Avago precision isolation amps target industrial motor control, renewable energy markets

avagoprecisionampSan Jose, Calif. — Avago Technologies has launched three miniature precision isolation amplifiers with increased accuracy, bandwidth and high insulation thanks to proprietary optical isolation technology.

Based on sigma-delta analog-to-digital converters and chopper stabilized amplifiers, the isolation amplifiers feature high gain accuracy, low temperature drift, 3.3 V/5 V output supply operation and a wide -40°C to +105°C operating temperature range.

These devices are housed in a stretched SO-8 package that offers a footprint 30 percent smaller than the standard DIP-8 package. When mounted on a printed-circuit board (PCB), it occupies a space that is a fraction of that for a traditional Hall Effect or transformer-based isolation amplifier, said Avago.

The series is implemented with a fully differential circuit topology with a gain accuracy of +/-0.5 percent (ACPL-C79B), +/-1 percent (ACPL-C79A), and +/-3 percent (ACPL-C790). Normalized gain drift is -50 ppm/°C. With a 200-kHz bandwidth and 1.6 μs response time, the ACPL-C79x captures transients during short circuit and overload conditions. Operating from a single 5-V supply, the isolation amplifier series features a nonlinearity of 0.05 percent and a SNR of 60 dB.

The ACPL-C79x high common-mode transient immunity of 15 kV/μs provides the precision and stability needed to accurately monitor current in high-noise motor control environments. This ensures smoother control with less “torque ripple” in many motor control applications, said Avago.

Pending safety and regulatory approvals include:

–IEC/EN/DIN EN 60747-5-5: 1140 Vpeak working insulation voltage
–UL 1577: 5000 Vrms/1 minute double protection rating
–CSA: Component Acceptance Notice #5

The ACPL-C97x targets industrial automation and instrumentation, renewable energy, and HVAC markets, including applications such as motor phase and rail current sensing, servo motor drive, switching power supply feedback isolation, DC link voltage monitoring, inverter current sensing and switching power supply feedback isolation.

The devices feature a low input offset voltage and drift of 0.6 mV and 3μV/°C as well as 0.5-mm internal package distance-through-insulation (DTI) and 8 mm minimum package creepage and clearance for high insulation ratings. The devices are RoHS compliant.

Availability: Samples and production quantities are available now through Avago’s direct sales channel and worldwide distribution partners.
Pricing: The ACPL-C79B, ACPL-C79A and ACPL-C790 are priced at $6.25, $5.00 and $3.75, respectively, each in quantities of 10,000.
Resources: Avago’s isolation amplifier and isolation product portfolio