Research And Design Of Tri-mode DC-DC Converter With Dead-time Correction

With the development of electronic technology, switching power supply is not only used in telecommunications, aerospace, industrial and other fields, but also can be found in our daily life. Most portable electronic devices require better performance and smaller size, higher switching frequency which reduces conversion efficiency accordingly. However, switching power conversion efficiency is a very important performance parameters in practical applications. One of the major factors which affects the conversion efficiency is the dead time. So dead-time control method is very necessary.This paper compares several DC- DC converter topologies and disadvantages of control methods.Then analyzes the basic principles of the one-step dead-time control method and test the one-step dead-time correction with tri-mode DC- DC converter. The tri-mode non-inverting DC- DC converter with power transmission gate structure is used to determine the modules of dead-time correction. It includes the detection of body-diode conduction, the measurement of body-diode conduction and external circuit design based on specification of system. This dead-time correction algorithm can distinguish edges and correct two pair of rising edge and falling edge of input PWM gate driver signals at the same time, and realized the wide range of input and output of tri-mode Buck-boost DC-DC converter. After using existing MOSFET products for the verification circuit of dead-time correction method, and layout of the DC-DC buck-boost converter is designed and finished based on 0.18?m process.This paper presents a tri-mode buck-boost DC-DC converter with a power transmission gate and dead-time correction method. This converter accepts input voltage from 2.7V to 5.7V and generates output voltage from 0.3V to 6.8V with output current of up to 6A. The area of the designed chip was 1650?m × 2300?m. The converter can be achieved and fabricated by 0.18?m Dongbu Hitec technology. The correction algorithm can be realized and the converter functions well.