Micrel Semiconductor Announces the MIC2544 and MIC2548 High-Side MOSFET Switches
Micrel Semiconductor Inc. (San Jose, CA) announced that it has made available fully protected high-side MOSFET switches with accurate, user-adjustable current limiting. These single-channel switches, the MIC2544 and MIC2548, are designed for power-distribution applications in USB and advanced configuration and power interface designs, as well as in hot-swap applications.
Both of the new devices are single-channel, protected power-distribution switches with user-adjustable current limiting in the range of 100mA to 1.5A nominal, and 80 milliohm typical on-resistance. Foldback current-limiting ensures that the output current during a fault will not exceed the current-limit range determined by the user's choice of an external current-limit set resistor.
Fault-flag outputs on the MIC2544 and MIC2548 indicate current-limit and thermal shutdown conditions. A circuit-breaker function is incorporated into the MIC2548. The breaker causes the output to latch off if the device enters thermal shutdown. The output can be reset by toggling the enable input. This feature prevents thermal oscillation, reducing current consumption during a fault.
"With other adjustable current-limit switches, fault current can actually increase during a short-circuit condition," said Micrel Product Marketing Manager Kris Jones. "The MIC2544 and MIC2548 employ foldback current limiting, which lowers the output current during a short-circuit fault. This feature, combined with the circuit-breaker function of the MIC2548, helps to preserve battery life in portable systems."
In quantities of 1,000, the MIC2544-1/-2BM and MIC2548-1/-2BM (eight-pin SOP packages) are priced at $1.24 each, and the MIC2544-1/-2BMM and MIC2548-1/-2BMM (eight-pin MSOP packages) are priced at $1.38 each.
