The HCPL-7800(A) isolation amplifier family was designedfor current sensing in electronic motor drives. In a typicalimplementation, motor currents flow through an externalresistor and the resulting analog voltage drop is sensedby the HCPL-7800(A). A differential output voltage iscreated on the other side of the HCPL-7800(A) opticalisolation barrier. This differential output voltage is proportionalto the motor current and can be converted toa single-ended signal by using an op-amp as shown inthe recommended application circuit. Since commonmodevoltage swings of several hundred volts in tens ofnanoseconds are common in modern switching invertermotor drives, the HCPL-7800(A) was designed to ignorevery high common-mode transient slew rates (of at least10 kV/µs).The high CMR capability of the HCPL-7800(A) isolationamplifier provides the precision and stability needed toaccurately monitor motor current in high noise motorcontrol environ-ments, providing for smoother control(less “torque ripple”) in various types of motor controlapplications.The product can also be used for general analog signalisolation applications requiring high accuracy, stability,and linearity under similarly severe noise con-ditions.For general applications, we recommend the HCPL-7800(gain tolerance of ±3%). For precision applications AvagoTechnologies offers the HCPL-7800A with part-to-partgain tolerance of ±1%. The HCPL-7800(A) utilizes sigmadelta (Σ−∆) analog-to-digital converter technology,chopper stabilized amplifiers, and a fully differentialcircuit topology.Together, these features deliver unequaled isolationmodenoise rejection, as well as excellent offset andgain accuracy and stability over time and temperature.This performance is delivered in a compact, auto-insertable,industry standard 8-pin DIP package that meetsworldwide regulatory safety standards. (A gull-wingsurface mount option #300 is also available).
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
Worldwide Safety Approval: UL 1577 (3750 Vrms/1 min.) and CSA, IEC/EN/DIN EN 60747-5-2