Correlation is a fundamental operation in radar/ communication signal processing. Enabling efficient reconfigurable correlation at high frequencies with wide bandwidths and high dynamic range is a fundamental challenge. This article presents a direct-RF wideband analog correlator that utilizes a novel margin computation paradigm replacing traditional multiply-and-accumulate (MAC) with analog addition and thresholding to enable energy-efficient analog computation. A high-efficiency charge-domain realization is proposed and implemented in 65-nm CMOS occupying 0.97 mm2. The analog correlator IC supports 5-GS/s inputs, a large correlation length of 1024, and 8-bit computing accuracy with a high energy efficiency of 152 TOPS/W. Practical applications of typical high-speed correlation are also demonstrated through system-level measurements such as radar signal detection, and code-domain processing.