Isolated DC/DC Converter for Low-Noise 2-W Power Supplies

Texas Instruments Incorporated introduced a high-efficiency, primary-side feedback transformer driver for isolated 2-W power supplies, which are used in programmable logic controllers, industrial automation and other noise-sensitive data acquisition designs.

The high-efficiency TPS55010 with integrated FETs features a simple and unique Fly-Buck topology to provide isolated power and remove ground loops from analog circuitry and communication interfaces, such as RS-485 and RS-232, from an unregulated 3.3-V or 5-V input. The 2-W converter does not need an optocoupler, and provides up to 85-percent power efficiency.

The isolated DC/DC converter can be used with high-speed digital isolators, such as the ISO721 and ISO722, and isolated transceivers like the ISO1176 isolated Profibus device, the ISO35 isolated 3.3-V RS-485 device and the ISO3086 isolated 5-V RS-485 transceiver. In addition to the TPS55010, TI's popular 1-W DCP010505 open-frame power module with integrated transformer provides simple isolated power conversion and ground-loop elimination.

Features

• 2-W isolated power converter with integrated FETs supports variety of industrial designs. Output voltage is set by a resistor divider and the transformer turns ratio.
• Wide switching frequency range (100 kHz to 2 MHz) offers design flexibility to optimize efficiency and space. Frequency can be synchronized to a master clock to reduce noise in sensitive data acquisition circuitry.
• Supports -40 C to +150 C operating junction temperature and comes in a space-saving, thermally enhanced 3-mm x 3-mm x 1-mm monolithic QFN package.

The TPS55010 is available in volume now from TI and its authorized distributors in a 16-pin, 3-mm x 3-mm thermally enhanced QFN package. Suggested resale pricing is $1.65 in 1,000-unit quantities. The DCP010505 plug-in module comes in a 7-pin SIP package with a suggested resale price of $5.35 in 1,000-unit quantities.