A highly integrated family of -70V hot-swap power controllers designed especially for telecom switch applications is now available from Micrel Semiconductor.
Manufactured in 20-pin TSSOP and thermally-enhanced TSSOP packages, the MIC2596 and MIC2597 incorporate two completely independent -70V channels. Each channel integrates a high-voltage MOSFET with adjustable current limiting. This combination reduces board space and allows the designer to optimize the design without compromising performance.
System reliability is increased by on-chip overcurrent and overtemperature shutdown capabilities which provide robust short-circuit protection. The two channels are thermally isolated so that a fault in one channel does not affect the other. Additionally, On/Off control and fault status signals are logic-compatible, eliminating the need for extra buffer and translation circuits.
In addition, the MIC2596 and MIC2597 can detect open-load conditions when a cable or line card is removed. The two devices differ only in the way they handle overcurrent conditions. The MIC2596 incorporates an auto-retry feature that will continuously attempt to restart the load in the event of a fault condition. The MIC2597 operates as a circuit breaker, latching off in the event of a fault condition.
At a nominal -48 V the devices can provide over 15 W per channel with the standard TSSOP package (BTS) and more than 30 W per channel with the exposed pad TSSOP package (BTSe.)