This reference design showcases non-isolated power supply architectures for protection relays with analog input/output and communication modules generated from 5-, 12-, or 24-V DC input. To generate the power supplies the design uses DC/DC converters with an integrated FET, a power module with an integrated inductor for size- and design-time-constrained applications, a HotRod™ package type for applications requiring low EMI and linear regulators (LDOs) for low ripple. Protections include a flat clamp TVS for input transient protection, an eFuse with configurable load current for overload protection and an ideal diode controller for input reversal protection. Additional features include an auto-switching power MUX, an analog temperature sensor, an input OK indication, a “no load” detection and a voltage supervisor.
- Power supplies for communication module: multiple non-isolated supply rails with varying load currents up to 1.5 A using a DC/DC converter with low IQ and EMI, DC/DC converter in HotRod™ package and DC/DC converter with Eco-mode™
- Power supply for analog Input/output modules: ±12-V split-rail supply for analog IO modules generated from a 24-V wide input synchronous buck converter, split rail DC/DC converters and
LDOs and a ±10.5-V split-rail supply generated from 24 V using power modules with an integrated inductor in inverted buck configuration
- Performance testing:
- Tested analog IO power supply performance by interfacing to high accuracy AC analog input and DC analog output reference designs
- Tested communication module power supply performance by interfacing to RS-485 EVMs, CAN EVMs and 10/100 ethernet reference design or 10/100/100 copper or fiber interface EVM
- Pre compliance testing: tested power supply for electrical fast transients (EFT) and surge per IEC61000-4 and radiated emission per CISPR22