Isolated Anyside switch controller for 1000V DC power supplies

The LTM9100 µModule from Linear Technology is an all-in-one isolated Anyside switch controller which protects and monitors DC power supplies of 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.

According to the company, the LTM9100 saves design time, certification effort and board area by including all the needed functionality, including isolated power and digital telemetry, in a compact BGA package.

A 5kV RMS galvanic isolation barrier inside the LTM9100 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 6kV RMS and will be recognised by the component-level UL 1577 standard.

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 LTM9100 is configured for high side, low side ground return and floating applications. Inrush current is minimised by soft-starting the load, and the supply is protected from overload and short-circuits with a current-limited circuit breaker.

The micromodule can 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 temperatures ranging from −40 to 105°C, the LTM9100 is offered in a 22 x 9 x 5.16mm BGA package, with 14.6mm of creepage distance between the logic side and the isolated side.

Peggy Lee