Analog Devices Inc./Maxim Integrated

The LTC4283 negative voltage hot swap controller drives an external N-channel MOSFET to allow a board to be safely inserted and removed from a live backplane. The device features programmable current limit with foldback and independently adjustable inrush current to optimize the MOSFET safe operating area (SOA). The SOA timer limits MOSFET temperature rise for reliable protection against overstresses.An I2C interface and onboard gear-shift ADC allow monitoring of board current, voltage, power, energy, and fault status. An available single-wire broadcast mode simplifies the interface by eliminating two isolators. The included EEPROM provides black-box capturing and nonvolatile configuration of fault behavior.Additional features respond to input UV/OV, interrupt the host when a fault has occurred, notify when output power is good, detect insertion of a board, turn off the MOSFET if an external supply monitor fails to indicate power good within a timeout period, and auto-reboot after a programmable delay following a host commanded turn-off.APPLICATIONSTelecom Infrastructure–48V Distributed Power SystemsServers and Data CentersPower Monitors

The LTC4284 negative voltage hot swap controller drives external N-channel MOSFETs to allow a board to be safely inserted and removed from a live backplane. The dual-gate, multi-mode drivers optimize the MOSFET safe operating area (SOA) for a variety of power levels. The SOA timer limits MOSFET temperature rise for reliable protection against overstresses.An I2C interface and onboard gear-shift ADC allow monitoring of board current, voltage, power, energy, and fault status. An available single-wire broadcast mode simplifies the interface by eliminating two isolators. The included EEPROM provides black-box capturing and nonvolatile configuration of fault behavior.Additional features respond to input UV/OV, interrupt the host when a fault has occurred, notify when output power is good, detect insertion of a board, turn off the MOSFETs if an external supply monitor fails to indicate power good within a timeout period, and auto-reboot after a programmable delay following a host commanded turn-off.APPLICATIONSTelecom Infrastructure–48V Distributed Power SystemsServers and Data CentersPower Monitors

The LTC4286 is an integrated solution for hot-swap applications allowing a board to be safely inserted and removed from a live backplane. The circuit breaker timer protects against metal-oxide semiconductor field-effect transistor (MOSFET) overheating, enabling reliable protection against overstress.The SMBus 3.1 interface, PMBus command structure, and onboard analog-to-digital converter (ADC) with selectable averaging and speed allow monitoring of board current, voltage, power, temperature, and fault status.The LTC4286 has additional features to respond to input undervoltage (UV) and overvoltage (OV): interrupts the host when a fault occurs, notifies when output power is good, detects insertion of a board, and auto-reboot after a programmable delay following a host commanded turn off.APPLICATIONSHigh availability server backplane systems12 V/24 V/48 V/54 V Distributed power systemsIndustrial

The LTC4287 is an integrated solution for hot swap applications that allows a board to be safely inserted and removed from a live backplane. The dual-gate drivers coupled with configurable multimode startup sequencing and operation optimize the metal-oxide semiconductor field-effect transistor (MOSFET) safe operating area (SOA) for a variety of power levels. The circuit breaker timer limits the MOSFET temperature for reliable protection against overstress.The SMBus 3.1 interface, PMBus command structure, and onboard analog-to-digital converters (ADCs) with selectable resolution and speed allow monitoring of board current, voltage, power, energy, temperature, and fault status. An optional external, electrically erasable programmable read only memory (EEPROM) can be used for part configuration and provide BlackBox capturing of past fault conditions.The LTC4287 has additional features to respond to input undervoltages and overvoltages, to interrupt the host when a fault has occurred, to notify when the output power is good, to detect insertion of a board, to turn off the MOSFET if an external supply monitor fails to indicate power-good within a timeout period, and to auto reboot after a programmable delay following a host commanded turn-off.APPLICATIONSHigh availability server backplane systems12 V/24 V/48 V/54 V distributed power systemsIndustrial

The LTC4290/LTC4271 chipset is an 8-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3at Type 1 and Type 2 (high power) compliant Power over Ethernet (PoE) systems. Transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply resulting in significant BOM cost savings. The LTC4290/LTC4271 chipset delivers lowest-in-industry heat dissipation by utilizing low-RDS(ON)external MOSFETs and 0.25Ω sense resistors.Advanced power management features include per-port 12-bit current monitoring ADCs, DAC-programmable current limit, and versatile fast shut-down of preselected ports. Advanced power management host software is available under a no-cost license. PD discovery uses a proprietary dual-mode 4-point detection mechanism ensuring excellent immunity from false PD detection. Midspan PSEs are supported with 2-event classification and a 2 second backoff timer. The LTC4290/LTC4271 includes an I2C serial interface operable up to 1MHz.The LTC4290/LTC4271 is available in multiple power grades allowing delivered PD power up to 90W.ApplicationsPoE PSE Switches/RoutersPoE PSE Midspans

The LTC4291-1 /LTC4292chipset is a 4-port power sourcing equipment (PSE) controller designed for use in IEEE 802.3bt Type 3 and 4 compliant Power over Ethernet (PoE) systems. The LTC4291-1 / LTC4292 is designed to power compliant 802.3af, 802.3at, and 802.3bt PDs. The LTC4291-1 / LTC4292 chipset delivers lowest-in-industry heat dissipation by utilizing low RDS(ON)external MOSFETs and 0.15Ω sense resistance per power channel. A transformer-isolated communication protocol replaces expensive opto-couplers and complex isolated 3.3V supply, resulting in significant BOM cost savings.Advanced power management features include per-port 14-bit current monitoring, programmable current limit, and versatile fast shutdown of preselected ports. Advanced power management host software is available under a no-cost license. PD detection uses a proprietary multipoint detection mechanism ensuring excellent immunity from false PD identification. Autoclass and 5-event physical classification are supported. The LTC4291-1 / LTC4292 includes an I2C serial interface operable up to 1MHz. The LTC4291-1/LTC4292 is pin or I2C programmable to negotiate PD delivered power up to 71.3W.

The LTC4296-1 is an IEEE 802.3cg-compliant, five port, single-pair power over Ethernet (SPoE), power sourcing equipment (PSE) controller. SPoE simplifies system design and installation with standardized power and Ethernet data over a single-pair cable. The LTC4296-1 is designed for interoperability with 802.3cg powered devices (PDs) in 24 V or 54 V systems. The LTC4296-1 delivers power using external, low drain-to-source on resistance (RDS(ON)), N-channel metal-oxide semiconductor field-effect transistors (MOSFETs), which minimize voltage drop and ensure application ruggedness.High-side circuit breakers with foldback, analog current limit (ACL) provide controlled inrush and short-circuit protection. An optional low-side circuit breaker protects the negative output against backfeed faults, and ground faults in nonisolated applications. PD classification via the serial communication classification protocol (SCCP) and maintain full voltage signature (MFVS) ensure that the full operating voltage is only applied to the cable when a PD is present. The SWx pins disconnect port power snubbers during detection and classification. PD initiated sleep and wake-up are supported. The WAKEUP pin supports wake-up forwarding. Telemetry, status, and software control features are accessed via a serial peripheral interface (SPI) bus interface with packet error code (PEC) protection.The LTC4296-1 provides a versatile SPoE, PSE solution for 10BASE-T1L controllers and switches and can easily be integrated with the Analog Devices, Inc., 10BASE-T1L transceiver portfolio, such as the ADIN1100 (physical layer, PHY), ADIN1110 (MACPHY), and ADIN2111 (2-port switch).APPLICATIONSOperational technology (OT) systemsBuilding and factory automation systemsField instruments and switchesSecurity systemsTraffic control systems

The LTC4300 series hot swappable 2-wire bus buffers allow I/O card insertion into a live backplane without corruption of the data and clock busses. When the connection is made, the LTC4300-1/LTC4300-2 provide bidirectional buffering, keeping the backplane and card capacitances isolated. Rise-time accelerator circuitry* allows the use of weaker DC pull-up currents while still meeting rise-time requirements. During insertion, the SDA and SCL lines are precharged to 1V to minimize bus disturbances.The LTC4300-1 incorporates a CMOS threshold digital ENABLE input pin, which forces the part into a low current mode when driven to ground and sets normal operation when driven to VCC. It also includes an open drain READY output pin, which indicates that the backplane and card sides are connected together. The LTC4300-2 replaces the ENABLE pin with a dedicated supply voltage pin, VCC2, for the card side, providing level shifting between 3.3V and 5V systems. Both the backplane and card may be powered with supply voltages ranging from 2.7V to 5.5V, with no contraints on which supply voltage is higher. The LTC4300-2 also replaces the READY pin with a digital CMOS input pin, ACC, which enables and disables the rise-time accelerator currents.The LTC4300 is available in a small 8-pin MSOP package.*U.S. Patent No. 6,650,174ApplicationsHot Board InsertionServersCapacitance Buffer/Bus ExtenderDesktop Computer