The family of Phototransistor Output AC Sensing Input Optocouplers from ON Semiconductor consists of two gallium arsenide infrared emitting diodes, connected in inverse parallel, driving a silicon phototransistor output in 4, 6, or 8-pin packages. The devices offer a variety of Current Transfer Ratio (CTR) ranges from 20% to 600% at IF = ±1 mA, VCE = 5 V, TA = 25ºC. Other ideal performance characteristics and features of these devices include bi-polar emitter input, built-in reverse polarity input protection, bidirectional AC Input, protection Against Reversed DC Bias, Guaranteed CTR Symmetry of 2:1 Maximum, and half pitch leads for optimum board space savings. The devices achieve the following safety and regulatory approvals: UL1577 #E90700, DIN EN/IEC60747-5-5, VDE #136480, and CSA #1201524. Applications for the devices include AC-DC Merchant Power Supplies, Consumer Appliances, and Industrial Motors.