Research And Design Of A Low Power Swift Power Distribution Switches

As the increasing and development of the popular products such as the MP3, mobile store disk, and flash so on in the electronic market, these trends facilitate the people's life and work. Meanwhile, these swift store devices count on bus-powered Universal series bus (USB). Power switch is a key part of the USB to supply the functions of efficiently managing power and descending the power cost. In that way, provide a fundamental method to prolong the usage of battery. A high-speed, stable, low power cost power switch is able to abroad apply in the portable equipments of power management and hot plug for playing key role.Compared the traditional power switch circuit, the chip designed in this thesis is featured with decreasing complexity and cost of system, improving applicable ability of products. Because of its low power design, power switch chips can be widely used on portable products such as mobile charger, slot of USB. Due to such advantages of power switch chip, it becomes a hot spot of our research.The project does lots of research on power distribution switch circuits, a kind of based Bi-CMOS process power switch chip is designed what can swift, efficiently and low power turn-off or turn on supply voltage, and forestall the reverse current flowing the switch. The chip with multiple functions use 5-Pin packing outline. This paper describes research background and development trends of power switch circuits firstly. Then, study the total system structure, and accordingly to its function, divided the system into five modules: EN enable circuits, ThermalDetection shut down circuits, ChargePump, CurrentLimit, periphery top circuits. Each module's structure is designed carefully and suggests relative principle and advantage about the circuits: simulations are described and analyzed in details. Layout design of the chip and system simulation is given finally.The chip has passed simulation and verification of EDA software such as Cadence,Hspice, layout design, project evaluation check, and sign off. From the sample's check report, all basic function is correct, and each performance reaches the anticipative Design guideline.