Hot Swap Controller Allows I2C Monitoring of Board-Level OperationHot Swap Controller Allows I2C Monitoring of Board-Level Operation

LECTRONICS: Linear Technology Corp. introduced the LTC®4280, a 2.9 to 15V Hot Swap^™ controller that features an onboard 8-bit ADC and I²C compatible interface. Integrated digital power monitoring enables sophisticated platform management in high-availability systems, measuring card voltages and currents, as well as recording past and present fault conditions. In such systems, careful monitoring of the health and integrity of the power distribution network is crucial. Information in the ADC registers can be queried via the I²C bus and then used to determine if a card is actually using its allocated power or operating abnormally. The LTC4280 allows an irregular card to be flagged for service before it fails, thereby improving system reliability.

The LTC4280 is suitable for a wide range of applications, including redundant supply 12V systems subject to line transients when supplies switch over. Board supply voltages and inrush current are ramped up at an adjustable rate. The LTC4280 has an adjustable circuit breaker filter time and a 26mV current limit to accommodate a wide variety of input line and output line transients. Undervoltage and overvoltage thresholds are also independently adjustable. The controller disconnects the load if it remains in current limit beyond the time-out delay specified and can be configured to latch off or auto-retry following the event. The LTC4280 has additional features to interrupt the host when a fault has occurred, notify when output power is good, detect insertion of a board and turn off the pass transistor if an external supply monitor fails to indicate power good within a timeout period.

The LTC4280 is offered in commercial and industrial versions, supporting operating temperature ranges from 0 to 70C and -40 to 85C, respectively. The LTC4280 is available in a RoHS-compliant 24-pin 4 x 5mm QFN package. Pricing starts at $3.95 each in 1,000 piece quantities and is now available in production quantities. The LTC4280 complements Linear Technology’s LTC4260 and LTC4261, positive and negative high voltage Hot Swap™ ^{controllers that also feature onboard ADCs and I2C interfaces.}

-Edited by Kelsey Anderson