5300Vrms isolation in a 4-DIP body
The H11A817A300 is a single-channel optocoupler with a transistor output, rated for 5300Vrms of input-to-output isolation — enough for reinforced insulation in mains-powered equipment where the secondary side needs galvanic separation from the primary control logic. Housed in a 4-DIP (0.300", 7.62mm) through-hole package, it mounts into standard DIP sockets or solders directly into a PCB. The 4-DIP footprint is a common form factor for optocouplers, so swapping it on a board without a layout change is straightforward — no lab bench needed, just a desoldering pump and a steady hand. The current transfer ratio (CTR) is specified at 80% minimum and 160% maximum, both measured at If=5mA. This bin ensures consistent gain across the batch — a 5mA forward current on the LED side yields 4-8mA on the output transistor side, which is enough to drive a logic gate input or a small relay coil directly.
Temperature range and switching speed
Rated for operation from -55°C to +100°C, the H11A817A300 covers industrial temperature bands — it handles cold starts in outdoor enclosures and the heat near a power supply without derating the isolation or CTR. Typical rise and fall times are 2.4µs each, giving a combined propagation delay of roughly 4.8µs. That limits the usable switching frequency to about 100 kHz for clean pulse transmission — fast enough for most isolated feedback loops, serial data at moderate baud rates, or PLC input modules, but not for high-speed digital isolator applications.
onsemi lists the H11A817A300 as obsolete. No official successor part number is recorded — the replacement path is either a functionally equivalent optocoupler in the same 4-DIP footprint or a surplus buy of this exact code through independent distribution. The part is sourced to order against an RFQ.