The ONET4291PA is a versatile, high-speed, rate-selectable limiting amplifier for multiple fiber-optic applications with data rates up to 4.25 Gbps. The device provides a two-wire interface, which allows digital bandwidth selection, digital output amplitude selection, and digital loss of signal threshold adjust. This device provides a gain of about 43 dB, which ensures a fully differential output swing for input signals as low as 5 mVp-p. The ONET4291PA provides loss-of-signal detection with either digital or analog threshold adjust. The part is available in a small-footprint, 4-mm × 4-mm, 16-terminal QFN package. It requires a single 3.3-V supply. This power-efficient, rate-selectable limiting amplifier is characterized for operation from -40°C to 85°C ambient temperature.