The H11A1FR2M is officially marked Obsolete by onsemi.
7500Vpk isolation — what it means for the BOM
The 7500Vpk isolation rating is the peak repetitive voltage the optocoupler withstands between input and output. For a 230VAC line monitoring circuit, this provides a 32× safety margin over the peak line voltage (325V), comfortably exceeding reinforced insulation requirements per IEC 60950-1. The 6-SMD gull wing package with 7.62mm creepage distance supports this isolation class.
CTR and switching speed — the real-world limits
Minimum current transfer ratio is 50% at If=10mA, Vce=10V. At the 10mA forward current, the output transistor saturates to 400mV max (Vce(sat)), keeping the logic-level output clean for 5V or 3.3V digital inputs. Turn-on and turn-off times are both 2µs typical — this limits the practical switching frequency to about 50kHz before pulse-width distortion becomes significant. For 10kHz PWM or serial data at 115.2kbps, the 2µs edges are well within margin.
Package and board-fit for the 6-SMD gull wing
The 6-SMD gull wing package (supplier device package 6-SMD) has a 7.62mm body width and 0.4mm lead pitch. The gull wing leads extend 2.54mm from the body — the footprint requires a 10.16mm × 6.6mm land pattern. The 1.18V typical forward voltage at 10mA means a 240Ω series resistor from a 5V rail sets the LED current. Maximum continuous forward current is 60mA, so the resistor can be sized for 20mA to leave headroom for temperature derating.