HCPL-0720

HCPL-0720 is a high-speed optocoupler (optoisolator) from Avago/Broadcom. It provides galvanic isolation between the input LED and the output transistor, allowing digital signals to pass while keeping the two sides electrically separate. Key points:
- Isolation: typically up to about 5 kV RMS between input and output.
- Speed: fast propagation delay suitable for TTL/CMOS logic.
- Output: TTL/CMOS-compatible, usually an open-collector transistor; requires a pull-up resistor on the output side.
- Input: LED driven with a few milliamps (via a series resistor) to switch the output.
- Packaging: common 8-pin DIP or SO-8.
- Applications: microcontroller or logic isolation from high-voltage/noisy sections (power electronics, motor drives, mains systems).
Basic use: drive the input LED with your logic, and read the isolated output with a pull-up to the logic supply on the output side. Ensure proper CTR variation, polarity, and adequate layout for isolation.

Common equivalents to the HCPL‑0720 include:
- ACPL‑0720 (Avago/Broadcom — same family/rebrand)
- Vishay 6N137 (high‑speed logic optocoupler)
- Toshiba TLP2361 (high‑speed optocoupler)
- HCPL‑0500/ACPL‑0500 (similar function; check specs)
Note: verify pinout, speed, propagation delay, logic levels and isolation voltage against your application before substituting.

Key features of HCPL-0720:
- Electrically isolated high-speed optocoupler amplifier (input to output isolation up to 5 kV rms).
- Logic-compatible output on the output side (TTL/CMOS level, powered from 4.5–5.5 V).
- High-speed performance suitable for digital and moderate-speed analog signals; low propagation delay.
- LED input with modest drive current; good CTR for reliable switching.
- High common-mode transient immunity (robust against fast dv/dt on the input side).
- Industrial temperature range (typical -40°C to +85°C).
- Package: 8-pin (DIP/SO-8) for easy PCB mounting.
- Applications: microcontroller isolation, isolated data links, sensor/ instrumentation interfaces, fault-tolerant systems.

The HCPL-0720 is supplied in an 8-pin package (DIP or SOIC). Pin functions (by side/function, not strict numbering) are:
- Input side: LED anode and LED cathode (optical input).
- Output side: phototransistor/photodiode output pins (collector and emitter) providing the isolated logic output (open-collector style, TTL/CMOS compatible with pull‑up).
- Power: VCC and GND for the output/receiver side.
- Two remaining package pins are no-connects (NC) or substrate ties depending on manufacturer/package variant.
In short: 8 pins total — LED input (2), isolated output transistors (2), VCC & GND (2), plus 2 NCs.

The HCPL-0720 is manufactured by Broadcom Inc. (originally produced under Hewlett‑Packard/Agilent and later Avago brand names). Broadcom is a multinational semiconductor company that designs and supplies a wide range of semiconductor and infrastructure solutions, including optoelectronic components such as optocouplers, analog and mixed‑signal ICs, and networking chips.

HCPL-0720 is a high‑speed optocoupler used to provide galvanic isolation between logic/signal sides and high‑voltage or noisy circuits. Common applications:
- Isolated interfaces for microcontrollers/MCUs in power electronics (SMPS, motor drives, inverters)
- Isolated data paths in industrial automation (SPI/I2C/UART with isolation)
- Instrumentation and data acquisition systems needing noise/ground-loop immunity
- Safety-critical equipment and medical/diagnostic devices within isolation requirements
In short: any scenario requiring fast, reliable signal isolation between low‑voltage control logic and high‑voltage/noisy environments.

The HCPL‑0720 optocoupler is supplied in 8‑pin packages: through‑hole DIP‑8 and surface‑mount SOIC‑8 (standard SO‑8).