HCPL-7840-500E

The HCPL-7840 isolation amplifi er family was designed for current sensing in electronic motor drives. In a typical implementation, motor currents fl ow through an external resistor and the resulting analog voltage drop is sensed by the HCPL-7840. A diff erential output voltage is created on the other side of the HCPL-7840 optical isolation barrier.
This diff erential output voltage is proportional to the motor current and can be converted to a single-ended signal by using an op-amp as shown in the recommended application circuit. Since common-mode voltage swings of several hundred volts in tens of nanoseconds are common in modern switching inverter motor drives, the HCPL-7840 was designed to ignore very high commonmode transient slew rates (of at least 10 kV/μs).