30% smaller isolation amplifiers meet creepage specifications

ACPL-C78x miniature isolation amplifiers from Avago Technologies are 30% smaller than comparable devices in DIP packages. Despite the reduced sized, these isolation amplifiers still meet 8mm creepage and clearance, and are suitable for safe insulation of working voltages up to 1140V peak voltage (IEC60747-5-2) or 5000Vrms (UL1577).

Isolation amplifiers are mainly used for voltage and current sensing in motor-control applications. Their key advantages, compared to closed-loop Hall-effect sensors, are low offset- and gain-drift over temperature, robustness to common-mode noise, and a low-cost solution with SMD assembly.

Embedded sigma-delta ADC technology, chopper-stabilised amplifiers, and differential circuit topology also combine to provide high isolation-mode noise rejection.

Designed to ignore common-mode transient slew rates as high as 15kV/µs, the ACPL-C78x enhances precision and stability for accurate monitoring of motor currents in highnoise environments. This minimises torque ripple with modern switching-inverter motor drives. Other applications include general analogue-signal isolation where high accuracy, stability, and linearity are required under similarly severe noise conditions.

 

FEATURES 0.00025V/V/°C gain drift vs. temperature 0.3mV input offset voltage 100kHz bandwidth 0.004% non-linearity Gain tolerance at 25°C 1% (ACPL-C78A) 3% (ACPL-C780) 5% (ACPL-C784)

APPLICATIONS Motor phase- and rail-current sensing Inverter current sensing Switched-Mode Power Supply (SMPS) signal isolation General-purpose current sensing and monitoring General-purpose analogue signal isolation

 

 

 

• International Rectifier’s IRS233x, page 081003
• austriamicrosystems’ AS5134, page 081016

 

Avago Technologies / ACPL-C78x