3750Vrms isolation in a 4-SMD gull-wing package
The FODM121R2 is an onsemi single-channel phototransistor optoisolator rated for 3750Vrms isolation between input and output. The 4-SMD gull-wing package is a standard surface-mount footprint for reflow assembly, and the DC input type means the LED side is driven by a simple forward current — no AC drive conditioning needed.
CTR spread and output drive — 50% min at 5 mA
Current transfer ratio spans 50% minimum to 600% maximum at If=5 mA. The 50% floor is the design anchor: at 5 mA LED current the transistor side must sink at least 2.5 mA into the load. The wide CTR ceiling means the same part can drive a logic gate input with a weak LED drive — useful when the microcontroller pin current is tight. Output side handles up to 80V Vce and 80 mA continuous collector current. The 400 mV Vce saturation at rated current keeps conduction loss low in the on-state. Rise and fall times are 3 µs typical — fast enough for 10 kHz switching or DC-level sensing, but not for high-speed isolated data links.
The FODM121R2 operates from -40°C to 110°C. The 110°C top end covers motor-drive control boards near the heatsink, outdoor base-station power supplies, and factory-floor PLC modules. The -40°C low end handles cold-start in unheated cabinets or northern-climate telecom shelters.
Active lifecycle, ROHS3, tape-and-reel delivery
Supplied in Tape & Reel (TR) or Cut Tape (CT), which matches pick-and-place feeders for volume assembly or small-batch prototyping.