A7840 IC-Isolation Amplifier IC

The HCPL-7840 isolation amplifier family was designed for current sensing in electronic motor drives. In a typical implementation, motor currents flow 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. 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/ms).

Features/Specs:

15 kV/ms Common-Mode Rejection at VCM = 1000 V
Compact, Auto-Insertable Standard 8-pin DIP Package
0.00025 V/V/ degrees C Gain Drift vs. Temperature
0.3 mV Input Offset Voltage 100 kHz Bandwidth
0.004% Nonlinearity
Worldwide Safety Approval: UL 1577 (3750 Vrms/1 min.) and CSA (pending), IEC/EN/DIN EN 60747-5-2 (option 060 only)
Advanced Sigma-Delta (S-D) A/D Converter Technology
Fully Differential Circuit Topology
0.8 mm CMOS IC Technology