【摘要】 设计了一种应用于 18 位 20 MS/s 流水线模数转换器 （Analog-to-Digital Converter, ADC） 的参考电压电路，电路采用源级推挽输出与电压负反馈结构的输出缓冲器，该输出缓冲器具有输出阻抗小、驱动能力高的特点。整体 ADC 电路采用 180 nm 1P6M 5 V CMOS 工艺实现，尺寸为 2.50 mm×5.00 mm，其中，参考电压电路尺寸为 0.20 mm×1.05 mm。仿真结果表明，参考电压电路中带隙基准电压在-40～90 ℃内温度系数为 5.526×10^-6/℃，应用所设计的参考电压电路，整体 ADC 在 20 MHz 采样频率下输入 859.375 k Hz 信号，有效位数 （Effective Number of Bits, ENOB） 为 16.88 bit，信噪比（Signal to Noise Ratio, SNR） 为 103.41 d B，无杂散动态范围 （Spurious Free Dynamic Range, SFDR） 为110.69 d B。更多还原

【Abstract】 A reference circuit based on output buffer with source stage push-pull output and voltage negative feedback structure is designed for an 18 bit 20 MS/s pipelined analog-to-digital converter （ADC）. The output buffer has the characteristics of small output impedance and high driving ability. The overall ADC circuit is fabricated by 180 nm 1P6M 5 V CMOS process, with the size of 2.50 mm ×5.00 mm, of which the reference circuit size is 0.20 mm×1.05 mm. The simulation results show that the temperature coefficient of the bandgap reference voltage is 5.526 ×10^-6/℃ at -40-90 ℃ . Under the application of the designed reference circuit, the overall ADC has an effective number of bits （ENOB） of 16.88 bit, a signal to noise ratio （SNR） of 103.41 d B and a spurious free dynamic range （SFDR） of 110.69 d B at 20 MHz sampling frequency and 859.375 k Hz inpu signal.更多还原