Isolated switch controller protects and monitors up to 1000VDC power supplies

Linear Technology has introduced the LTM9100 µModule (micromodule), all-in-one Isolated Anyside switch controller protects and monitors high voltage DC power supplies up to 1000V. High voltage supplies used in industrial, datacom, avionic and medical applications require a controlled turn-on, with isolation needed for control circuit protection, operator safety and breaking ground paths. Alternative relay-based or discrete solutions are bulky, complex, component-intensive and lack safety certifications. The innovative device saves design time, certification effort and board area by wrapping all the needed functionality, including isolated power and digital telemetry, in a compact BGA package. A 5kVRMS galvanic isolation barrier inside the device separates the digital interface from the switch controller, driving an external N-channel MOSFET or IGBT switch. To guarantee a robust isolation barrier, the controller is production-tested to 6kVRMS and will be recognized by the component-level UL 1577 standard, saving months of certification time for the end equipment manufacturer. Isolated digital measurements of load current, bus voltage and temperature are accessed via the I²C/SMBus interface, enabling power and energy monitoring of the high voltage bus. Due to its isolated nature, the device is easily configured for high side, low side (ground return) and floating applications. Inrush current is minimized by soft-starting the load, and the supply is protected from overload and short-circuits with a current-limited circuit breaker. The LTM9100 is versatile enough to control inrush current in hot-swappable cards, AC transformers, motor drives and inductive loads. Adjustable undervoltage and overvoltage lockout thresholds ensure that the load operates only when the input supply is in its valid range. A fully integrated DC-DC converter, including the transformer, powers the isolated switch control side. Specified over the -40C to 105C temperature range, the device is offered in a 22mm x 9mm x 5.16mm BGA package, with 14.6mm of creepage distance between the logic side and the isolated side.