Being an indispensable technique in the standard laboratory, Nuclear Magnetic Resonance (NMR) is a versatile method to non-invasively observe the atomic and molecular information of the samples containing non-zero spin nuclei. Yet, the bulky and costly hardware for NMR impedes their broad distributions outside the laboratory for on-demand and on-line usage. In recent years, with the advance in microelectronics, NMR systems equipped with customized silicon chips emerged to achieve system miniaturization with performance enhancement, and pioneer novel applications that were not feasible before using discrete NMR electronics. This article overviews the hardware for NMR from the system-level perspective, and examines the latest developments using integrated circuits over the past decade. Also, we present in detail the design considerations of the transmitter and receiver that are the cornerstone of micro-NMR systems.