Isolated Error Amplifiers Outperform Optocouplers and Shunt Regulators in Power Supply Applications

Analog Devices, Inc. (NASDAQ: ADI), a global leader in high-performance semiconductors for signal-processing applications and a pioneer in digital isolator technology, today introduced isolated error amplifiers that provide power supply designers with a higher performing, single-chip alternative to isolation techniques based on optocouplers and shunt regulators. Designed for linear feedback power supplies using primary side controllers, the ADuM3190 and ADuM4190 isolated error amplifiers have a 400-kHz bandwidth, with 0.5% typical initial accuracy at 25°C and 1% total accuracy over the extended temperature range of –40˚C to +125˚C. This provides manufacturers of ac-to-dc and dc-to-dc power supplies, including those that are DOSA (Distributed-power Open Standards Alliance)-compliant, with a significant upgrade in speed and operating temperature range, as well as a 5× improvement in transient response.

• View product pages, download data sheets and order samples: http://www.analog.com/ADuM3190 and http://www.analog.com/ADuM4190
• View discussions and FAQs on Analog Devices’ interface and isolation products on EngineerZone™, an online technical support community: http://ez.analog.com/community/interface-isolation

Designed with ADI’s iCoupler® digital isolation technology, the ADuM3190 and ADuM4190 eliminate the CTR (current-transfer ratio) of optocouplers that degrades over the lifetime of the devices and limits operation to 85˚C. The ADuM3190 and ADuM4190 include a highly accurate 1.225-V reference and a wideband operational amplifier that can be used to set up a variety of commonly used power supply loop compensation techniques.

ADuM3190/4190 Isolated Error Amplifiers Key Features

• Bandwidth: 400 kHz
• 0.5% initial accuracy at 25°C
• 1% total accuracy over –40˚C to +125˚C
• Low power operation: