提出一种用于DC/DC变换器的数字自适应电压定位(Adaptive Voltage Position,简称AVP)控制器,与一般的控制器相比,它能让变换器使用更小的输出电容,因此可有效降低成本。控制器用现场可编程门阵列(FieldProgrammable Gate Array,简称FPGA)实现。变换器的开关频率为1MHz,输入电压为12V,输出电压可调节范围为0.875～1.875V。当负载在0.2～10A之间突变时,输出电压的变化为40mV。实验结果证明了设计的正确性。
An improved switched-capacitor bandgap reference with a continuous output voltage of 1.26 V has been implemented with Chartered 0.35-μm 5-V CMOS process. The output offset voltage, induced by non-ideal characteristics of operational amplifier and bias current generator, is suppressed by the proposed sample-and-hold circuit and self-bias technique. Experimental results show that the proposed circuit operates properly under a supply voltage varying from 3 to 5 V. The measured temperature coefficient is 112 ppm/℃ and the power supply rejection ratio of output voltage without any filtering capacitor is -40 dB and -33 dB at 100 Hz and 10 MHz, respectively.
This paper presents a dual voltage-controlled-delay-line（VCDL） delay-lock-loop（DLL） based gate driver for a zero-voltage-switching（ZVS） DC-DC converter.Using the delay difference of two VCDLs for the dead time control,the dual VCDL DLL is able to implement ZVS control with high accuracy while keeping good linearity performance of the DLL and low power consumption.The design is implemented in the CSM 2P4M 0.35μm CMOS process.The measurement results indicate that an efficiency improvement of 2%-4%is achieved over the load current range from 100 to 600 mA at 4 MHz switching frequency with 3.3 V input and 1.3 V output voltage.
This paper presents a width controller,a dead time controller,a discontinuous current mode（DCM） controller and a frequency skipping modulation（FSM） controller for a high frequency high efficiency buck DC-DC converter. To improve the efficiency over a wide load range,especially at high switching frequency,the dead time controller and width controller are applied to enhance the high load efficiency,while the DCM controller and FSM controller are proposed to increase the light load efficiency.The proposed DC-DC converter controllers have been designed and fabricated in the Chartered 0.35μm CMOS process,and the measured results show that the efficiency of the buck DC-DC converter is above 80%over a wide load current range from 8 to 570 mA,and the peak efficiency is 86%at 10 MHz switching frequency.
