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Description

The HCPL-7840 isolation amplifier 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 differential output voltage is created on the other side of the HCPL-7840 optical isolation barrier.

This differential 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 common mode transient slew rates (of at least 10 kV/μs).

Features

• 15 kV/μs common-mode rejection at VCM = 1000 V

• Compact, auto-insertable standard 8-pin DIP package

• 0.00025 V/V/°C gain drift vs. temperature

• 0.3 mV input offset voltage

• 100 kHz bandwidth