A14-bit-200MHZ Current-steering D/A Converter

Now, with the development of communication technology,3G technology,4G technology and5G technology have been widely researched. And all corresponding key module data converters for communications’ systems was putting forward into higher requirements. Therefore, a more accurate higher-speed data converters’ design becomes the current urgent needs to solve the problem. While current-steering DAC plays a very critical role in all data converters. It is a typical type of high-speed data converters. So designing a high performance current steering D/A converter is of far-reaching significance.This article is based on SMIC0.18um Standard CMOS1P6M process, designing a14-bit segmented current steering gear-based Digital-to-Analog Converter. Using5+4+5segmented structure, binary terms codes and decoding of thermometer codes used for input. Introductions of each key modules are very detailed and all of them are simulated successfully. The current source switch array size, the function and performance of clipping amplitude circuit, bandgap reference current source simulation, and layout are introduced in detail this paper. The current source using cascade structure to improve the output impedance, clipping amplitude circuit can reduce the glitch of switch gate, thermometer decoder and binary coding combined is used to eliminate the output waveform peak, the layout of current source and switch array, they use Q2random walk selection method to reduce the errors.Finally in the frequency of the0.9993MHz signal, the sampling frequency of200MHz SFDR simulation results is95dB, the post simulation result is more than93dB, the process of other kinds’ condition simulation performance is very well. In the test of board level circuit, the chip is working properly, the power supply voltage of3.3V,20mA with maximum current, power consumption is90mW, INL/DNL test results also have good performance.