eFuse breaks through to meet demand in server applications
Claimed to be the first eFuse suitable for server applications, the AOZ18101DI series of 5A eFuses have been launched by Alpha and Omega Semiconductor (AOS).
They have what is claimed to be an industry-leading performance with low 20 mOhm on-resistance for sub-power rails in server applications. The AOZ18101DI series of 5A eFuses are supplied in a compact 3.0 x 3.0mm DFN package. They use AOS’s co-packaging technology, which combines the IC with protection features and the company’s latest safe operating area SOA) trench MOSFET. The eFuses offer low RDS(ON) of 20 mOhm and the back-to-back MOSFETs isolate the load from the input bus when the eFuse is off.
High-reliability requirements for server products mean that all critical power rails are monitored and protected by an eFuse device to protect the main power bus from interruption due to abnormal load under fault conditions. The eFuse continuously monitors the current flowing through the power switch. If the current is higher than the set limit, the switch will limit the current to the maximum allowed. If the high current load persists, the switch will eventually turn off, protecting downstream loads from damage, thus acting as a fuse.
The AOZ18101DI-01 and AOZ18101DI-02 integrate true reverse current blocking (TRCB) for the fault conditions that the power rail at VOUT is higher than the main bus at VIN, allowing no reverse current. Control for the external blocking FET is also available for designs already in production, these are drop-in replacements for existing eFuse products requiring external FETs to implement the TRCB feature. For loads with high inductive kickback such as hard disc drive, and server fans, the AOZ18101DI-03 and AOZ18101DI-04 have this TRCB feature disabled to avoid shut down of the input power bus due to a reverse current.
All devices feature startup SOA management and programmable over-current protection, under-voltage lock-out, over-voltage clamp, thermal shutdown protection, programmable soft-start, start up SOA management. These features allow for glitch-free power-up of the system or hot plug into the 12V backplane, advised AOS.
“High-reliability systems such as servers and storage require input bus protection. Traditional designs use a hot-swap controller and an external discrete FET,” said Peter Cheng, Power IC Senior Marketing Director at AOS. This is making way, however for the more compact eFuse and Cheng added “AOS’s ability to combine TrenchFET technology with leading IC design enables compact, robust eFuse products”.
The AOZ18101DI series are immediately available in production quantities with a lead-time of 14 weeks.
