Design Of A Buck PWM DC-DC Power Management Chip

In recent years, with the rapid expansion of portable electronics market, the demand for power management chips is also increasing. Portable technique requires power management chip with low power consumption, small size and other characteristics. Pulse width modulation as a way of voltage transformation is widely used because of its high conversion efficiency, ease of implementation and other characteristics. This paper mainly studies the designing problem of current-mode PWM DC-DC controller chip.This paper has analyzed the peak current-mode PWM buck controller working principle and circuit structure, designed the chip inside the main function blocks that include bandgap reference, operational amplifier, oscillator, comparators, logical driver and protection circuit and presented the transistor-level circuits respectively. The function blocks has been simulated with the simulation Hspice software and the simulation results were given, thus the overall circuit design was completed. The simulation results show that the chip meets the design requirements which are simple structure of overall circuit, high output voltage accuracy, low power consumption, and small size with different working conditions. At the end of the paper, the designing program of the layout is presented as well.