The MAX5921/MAX5939 hot-swap controllers allow a circuit card to be safely hot plugged into a live backplane. The MAX5921/MAX5939 operate from -20V to -80V and are well suited for -48V power systems. These devices are pin compatible with both the LT1640 and LT4250 and provide improved features over these devices. The MAX5921/MAX5939 provide a controlled turn-on to circuit cards preventing damage to board connectors, board components, and preventing glitches on the power-supply rail. The MAX5921/MAX5939 provide undervoltage, overvoltage, and overcurrent protection. These devices ensure that the input voltage is stable and within tolerance before applying power to the load. Both the MAX5921 and MAX5939 protect a system against overcurrent and short-circuit conditions by turning off the external MOSFET in the event of a fault condition. The MAX5921/MAX5939 protect against input voltage steps by limiting the load current to a safe level without turning off power to the load. The device features an open-drain power-good status output, PWRGD or PWRGD for enabling downstream converters (see Selector Guide). A built-in thermal shutdown feature is also included to protect the external MOSFET in case of overheating. The MAX5939 features a latched fault output. The MAX5921 contains built-in autoretry circuitry after a fault condition. The MAX5921/MAX5939 are available in an 8-pin SO package and operate in the extended -40°C to +85°C temperature range.
The MAX5921/MAX5939 are hot-swap controllers designed to allow circuit cards to be safely hot-plugged into a live backplane, specifically suited for -48V power systems. These devices provide controlled turn-on sequences to prevent damage to board connectors and components while ensuring input voltage stability before applying power to the load.
Key features include protection against overcurrent, short-circuit conditions, undervoltage, and overvoltage. The MAX5921 includes built-in autoretry circuitry after a fault condition, whereas the MAX5939 features a latched fault output. Both devices operate from -20V to -80V and are available in an 8-pin SO package.
| Operating Input Voltage Range | -20V to -80V |
|---|---|
| Operating Temperature Range | -40°C to +85°C |
| Package Type | 8-pin SO |
The MAX5921/MAX5939 operate from -20V to -80V and are well suited for -48V power systems.
Yes, they are pin compatible with both the LT1640 and LT4250.