Hot-Swap Controllers Take Up Position In Telecomm Power Systems

Touted as the industryÕs first SOT23, -48V hot-swap controllers for telecomm line cards, the MAX5900/MAX5901 allow the line cards to be safely inserted and removed from a live backplane without causing a glitch on the negative power supply rail. Dubbed the Simple Swappers, the ICs drive an external N-channel MOSFET and do not require an external sense resistor for overcurrent shutdown. They include an undervoltage lockout feature that disconnects power to the load if the input voltage is too lowÑlockout is set to -31.5V, but can be set to any voltage between -9V and -100V. Capable of operating at a -9V to -100V input range, the controllers are available in three functional versions. One version automatically restarts the controller after a circuit breaker shutdown; the second version latches the controller off after a circuit breaker shutdown; and the third version omits the circuit breaker function. The MAX5900 has an active-low power-good status output and the MAX5901 has an active-high power-good status output. Prices start at $1.04 each/1,000. MAXIM INTEGRATED PRODUCTS, Sunnyvale, CA. (800) 998-8800.