Papers by Keyword: Bandgap Reference

Abstract: An integrated ramp generator is presented in this paper. For traditional implementations, the amplitude clamp is realized with zener diode to limit the output voltage to ±V_Z, while the zener diode is not available for standard CMOS process. The transmission gate is utilized to make the output voltage in the determined range. The reference voltage is provided by a bandgap voltage reference with temperature compensation, which guarantees the temperature stabilization of the frequency of the ramp generator. The ramp generator was fabricated in a commercial CMOS process. The frequency of 44kHz is achieved under the power supply of 3.5V, and the frequency variation of 41kH to 46kHz with the power supply of 3.3V to 5V.

Abstract: This paper presents a bandgap reference and an output-capacitorless LDO regulator with adaptive power transistors. The bandgap reference consists of a current reference circuit, a bipolar transistor and proportional-to-absolute-temperature (PTAT) voltage generators. The proposed LDO improves load transient and light load efficiency by permitting the regulator to transform itself between 2-stage and 3-stage topologies, depending on the load current condition. Cadence simulation with SMIC 0.18 μm process shows that the bandgap reference generates a reference voltage 569 mV and the quiescent current is only 0.23 μA, the proposed LDO generates an output voltage 1 V, the quiescent current is 0.88 μA (including bandgap reference) at no-load condition, the undershoot /overshoot voltage is 187 mV/152 mV and the settling time is 5 μs as load current suddenly changes from 0 to 100 mA, or vice versa.

Abstract: Bandgap voltage reference, to provide a temperature and power supply insensitive output voltage, is a very important module in the analog integrated circuits and mixed-signal integrated circuits. In this paper, a high performance CMOS bandgap with low-power consumption has been designed. It can get the PTAT (Proportional to absolute temperature) current, and then get the reference voltage. Based on 0.35μm CMOS process, using HSPICE 2008 software for circuit simulation, the results showed that , when the temperature changes from -40 to 80 °C, the proposed circuit’s reference voltage achieve to 1.2V, temperature coefficient is 3.09ppm/°C. Adopt a series of measures, like ESD protection circuit, in layout design. The ultimately design through the DRC and LVS verification, and the final layout size is 700μm * 560μm.

Abstract: This paper presents a design and analysis method of a bandgap reference circuit. The Bandgap design is realized through the 0.18um CMOS process. Simulation results show that the bandgap circuit outputs 1.239V in the typical operation condition. The variance rate of output voltage is 0.016mV/°C with the operating temperature varying from-60°C to 160°C. And it is 3.27mV/V with the power supply changes from 1.8V to 3.3V.

Abstract: A bandgap reference without passive components based on standard CMOS is proposed. Using an improved inverse-function technique without any curvature-compensated techniques, two reference voltages are got in different temperature ranges. One is 1.56V with a temperature coefficient of 9.2ppm/°C in the range [0, 14 °C at 3.3V supply voltage, and the other is 1.546V with 47ppm/°C in [-25, 15 °C at 3.3V. Its PSRR (power supply rejection ratio) is below-60dB at 10kHz, and it is quite suitable for integration in processing circuits of MEMS (micro-electro-mechanical systems) devices.

Abstract: The reference is an important part of the micro-gyroscope system. The precision and stability of the reference directly affect the precision of the micro-gyroscope. Unlike the traditional bandgap reference circuit, a circuit using a temperature-dependent resistor ratio generated by a highly-resistive poly resistor and a diffusion resistor in CMOS technology is proposed in this paper. The complexity of the circuit is greatly reduced. Implemented with the standard 0.5μm CMOS technology and 9V power supply voltage, in the range of -40~120°C, the temperature coefficient of the proposed bandgap voltage reference can achieve to about 1.6 ppm/°C. The PSRR of the circuit is -107dB.

Abstract: The reference is an important part in the accelerometer system. With the development of science and technology, the request of the performance of accelerometers is increasingly higher and the precision of reference directly affects the performance of accelerometers. Therefore, a reference voltage applicable to accelerometers is presented based on the analysis of basic principles of conventional bandgap reference (BGR) in this paper. A high-order curvature compensation technique, which uses a temperature dependent resistor ratio generated by a high poly resistor and a nwell resistor, effectively serves to reduce temperature coefficient of proposed reference voltage circuit and to a large extent improve its performance. To achieve a high power supply rejection ratio (PSRR) over a broad frequency range, a pre-regulator is introduced to remain the supply voltage of the core circuit of BGR relatively independent of the global supply voltage. The proposed circuitry is designed in standard 2.0μm CMOS process. The simulated result shows that the average temperature coefficient is less than 2ppm/°C in the temperature range from -40 to 120°C. The improvement on temperature coefficient (TC) is about 10 times reduction compared to the conventional approach. And the PSR at DC frequency and 1kHz achieves -107 and -71dB respectively at 9.0V supply voltage.

Abstract: This work demonstrates that a stable voltage reference with temperature, in the 25°C-300°C range is possible using SiC bipolar diodes. In a previous work, we have been demonstrated both theoretical and experimentally, the feasibility of SiC bandgap voltage reference using SiC Schottky diodes [1]. The present work completes the investigation on SiC bandgap reference by the using of SiC bipolar diodes. Simulated and experimental results for two different SiC devices: Schottky and bipolar diodes showed that the principles that govern the bandgap voltage references for Si are also valid for the SiC. A comparison between the output voltage levels of the two types of bandgap reference is also presented.