The ACPL-570xL/573xL/177xL series of hermetically sealed, high-gain optocouplers includes single-, dual-, and quad-channel devices. The 3.3V logic-gate devices enable operation over a –55 to +125°C temperature range, meeting aerospace, industrial, and military applications. The optocouplers allow designers to use low-power components, suiting microprocessor-system interfaces, process-control I/O isolation, voltage-level shifting, and logic-ground isolation. The devices reduce or eliminate the need for extra interface components or voltage converters. Each channel contains a GaAsP LED and an integrated high-gain photon detector. A high-gain output stage features an open-collector output, enabling lower saturation voltage and higher signal speed than typical photo-Darlington optocouplers. The supply voltage for the optocouplers suits operation as low as 3V with no adverse affects on parametric performance. Devices in the series cost $43 (1000) each.