A16-bit1GSPS Current-Steering D/A Converter Design With Calibration

At present the systems for controlling information products and signal processingproducts are mostly digital circuits. And the core part is digital signal processor (DSP),microcontroller (MCU) and microprocessor (MPU). But in our real-life, all of thesignals are analog signals, while the communications of the electronic products arealso analog signals. So the study of D/A converters are very meaningful.This thesis uses the SMIC0.18μm1P6M standard CMOS process to achieve akind of16-bit1GSPS current-steering DAC with calibration, using6-5-5segmentationwith the high-six and the middle-five bits thermometer coding, while the low-five bitsare binary encoded. To increase the output impedance, the cascode structure is used incurrent source. Its layout is a kind of central symmetry map. The current source matrixis calibrated by fuse calibration program to ensure the matching of the current source.In order to improve the performance of analog switches, we design the low crosspointswitch driver circuit. This chip uses dual power supply with digital power1.8V, analogpower supply3.3V. Differential output structure is used, and the full-scale outputcurrent is10mA. The50resistor at the external converts the current to differentialvoltage.Base on the Cadence Spectre simulator environment and Virtuoso layout editor,designing and simulating the circuit and layout.The INL and DNL of this16bits1GSPS D/A converter are separate0.94LSB and0.75LSB, while the seting time is1.4ns; when the input signal is a sinusoid with3.4MHz, and the sampling clockfrequency is1GHz, the SFDR is87.39dB; when the input sinusoid signal is67.8MHzwith1GHz sampling clock frequency, the SFDR becomes69.43dB; the core chip areais about1.7mm×1.4mm.