This paper describes an analog CMOS IC for fast and fully-parallel finite-difference time-domain (FDTD) simulations of 2D electromagnetic (EM) problems. The chip uses discrete-time switched-current (SI) networks to model Maxwell's equations in 2D while minimizing the effects of device mismatch on solver accuracy. A prototype design in 180 nm technology implements a 16x16 solver grid within an active area of 44.5 mm2 while consuming 345 mW at a clock frequency of 20 MHz.