TI Launches 800 V Isolated Hot-Swap Controller with Integrated PMBus Telemetry

Texas Instruments has introduced the LMI800PS, an isolated hot-swap controller for ±400 V and 800 V power distribution in high-voltage data center systems.

The new device brings functions that would otherwise require five ICs into a single high-density package, combining inrush-current control, power-path protection, an isolated bias supply and PMBus telemetry. TI says the integration reduces board area by more than 60%.

The LMI800PS is designed for systems where individual loads need to be connected to or isolated from a shared high-voltage bus without disturbing the rest of the power path. TI is targeting emerging 800 VDC server and rack architectures, where higher system voltages place more emphasis on safe power insertion, fault isolation and reinforced isolation between control and power domains.

Replacing a Five-IC Hot-Swap Stage

In a high-voltage rack, bringing a load onto the bus means controlling the initial inrush current rather than simply making a direct connection. A fault also needs to be isolated quickly enough that one load does not affect the rest of the shared power system.

The LMI800PS brings those functions into one device. It supports both ±400 V and 800 V distribution and provides inrush-current and power-path protection for the high-voltage input stage.

TI says the device replaces a discrete implementation requiring five ICs, with the isolated bias supply and PMBus telemetry now included alongside the hot-swap controller itself. The reduction in supporting circuitry is what allows TI to claim a board-area saving of more than 60%.

The device also provides 5 kVrms reinforced isolation and more than 8 mm creepage, addressing the physical isolation requirements that come with moving hot-swap control into higher-voltage power architectures.

Rather than treating the controller as a separate protection block around the edge of the design, TI is positioning it as part of the main rack-level power path. A load can be inserted safely, monitored while operating and isolated when a fault occurs without disrupting the shared bus.

Monitoring the Power Path Through PMBus

The other part of the LMI800PS story is telemetry.

Integrated PMBus support gives the system access to power-path information without adding a separate monitoring device. Combined with the isolated bias supply, this reduces the number of components needed around the protection stage while still providing the visibility required for remote system management.

That matters particularly in large server installations where high-voltage distribution is being used to move more power through the rack before stepping down closer to the compute hardware. TI is showing the LMI800PS alongside 800 V-to-12 V and 800 V-to-6 V DC/DC converter solutions as part of its wider 800 VDC power architecture.

The controller is also intended to stop a failure at one load from propagating onto the shared bus. TI describes the LMI800PS as providing safe power insertion and fast fault isolation, giving designers a single device for controlling how loads enter and leave the high-voltage power path.

The LMI800PS was introduced alongside two other new data center devices from TI: the ADC34DSO75, a 3 GSPS ADC for nanosecond-level power-rail monitoring, and the LMK6B BAW oscillator for high-speed networking. For the LMI800PS, however, the main change is the consolidation of isolation, bias, telemetry and hot-swap protection into one device for ±400 V and 800 V distribution systems.

Learn more and read the original announcement at ti.com.

Technology Overview

The TI LMI800PS is an isolated hot-swap controller for ±400 V and 800 V power distribution. It combines inrush-current control, power-path protection, an isolated bias supply and PMBus telemetry in a single device, with 5 kVrms reinforced isolation and more than 8 mm creepage.

FAQs

What does the TI LMI800PS replace?

TI says the device replaces a discrete hot-swap implementation requiring five ICs by integrating the controller, isolated bias and telemetry functions into a single package.

What power architectures does the LMI800PS support?

The controller supports both ±400 V and 800 V power distribution for high-voltage rack and server systems.

What isolation does the LMI800PS provide?

TI specifies 5 kVrms reinforced isolation and more than 8 mm creepage.