What the 7500Vpk isolation means for a BOM line
The 4N37FR2M is a single-channel optocoupler from onsemi with a DC input and a transistor-with-base output. Its headline spec is 7500Vpk isolation — this is the peak voltage the part withstands between input and output, relevant for safety isolation in power supplies, motor drives, and industrial control interfaces where galvanic separation is required by IEC 60950 or similar standards. The minimum current transfer ratio of 100% at 10 mA forward current means the output transistor saturates reliably when the LED is driven at 10 mA, with headroom for degradation over temperature and time. Typical turn-on and turn-off times are 2 µs each — fast enough for 100 kHz switching signals in isolated gate drive or feedback loops.
Rated for -55°C to 100°C operating ambient, this optocoupler suits environments from cold storage to engine-bay electronics.
Obsolete — sourcing reality for the 4N37FR2M
onsemi has marked the 4N37FR2M as obsolete.