC converter with an adaptive load-tracking control (ALTC) technology is proposed for single-cell-powered portable devices. Through the minimized number of switch and the optimum current sequence, the ALTC technique adaptively and accurately adjusts storage energy in form of inductor current according to the actual load condition without wasting surplus charge and increasing cross-regulation. Moreover, a current-mode ring oscillator with a self-bias current source (SBCS) circuit is proposed to replace the conventional startup ring oscillator to produce a nearly constant system clock. Owing to the proposed current-mode ring oscillator operates in the startup process and steady-state of SIDO DC-DC converter, a simplified design efficiently addresses high switching frequency losses at startup process and reduces chip area and power consumption. The proposed sub-1V input SIDO DC-DC converter was fabricated by TSMC 0.25 μm 2.5 V/5 V BCD process and the experimental results show a high efficiency of 92 % and a good cross-cross regulation smaller than 10 mV.