The present invention relates to the field of programmable integrated circuits and in particular, to techniques and circuitry for implementing digital-to-analog converters (DACS) and analog-to-digital converters (ADCs) in a programmable logic.
Integrated circuits are important building blocks of the modern age. Technology continues to evolve and integrated circuits continue to provide improved functionality. As integrated circuits improve, so do the electronics systems that are built using integrated circuits. There are many types of integrated circuit such as memories, microprocessors, application specific integrated circuits (ASICs), and programmable logic. Programmable logic integrated circuits such as PALs, PLDs, FPGAs, LCAs, and others are becoming more complex and continually evolving to provide more user-programmable features on a single integrated circuit. Modern programmable logic integrated circuits incorporate programmable logic including logic gates, products terms, or look-up tables. Programmable logic integrated circuits also included embedded user-programmable memory or RAM.
Despite the success of programmable logic, there is a continuing desire to provide greater functionality in a programmable logic integrated circuit, but at the same time, provide greater performance. Desired functionalities include digital-to-analog and analog-to-digital conversion. Analog interfaces are needed especially as communications interfaces to, for example, 3G and 4G wireless, cable modems, Intelsat, and OFDM. A typical bandwidth for OFDM is 5 to 10 megahertz, cable modem is 5 megahertz, and 2.5 G–3 G–4 G is 3 to 5 megahertz. The typical desired resolutions are 6 to 10 bits. Also some multimedia applications need analog interfaces.
Therefore, there is a need to provide techniques and circuitry for implementing digital-to-analog and analog-to-digital conversion in programmable logic.