Systems such as fibre optic networks are the targeted beneficiaries of Linear Technology's latest offering; a voltage controller for protecting boards and backplanes. The LTC4224 enables safe insertion and removal of a module into a rail by limiting any inrush currents large enough to create a glitch on the rail, which can cause other plug-in modules to malfunction.
This part has been designed for hot swap operation and offers independent turn-on and adjustable ramp for its 1V to 6V voltage supplies. An internal diode OR circuit ensures that the LTC4224 is properly supplied with power by one of the two monitored supplies – whichever is greater. This allows the LTC4224 to control a supply voltage as low as 1V, provided the other supply is 2.7V or greater.
An adjustable current limit allows users to match the current limit threshold to their load, while a 5ms electronic circuit breaker monitors for an overcurrent condition and protects the external MOSFETs against shorts or excessive load currents. Peak fault currents are controlled in less than 1¼s and an optional gate capacitor can be used to adjust the gate slew rate. Otherwise, all traditional hot swap timing parameters are internally generated, which saves on board area.
The LTC4224 is available in two versions: the LTC4224-1 latches off after a fault, whereas the LTC4224-2 provides automatic retry after a fault. The part also comes in both commercial and industrial grades. It comes in a 10-lead 3mm x 2mm DFN or 10-lead MSOP RoHS compliant package.