Analog Devices Introduces Digital Isolator with Integrated Transformer Driver & PWM Controller
Analog Devices, Inc., a global leader in high-performance semiconductors for signal-processing applications, today introduced the industry’s first digital isolator with an integrated transformer driver and PWM (pulse-width modulation) controller in a single package.
The integration of these components into a small, surface mount 20-lead SSOP (shrink small outline package) enables the new four-channel digital isolator to reduce board space by up to 30% and achieve cost reductions of 10% while simplifying the development of systems requiring isolated data and power. The product enables designers to implement an isolated dc-to-dc converter that provides up to 2W of regulated, isolated power at 3.3 to 30V from a 5.0V input supply or 3.3V supply. Analog Devices’ new ADuM347x digital isolators are ideal for applications that require isolated data and isolated power, including data acquisition, industrial process control using Fieldbus, and building control.
The new devices expand ADI’s iCoupler digital isolation portfolio, which provides the most extensive range of isolation technology in the industry. The ADuM347x isolators, along with other products in the portfolio, enable designers to implement isolation in their designs without the cost, size, power, performance, and reliability constraints found with traditional isolation products, such as optocouplers.
The ADuM347x four-channel digital isolators include the ADuM3470, ADuM3471, ADuM3472, ADuM3473, and ADuM3474 products. These four-channel products provide four independent data isolation channels in various channel configurations and data rates up to 25 Mbps. Each device also provides a transformer driver and PWM controller with isolated feedback to provide a regulated output with up to 70% efficiency. The ADuM347x also offers 2500V rms isolation using ADI’s patented iCoupler digital isolation technology.
The EVAL-ADuM3471EBZ evaluation board is comprised of two independent and isolated dc-to-dc converter circuits that demonstrate single and double supply applications for the ADuM347x digital isolators. The dc-to-dc converter switching frequency may be adjusted within the range of 200kHz to 1MHz. The board also supports a variety of I/O configurations to allow easy evaluation of the ADuM347x devices.
With more than 450 million channels deployed, ADI’s proven iCoupler technology is based on chip-scale transformers, rather than on the LEDs and photodiodes found in optocouplers. Transformers support higher data rates, consume less power, and are more stable over life as compared to LEDs and photodiodes. By fabricating the transformers directly on-chip using wafer-level processing, iCoupler channels can be integrated with each other and other semiconductor functions at low cost. iCoupler transformers are planar structures formed from CMOS and gold metal layers. A high breakdown polyimide layer underneath the gold layer insulates the top transformer coil from the bottom resulting in the most reliable and highest level of digital isolation available. CMOS circuits connected to the top coil and bottom coil provide the interface between each transformer and its external signals.