Single-channel optocoupler for isolated signal transfer
The onsemi H11A817300W is a single-channel optocoupler with a phototransistor output, designed to transfer DC signals across a galvanic isolation barrier of 5300Vrms. This isolation rating is typical for reinforced insulation in industrial and power-supply applications, where it protects low-voltage control circuits from high-voltage transients on the load side. Housed in a 4-DIP (0.400-inch, 10.16mm) through-hole package, it mounts directly into a standard 2.54mm-pitch socket or PCB. The tube packaging suits medium-volume assembly where individual pick-and-place is not required.
Current transfer ratio and switching speed
The current transfer ratio (CTR) spans 50% to 600% at a forward current of 5mA — a wide range that accommodates varying LED drive strengths. A minimum CTR of 50% means the output transistor can sink at least 2.5mA when the input LED is driven at 5mA, which is sufficient to drive a logic gate input or a low-power relay coil directly. Typical rise and fall times are 2.4µs each, giving a combined propagation delay of under 5µs for most signal edges. This suits data rates up to roughly 100 kbps, adequate for status feedback, fault signaling, or slow serial buses like I²C at standard mode.
Temperature range and forward drive
Rated for operation from -55°C to +100°C, the H11A817300W covers industrial and extended-temperature environments. The input LED has a maximum forward current of 50mA and a typical forward voltage of 1.2V, so a series resistor of about 220Ω from a 5V supply limits the LED current to a safe 17mA. Onsemi lists this part as obsolete. For existing BOM lines, sourcing is through independent channels; availability and pricing are confirmed per RFQ against the required quantity and date-code preference.