AI & Data Centers

Data-centre power density keeps climbing — a rack has gone from tens of kilowatts to a hundred or more. Whether current is measured accurately at every stage of the power path determines whether supply modules can share current evenly, protect against over-current and optimise efficiency. And as cooling shifts from air to liquid, pump and valve drive becomes the new critical link.

End-to-end current monitoring.From utility input, UPS and PDU down to the server 12V / 48V bus and the VRM input of CPUs and GPUs, isolated current sensing is required throughout. RJMICRO linear and differential Hall current sensors cover tens to hundreds of amperes of DC and AC current, outputting an analogue signal proportional to current for module current sharing, over-current protection and system power metering.

Thermal management: 12V and 48V fan drive.Server fans are migrating from 12V to 48V to cut I²R loss and busbar cost. RJMICRO smart fan driver ICs integrate Hall commutation logic and the power stage, support both 12V and 48V rails, and provide closed-loop speed control, soft start, stall protection and tachometer feedback (FG / RD) for high-density racks.

Pump and valve drive for liquid cooling.Circulation pumps, proportional valves and quick-disconnect valves in a liquid-cooling CDU all need motor drive and position feedback. The motor control SoC drives the BLDC pumps and valves, 3D position Hall sensors read valve opening, and Hall latches sense flow-meter impellers and pump speed — a complete liquid-cooling actuator solution.

Server PSUs and rack power distribution.Current at every stage of a server PSU, from PFC to LLC, the branch currents of a smart rack PDU, and the charge/discharge current of a BBU all have to be measured with isolation inside a very limited board area. Linear Hall current sensors need no shunt resistor and add no height, which suits these dense layouts; the same applies to bus and branch current monitoring in 48V DC architectures such as OCP ORV3.