June 7, 2012 – Silicon Laboratories (Country Manager Jong-Chan Lee), a global leader in high-performance analog-intensive mixed-signal ICs, announced today the introduction of the industry's first 10-bit analog-to-digital converter (ADC) specifically designed for mains power line monitoring needs. Utilizing Silicon Labs' patented CMOS-based digital isolation technology and proven ADC technology, the new Si890x family provides superior line voltage monitoring and protection solutions for power management applications, such as solar inverters, switch-mode and uninterruptible power supplies (UPS), and industrial applications equipped with sensors in high-voltage regions requiring isolated data acquisition.

Isolated ADCs are essential for applications where power consumption from AC mains power supplies must be monitored. The most common solution for these applications today involves using current transformers that combine discrete components and data converters; however, this approach has the disadvantage of increasing the size and complexity of the power supply. While standalone ADCs exist, they require external galvanic isolators to connect to the mains or other high-voltage systems. Although some vendors supply isolated ADCs optimized for motor control, these are also too expensive for the mains monitoring market.

Silicon Labs' Si890x isolated ADC was developed to meet the needs of the mains power monitoring market in a way that other companies have not attempted. The Si890x family is characterized by being much smaller and thinner than transformer solutions. Because the Si890x combines an ADC with isolation capabilities, power measurements can be transmitted by the system controller via an isolated serial port for processing. The Si890x product family features 2.5 and 5 kV isolation that meets the stringent safety requirements of high-voltage systems, such as IEC 60950-1, 61010-1, 60601-1 standards and UL, CSA, and VDE certifications. Providing an isolation barrier life of over 60 years and an operating voltage of up to 1200 V, these isolated ADCs extend the lifespan of high-voltage systems in which they are applied.

Each ADC input is equipped with a 3-channel analog multiplexer (AMUX) that allows a single Si890x isolated ADC to monitor up to three different signals (typically, the AC main voltage and current for the third channel are provided as a spare). The Si890xPWR-KIT evaluation kit is supported for the three products in the Si890x family. This kit includes a master controller that allows developers to quickly and easily connect to an AC line to observe waveforms on an oscilloscope or receive serial data.

"The Si890x follows Silicon Labs' popular Si86xx digital isolator family and is an isolated ADC solution that offers developers the best price-performance ratio for the mains line monitoring market," said Mark Thompson, Vice President of Access, Power, and Sensor Products at Silicon Labs. "The Si890x family will become the new standard for power management applications that need to lower costs and complexity while further enhancing CMTI performance and flexible interface options."

The Si890x family offers three serial interface options: UART, I2C, and SPI. The interface flexibility they provide allows developers to easily integrate and utilize existing communication ports into system designs, and also enables quick and easy connection to isolated ADCs without changing the system controller.

Price and supply
The Si890x isolated ADC is available in a 16-pin SOIC widebody package with a choice of 2.5 or 5kV isolation, and is currently available for both sample and production use. Pricing for the Si890x starts at $1.65 per unit for a volume of 10,000. Silicon Labs also offers the Si890xPWR-KIT evaluation kit ($149) to enable developers to demonstrate and measure AC line voltage (110Vac or 220Vac at 50/60Hz) and AC line current.

For detailed information on Silicon Labs' Si890x isolated ADC product family, as well as inquiries regarding the purchase of samples and development tools, please refer to www.silabs.com/pr/isolation.