Analog Devices Inc./Maxim Integrated

The LTC4233 is an integrated solution for Hot Swap™applications that allows a board to be safely inserted and removed from a live backplane. The part integrates a Hot Swap controller, power MOSFET and current sense resistor in a single package for small form factor applications. The MOSFET Safe Operating Area is production tested and guaranteed for the stresses in Hot Swap applications.The LTC4233 provides separate inrush current control and an 11% accurate 11.2A current limit with output dependent foldback. The current limit threshold can be adjusted dynamically using the ISETpin. Additional features include a current monitor output that amplifies the sense resistor voltage for ground referenced current sensing and a MOSFET temperature monitor output. Thermal limit, overvoltage, undervoltage and power good monitoring are also provided. For a 20A pin compatible version see LTC4234.ApplicationsHigh Availability ServersSolid State DrivesIndustrialNetwork Routers and Switches

The LTC4236 offers ideal diode-OR and Hot Swap functions for two power rails by controlling external N-channel MOSFETs. MOSFETs acting as ideal diodes replace two high power Schottky diodes and the associated heat sinks, saving power and board area. A Hot Swap control MOSFET allows a board to be safely inserted and removed from a live backplane by limiting inrush current. The supply output is also protected against short-circuit faults with a fast acting foldback current limit and electronic circuit breaker.The LTC4236 regulates the forward voltage drop across the ideal diode MOSFETs to ensure smooth current transfer from one supply to the other without oscillation. The ideal diode MOSFETs turn on quickly to reduce the load voltage droop during supply switchover. If the input supply fails or is shorted, a fast turn-off minimizes reverse current transients.A current sense amplifier translates the voltage across the sense resistor to a ground referenced signal. The LTC4236 provides adjustable start-up delay, turn-on/-off control, and reports fault and power good status for the supply.ApplicationsRedundant Power SuppliesHigh Availability Systems and ServersTelecom and Network Infrastructure

The LTC4240 is a Hot Swap™controller that allows a board to be safely inserted and removed from a live CompactPCI bus slot. The LTC4240 has a built-in 2-wire I2C compatible interface to allow software control and monitoring of device function and power supply status. Two external N-channel transistors control the 3.3V and 5V supplies, while two internal switches control the –12V and 12V supplies. Electronic circuit breakers protect all four supplies against overcurrent faults. ThePWRGDoutput indicates when all of the supply voltages are within tolerance. The OFF/ONpin is used to cycle the board power or reset the circuit breaker. The I2C interface allows the user to turn the device off or on, setRESETOUT, turn on the status LED driver and ignore 12V, –12V faults. It also allows the user to read the status of theFAULT,RESETIN,RESETOUT,PWRGD, PRSNT1# and PRSNT2# pins. Under a fault condition, the I2C interface can also be used to determine which of the four supplies generated the fault. The LTC4240 is available in a 28-pin narrow SSOP package.ApplicationsHot Board Insertion into CompactPCI BusElectronic Circuit Breaker

The LTC4244/LTC4244-1 are Hot Swap™controllers that allow a board to be safely inserted into and removed from a CompactPCI™bus slot. External N-channel transistors control the 5V and 3.3V supplies while on-chip switches control the ±12V supplies. The 3.3V and 5V supplies can be ramped up at an adjustable rate. Electronic circuit breakers protect all four supplies against overcurrent faults. After the power-up cycle is complete, the TIMER pin capacitor serves as auxiliary VCCallowing the LTC4244/LTC4244-1 to function without interruption in the presence of voltage spikes on the 12VINsupply. ThePWRGDoutput indicates when all four supplies are within tolerance. The OFF/ONpin is used to cycle board power or reset the circuit breaker. The PRECHARGE output can be used to bias the bus I/O pins during card insertion and extraction. PCI_RST# is combined on-chip with HEALTHY# in order to generate LOCAL_PCI_RST#.ApplicationsHot Board Insertion into CompactPCI Bus

The LTC4246 contains eight switches, each with an independent circuit breaker function. It is particularly well suited for extremely space constrained designs. Each switch can operate completely autonomously or be arbitrarily grouped with other switches that will respond together to the fault of any single device within its group. Optionally, channel grouping may be extended to multiple LTC4246 devices by selecting the FIN# (fault input) pin as part of a channel group. A required bias supply between 2.5V to 5V allows the switches to independently operate from 13.2V down to 0V. The LTC4246 provides an SPI serial interface to enable, disable and configure the timing and current thresholds of each channel as well as provide status to each channel’s fault state.A common open-drain FAULT status output indicates if any switch has opened due to a circuit breaker event.ApplicationsATE Wafer Probe ElectronicsScope Probe ProtectionIndustrial ControlRelay Replacement