60A e-fuse occupies 5×4.5mm and works across 4.5-16V

Texas Instruments has created an 60A electronic fuse for system protection and power management (right), and a 50A version with added PMBus control.

Called TPS25985x, the 60A device “provides multiple protection modes using very few external components and is a robust defence against overloads, short-circuits and excessive inrush current”, according to the company.

Inside is a 0.59mΩ switch, and the package and its footprint (below) have been optimised for a low-resistance interface with the PCB.

Tripping under short-circuit conditions is <200ns and output slew rate can be set by an external capacitor. An adjustable over-current blanking timer accommodates transient peaks (up to 80A) without tripping the e-fuse circuit.

There are two variants of this chip: after the part shuts down due to a circuit-breaker fault, TPS259850 stays latched off, while TPS259851 re-starts automatically after a fixed delay.

Rated operation is over 4.5 – 16V, with a 20V abs max on the input. Safe-operating-area is specified as 12W√s.

Its analogue load current monitoring has 500kHz bandwidth and it ±1.4% accurate.

At the same time, TI announced a 50A related device in the same package, TPS25990, that includes a PMBus interface to allow a host microcontroller to monitor, control and configure parameters in real-time – they can also be stored in non-volatile configuration memory for stand-alone use. Black-box fault recording is included to assist field failure debug.

TPS25990 has a 0.79mΩ (typ) mosfet and is rated for 60A peak. SOA is different from the ..85 at 8W√s, and current monitoring accuracy is 2.1%. Trip response is in 280ns, and in this part a register setting decides if it latches-off or re-starts automatically after circuit-breaking.

Applications are foreseen in server motherboards, add-on cards, graphics cards, accelerator cards, enterprise switches and routers.

A TPS25985x evaluation module (TPS25985EVM, right) is available