Linear Technology Corp. (LTC, Milpitas, CA) introduced the LTC4214, a negative hot-swap controller in an MSOP package that allows a board with a low-voltage negative supply to be safely inserted and removed from a live backplane. Output current is controlled by three stages of current limiting: a timed circuit breaker, active current limiting, and a fast feed forward path.
A slight over-current condition will trip the circuit breaker if it persists for an adjustable timer period. Larger over-current conditions will be controlled through active current limiting, maintaining a safe power level in the MOSFET. Catastrophic over-current conditions, due to a short-circuit, will cause the circuit breaker to trip immediately, protecting the load and the MOSFET even more quickly than the active current limit loop.
The LTC4214 voltage monitor features programmable under-voltage and over-voltage detectors that disconnect the load whenever the input supply exceeds the desired operating range. A power-good status output can enable the load or a power module at startup or disable it if the circuit breaker trips. The LTC4214 requires a supply of -6V to -16V to operate, and is suitable for -12V systems.
The LTC4214 is offered in a 10-pin MSOP package. All versions are screened to the commercial and industrial temperature ranges. Pricing starts at $2.35 each for 1,000-piece quantities.