HCPL-817-50AE

HCPL-817-50AE is a high-speed optocoupler (optical isolator) in an 8-pin package. It provides galvanic isolation between the input LED and the output transistor, enabling safe interfacing between low-voltage logic and higher-noise or higher-voltage circuits.
Key points
- Isolation: typically several kilovolts RMS between input and output.
- Input: LED forward current drives the device; CTR (current transfer ratio) varies with temperature and age.
- Output: logic-compatible transistor output that usually requires a pull-up to a logic supply (TTL/CMOS-friendly).
- Speed: fast enough for many digital-isolation needs; suitable for microcontroller interfaces, power electronics, and automation.
- Package: common 8-pin DIP or SO-8; standard pinout with separate input and output sides.
- Variants: -50AE is a specific ordering code within the HCPL-817 family; exact electricals (CTR, voltage ratings, temp/grade) are in the datasheet.
If you’re designing, check the datasheet for CTR specs, V_out limits, isolation voltage, operating/storage temp, and recommended operating conditions.

HCPL-817-50AE is a high‑speed optocoupler with a transistor output for galvanic isolation. Key features:
- Optocoupler with input LED and output transistor for digital isolation
- High isolation voltage (up to several kV RMS) between input and output
- High common‑mode transient immunity (CMTI)
- Fast propagation delay suitable for logic interface timing
- TTL/CMOS‑compatible output; typically requires a pull‑up resistor
- Wide operating temperature range
- Pb‑free/RoHS compliant
- Package options: 8‑pin (DIP/SO‑8) variants
Applications include microcontroller and logic interfacing, PWM control, motor drives, and other systems requiring reliable signal isolation.

The HCPL-817-50AE is an 8-pin DIP (through-hole) optocoupler package; RoHS Pb-free variant.

- Manufacturer: Broadcom Inc. (Avago Technologies lineage)
- What kind of company: A global semiconductor company that designs and manufactures integrated circuits and optoelectronic devices for telecom, data center, networking, industrial, and other markets.

- Galvanic isolation between low-voltage control logic and high-voltage/power circuitry
- Isolated data/control signaling for switch-mode power supplies, motor drives, and inverters
- Isolated feedback in SMPS control loops
- Industrial automation, PLCs, sensors, and instrumentation
- Medical and telecom equipment requiring safety isolation

Equivalent optocouplers (transistor-output) to HCPL-817-50AE include:
- Sharp PC817
- Sharp EL817
- Everlight EL817
- Lite-On LTV-817
- On Semiconductor FOD817
- Vishay IL817
These are cross-compatible in CTR and package (8-pin DIP/SO-8); verify CTR, speed and isolation ratings in datasheets for exact replacement.