The precision dual level current limit enables legacy Power Sourcing Equipment (PSE) with limited current sourcing capability to power up the device while also allowing the device to draw full power from custom PSEs that exceed the limit of the existing standard. The LTC4264 is capable of handling 750mA with the lowest on-resistance (0.55 Ohm typ, 0.8 Ohm max) Hot Swap™ MOSFET on the market. The ultra-low FET on-resistance minimizes power wasted by device heating and improves overall efficiency. Additionally, the user has the option to disable the normal operating current limit and to increase the maximum current limit to approximately 1.4A.
The LTC4264 features both active-high and active-low power good signaling for simplified interface to any DC/DC converter. The part includes an onboard 25Kohm signature resistor, precision undervoltage lockout (UVLO) and thermal overload protection. The signature resistor can be disabled so that the device is not recognized or powered by the PSE in order to provide a seamless interface for an external wall adapter or other auxiliary power options.
The LTC4264 has the flexibility to support applications that meet the emerging IEEE 802.3at standard, as well as proprietary high power applications. Specified over the full commercial and industrial temperature range, the LTC4264 is offered in a thermally enhanced 12-pin 4mm x 3mm DFN package for superior high current performance. Pricing begins at $1.80 each for 1,000-piece quantities.
