Isolation Amplifier operates in high-noise conditions.
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Press Release Summary:
Model ACPL-782T-000E automotive isolation amplifier features high CMR capability, which provides precision and stability needed to accurately monitor motor current in high-noise motor control environments. It is designed to ignore very high common-mode transient slew rates, of at least 10 kV/µs, and senses analog voltage drop caused by motor or battery current flow through external resistor. Product is contained in compact, auto-insertable, 8-pin DIP package.
Original Press Release:
ACPL-782T-000E: Plastic Automotive Miniature Isolation Amplifier
The ACPL-782T automotive isolation amplifier family was designed for current sensing in electronic motor drives and battery system. In a typical implementation, motor currents or battery current flow through an external resistor and the resulting analog voltage drop is sensed by the ACPL-782T. A differential output voltage is created on the other side of the ACPL-782T 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 ACPL-782T was designed to ignore very high common-mode transient slew rates (of at least 10 kV/µs).
The high CMR capability of the ACPL-782T 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 isolation applications requiring high accuracy, stability, and linearity under similarly severe noise conditions. For general applications, we recommend the ACPL-782T (gain tolerance of ±3%). For precision applications Avago Technologies offers the ACPL-782T with part-to-part gain tolerance of ±1%. The ACPL-782T utilizes sigma delta analog-to-digital converter technology, chopper stabilized amplifiers, and a fully differential circuit topology.
Together, these features deliver unequaled isolation-mode noise rejection, as well as excellent offset and gain accuracy and stability over time and temperature. This performance is delivered in a compact, auto-insertable, industry standard 8-pin DIP package that meets worldwide regulatory safety standards. (A gull-wing surface mount option #300 is also available).
Features
o 15 kV/µs Common-Mode Rejection at VCM = 1000V
o Compact, Auto-Insertable Standard 8-pin DIP Package
o 30ppm Gain Drift vs. Temperature
o 0.3 mV Input Offset Voltage
o 100 kHz Bandwidth
o 0.004% Nonlinearity
o Worldwide Safety Approval (pending):
o UL 1577 (3750 VRMS/1 min.) and
o CSA
o IEC/EN/DIN EN 60747-5-5
o Qualified to AEC-Q100 Test Guidelines
o Automotive Operating Temperature -40 to 125°C
o Advanced Sigma-Delta A/D Converter Technology
o Fully Differential Circuit Topology
Applications
o Automotive Motor Inverter Current/Voltage Sensing
o Automotive AC/DC and DC/DC converter current/voltage sensing
o Automotive Battery ECU Monitoring
o Automotive Motor Phase Current Sensing
o Isolation Interface for Temperature Sensing
o General Purpose Current Sensing and Monitoring
Benefits
o Part-to-part gain tolerance of ±2% over temperature allowing high precision applications
o Performance specified for automotive isolation amplifier applications over temperature range: -40°C to 125°C.
o Qualified to Automotive AEC-Q100 stress test guidelines that ease the designer designs in harsh operating conditions.
o Good CMR - Prevent erroneous signals and ensure reliable operation under noisy environment
o Safety regulatory approvals (UL1577, IEC/EN/DIN EN 60747-5-5 and CSA Pending) that meets regulatory requirement
