고출력전압 가변형 듀얼모드 DC-DC 벅-부스트 변환기 설계

In this paper, we design a dual-mode DC-DC buck-boost converter with variable output of -1.4V ∼ -5V. The BCDMOS process is adopted for high output voltage, and a SFM/PWM dual mode is used to enhance power efficiency. Also DC output voltage can be changed by controlling on/off duty ratio of power switching transistor with external control inputs. Simulation results with Spectre show that the output voltage varies with -1.4 ∼ -5V, and power efficiency has 87.5 ∼ 90.2% for the load current up to 250mA.