15 Mbps open-collector optocoupler for industrial isolation
The Renesas PS9821-1-F3-AX is a single-channel, DC-input optocoupler from the NEPOC series with an open-collector output rated for 15 Mbps data rate and 2500 Vrms isolation.
Data rate of 15 Mbps supports Profibus, DeviceNet, and other industrial fieldbuses running at 12 Mbps or lower. Isolation rating of 2500 Vrms covers basic insulation for 240 VAC mains-powered equipment. The 15 kV/µs CMTI ensures the output stays clean when the input side experiences fast voltage transients from IGBT switching or relay coil kickback — a common failure point in motor drives and inverters. Forward voltage (Vf) typical 1.65 V with a 20 mA max forward current means the LED side can be driven directly from a 3.3 V logic output through a current-limiting resistor. Rise/fall times of 20 ns and 5 ns respectively, combined with the 75 ns propagation delay, give enough timing margin for most 15 Mbps NRZ serial links.