A reinforced insulation power supply for RS485 and RS232 transceiver ICs separates Pulse Electronics’ latest high-isolation switch-mode power transformers from comparable devices. The PH9185NL transformers are designed on a surface-mount platform with offset pins to maintain a large separation between primary and secondary circuits. They use an RS485/232 communications bus as a low-cost alternative to Ethernet. Construction of the transformers has been certified by UL/TUV for reinforced insulation up to 400 V. The design, which guarantees 8-mm creepage and 4000-V rms isolation voltage, employs the company’s Class F insulation system. Seven turns ratios provide the required voltage to the IC from a range of low voltage levels, delivering up to 3 W of power. The PH9185NL series is compatible with Maxim’s MAX253 power driver. Applications include industrial-control, building-automation, and smart-grid systems, among many others.