These optoisolated feedback amplifiers consist of the industry standard TLV431 precision programmable reference with a 1% reference voltage tolerance, and an optocoupler. The devices are primarily intended for use as the error-amplifier/reference/isolation-amplifier element in isolated ac-to-dc power supplies and dc-to-dc converters. The optocoupler is a gallium-arsenide (GaAs) light-emitting diode that emits at a wavelength of 940 nm, combined with a silicon phototransistor. The current transfer ratio (CTR) ranges from 100% to 400% in the standard version. The TPS5908A and TPS5910A versions with 150%-to-300% CTR are available for higher-performance applications. All versions enable power-supply designers to reduce component count and save space in tightly packaged designs. The tight-tolerance reference eliminates the need for adjustments in many applications.