Traditionally, spectrometers for space applications have been developed on field programmable gate arrays (FPGAs) with off-chip analog-to-digital converters (ADCs). However, with upcoming NASA missions to the outer planets and their moons, a spectrometer is required that is smaller, more power efficient, and more radiation tolerant than an FPGA, all of which can be satisfied by designing an application specific integrated circuit (ASIC). In addition, an ASIC has the added benefits of the ability to achieve higher spectral resolution and the capability to use an on-chip ADC, thus lessening the power needed to drive high speed chip interconnect. The focus of this work is on a spectrometer ASIC with spectral resolution of 183kHz and a bandwidth of 1.5GHz, twice that of its predecessor. Furthermore, these specifications are met on a chip with a footprint of less than 10mm2 and which consumes less than 1W of power. This represents a significant advantage over all previous work. The high bandwidth and low power were achieved primarily through the integration of a 3GS/s time-interleaved ADC onto the chip. This work also focuses on the tools and design flow that were used to design this mixed-signal ASIC spectrometer in 65nm technology.