DESCRIPTION
The Broadcom® HCPL-7800A/HCPL-7800 (hereinafter referred to as HCPL-7800(A)), isolation amplifier family is 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-7800(A). A differential output voltage is created on the other side of the HCPL-7800(A) 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. Because common-mode voltage swings of several hundred volts in tens of nanoseconds are common in modern switching inverter motor drives, the HCPL-7800(A) is designed to ignore very high common-mode transient slew rates (of at least 10 kV/µs). The high CMR capability of the HCPL-7800(A) isolation amplifier provides the precision and stability needed to accurately monitor motor current in high-noise motor control environments, providing for smoother control (less “torque ripple”) in various types of motor control applications.
Broadcom
