Avago Technologies Delivers Industry’s First Precision Optical Isolation Amplifiers Optimized for Voltage Sensing
For general applications, the ACPL-C87A (±1% gain tolerance) and the ACPL-C870 (±3% gain tolerance) are recommended. For high-precision applications such as renewable energy inverters where it is important to accurately track the fluctuating (due to changing sun conditions) DC bus voltage and for high-performance servo and motor drives, the ACPL-C87B (±0.5% gain tolerance) can be used. The voltage sensors features a 1V/V unity gain with low gain drift of -35ppm/˚C and non-linearity is kept to within 0.1% max. The voltage sensors include an active-high shutdown pin which reduces the IDD1 current to only 15µA during standby, which makes the sensors well-suited for battery-powered and other power-sensitive applications.
“This new family of optically-isolated voltage sensors has a high 1 GΩ input impedance, which simplifies the resistor network design by allowing higher-value resistors to be used to scale the voltage.” explains Lee Kheng Jam, Marketing Director for Optocoupler products at Avago. “As a result, it reduces loading power losses, thus achieving better system efficiency.”
Avago Technologies' Optical Isolation Amplifiers have been using advanced Sigma-Delta modulation technology and chopper-stabilized amplifiers to provide accurate, safe, and reliable current and voltage sensing for over 2 decades in motor drives and power converters. Differential outputs on the new devices provide unequaled isolation-mode noise rejection, low offsets, high gain accuracy and stability, and a wide signal bandwidth of 100 kHz..
The built-in reinforced safety insulation and high CMR (common mode rejection) performance prevents erroneous voltage measurements and ensures reliable operation in a noisy environment. The optically-isolated voltage sensors have a 15 kV/µs common-mode transient immunity. Safety approvals include CSA and IEC/EN/DIN EN60747-5-5 with a VIORM of 1230 Vpeak. Additionally, the sensors are UL recognized with 5000 Vrms for 1 minute per UL1577.
The ACPL-C87x voltage sensors are housed in stretch 8-lead SO-8 plastic packages with 8mm creepage and clearance that meet worldwide regulatory safety standards. The sensors also have a wide operating temperature range of -40 to +105 °C.