What the -48V rating means for the BOM
The LM5068MM-2/NOPB is a hot swap controller designed for -48V telecom and datacom backplane applications. Its supply voltage range of -90V to -10V covers the standard -48V nominal rail with margin for transients and ring-trip voltages. It does not integrate the pass FET — the external N-channel MOSFET is selected by the designer based on the load current and thermal budget. This gives the BOM engineer control over the conduction loss and SOA for the specific line card. At 820 µA supply current, the controller's own draw is negligible against the load, but it sets the minimum bias requirement for the gate drive charge pump.
Programmable protection — what each feature governs
The controller integrates programmable circuit breaker, current limit, fault timeout, overvoltage protection (OVP), and undervoltage lockout (UVLO). These are set with external resistors and capacitors, not digital trim — the BOM engineer selects the RC values to match the card's inrush profile and the upstream breaker coordination. The auto-retry feature means the controller attempts to restart after a fault timeout, which is useful for a line card that should self-recover after a transient overload without a manual power cycle. The turn-on voltage threshold is also programmable.
Package, footprint, and temperature grade
Housed in an 8-VSSOP (also specified as 8-TSSOP / 8-MSOP with 0.118-inch, 3.00 mm width). The supplier device package is 8-VSSOP — the same footprint as the MSOP-8, but with a thinner body (1.1 mm max) that suits low-profile mezzanine cards. A base-station line card in a ventilated cabinet sees internal air temperatures around 85°C, leaving 20°C margin before the upper limit. Surface-mount only — the 8-VSSOP has a 0.65 mm pitch, which fan-outs cleanly on a 2-layer board if the copper pour under the exposed pad is connected to the negative rail.
For a new design, the active status means the part is supported for long-term production without a forced last-time-buy window.