Data Sheet HCPL-7800A/HCPL-7800
Isolation Amplifer 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.
The product can also be used for general analog signal …
