Broadcom HCPL-7840-300E Optocoupler Isolation Amplifier, SMDIP-8, 3.75kV, 100Kh

The Broadcom HCPL-7840-300E is a high-performance isolation amplifier specifically engineered for precise current sensing in demanding electronic motor drive applications. Its core function is to safely measure motor currents by isolating the high-voltage power stage from the low-voltage control circuitry, a critical requirement for system safety and signal integrity.

In a typical setup, motor current passes through an external shunt resistor, generating a small analogue voltage. The HCPL-7840-300E accurately senses this differential input voltage and transmits a proportional differential output voltage across its high-reliability optical isolation barrier. This output can then be easily converted to a single-ended signal using an external operational amplifier, as illustrated in the recommended application circuit.

This device is built to excel in the harsh electrical environment of modern switching inverter drives, where common-mode voltage can swing by hundreds of volts in mere nanoseconds. It features exceptional common-mode transient immunity, capable of rejecting very high slew rates of at least 10 kV/µs, ensuring stable and accurate readings even under extreme noise conditions.

Key performance characteristics include a wide bandwidth of 100 kHz for capturing dynamic current changes, very low input offset voltage, and excellent gain stability over temperature. Its fully differential circuit topology provides superior noise rejection, making it a reliable and accurate choice for closed-loop motor control, power conversion, and industrial automation systems.

Important Handling Note: This is an ESD-sensitive device. Always observe proper electrostatic discharge precautions during handling and installation to prevent damage.