Abstract:
This paper proposes the design of a high-performance DC-DC converter used for the AM-OLED driver and controller system.The converter can output both the positive and negative voltages at the same time.In the error amplifier,feedback resistor is used to enlarge the dynamic range and so as to reduce the output ripple,and the low voltage isolation circuit is also introduced to improve the system start speed.In the comparator,the rail-to-rail differential input stage is used to improve the dynamic response speed and so as to reduce the output ripple.In the PWM driver circuit,the low-power driving circuit is used to improve the conversion efficiency.The circuits are designed in 0.16μm HV CMOS process.The Spice simulation results show that,when the input voltage is changed from 2.5V to 4.5V and the operating frequency is 1.5 M Hz,the positive output voltage is regulated to 4.6V and the negative output voltage can be changed from-2.4~-6.4V by adjusting the feedback resistors;furthermore the output ripples are less than 25 mV,the maximum load current can be 250mA,and the conversion efficiency is better than 85%,these performances are satisfied with the requirements of the AM-OLED driver and controller system.