Current Sensing in Data Centers

Enabling Efficiency, Reliability and Scalability in Data Centers

Data centers are undergoing a profound transformation driven by the rapid growth of artificial intelligence, cloud computing, and digital services. As computing power increases, so does the demand for energy, pushing existing infrastructures to their limits and forcing a complete rethinking of how power is generated, distributed, and managed.

From traditional AC-based systems to emerging DC architectures, data centers are evolving toward more efficient, scalable, and high-density designs. In this context, accurate and reliable current measurement has become a cornerstone of performance, safety, and energy optimization.

LEM supports this transformation by providing advanced current sensing solutions across the entire data center power chain, from grid infrastructure to server racks, helping operators improve efficiency, ensure uptime, and prepare for next-generation architectures.

AC-Based Data Centers (Today’s Standard)

AC-based architectures remain the dominant design in today’s data centers. Power is delivered from the grid, transformed, and distributed across multiple layers before reaching IT equipment.

A typical architecture includes:

grid infrastructure (MV/LV switchgear and transformers)
uninterruptible power supply (UPS) systems
AC power distribution units (PDUs)
server-level power conversion (AC/DC, DC/DC)
cooling and HVAC systems

Each of these stages relies on dedicated power conversion and distribution equipment, forming a complex chain from grid to chip.

While widely deployed and reliable, AC-based architectures present several limitations:

Multiple conversion stages with cumulative efficiency losses
Limited visibility at system level making optimizations difficult
Increasing complexity, especially with growing redundancy requirements
Scaling constraints, driven by rising rack density and AI workloads

As data centers scale toward higher power levels and densities, improving efficiency and monitoring across these architectures becomes critical.

Where LEM adds value across AC-based data center applications

Accurate current measurement is required across the entire AC power chain to ensure performance, safety, and reliability.

LEM solutions are deployed at each key level:

Data Center Segment	Key Functions	Measurement Needs
Grid Infrastructure	MV/LV conversion, power input monitoring	Accurate AC current measurement, high isolation
Backup Power (UPS, Batteries)	Energy storage, backup supply continuity	High-accuracy AC/DC sensing, battery monitoring
Power Distribution (PDU, RPP)	Power routing, branch circuit monitoring	Load monitoring, compact sensing solutions
Power Conversion (PSU, AC/DC, DC/DC)	Voltage conversion, power regulation	High-bandwidth current sensing, fast switching control
Cooling & HVAC	Thermal management (fans, pumps, compressors)	Motor control, variable frequency drives

LEM products for AC Data Centers

With one of the industry’s broadest current sensing portfolios, LEM supports AC data center applications across the entire power chain, from grid infrastructure and backup power to power distribution, conversion, and cooling systems.

	Grid infrastructure			Backup Power			Power distribution			Power conversion			HVAC
Product Series	ITC	ART	HAZ	HO	HLSR	LAH	ARU	AP	AK	GXM	HAT	HASS	GO	HAX	LF
Bandwidth	27kHz - 82kHz	0,05kHz - 500kHz	3kHz	100kHz - 350kHz	90kHz - 450kHz	100kHz - 200 kHz	0,05kHz - 500kHz	0,03kHz - 30kHz	0,02kHz - 0,1kHz	320 kHz	25kHz	240kHz	300 kHz	25 kHz	100kHz - 200kHz
Consumption	70mA	-	20mA 10V	25mA	19mA	10mA - 19mA	-	4 - 20mA 0 - 5V	4 - 20mA 0 - 10V	Vref +/- 1.65 V Vref +/- 2.5 V	4V	2.5 +/- 0.625 V	20mA	4V	33mA - 49mA
Current range Max	3000A - 6000A	1000 A	2000A - 20000A	20A - 625A	25A - 300A	55A - 226A	1000 A	50A - 400A	5A - 400A	50A - 200A	500A - 2500A	150A - 1100A	10A - 75A	1500 - 7500 A	200A - 3400A
Supply Voltage	24V	-	15V - 15V	5V	3,3V - 5V	12V - 15V	-	12V - 24V 24V - 24V	24V - 24V	3,3V - 3,3V 5V - 5V	15V - 15V	5V - 5V	3.3V - 5V	12 V - 12V 15V - 15V	12V - 24V
Mounting	Panel	Busbar	Panel	PCB, Panel	PCB	PCB	Busbar	Panel, DIN Rail	Panel, DIN Rail	SOIC 10	Panel	Panel	SOIC 16	Panel	Panel
Output	Current	Voltage	Current, Voltage	Voltage	Voltage	Current	Voltage	Current, Voltage	Current, Voltage	Analog	Voltage	Voltage	Analog	Voltage	Current
Accuracy	0,05%	0,5%	1%	1% - 1,35%	1%	0,3% - 0,41%	0,5%	1%	1%	2%	1%	1%	1,3% - 3%	1%	0,2% - 0,6%

Partial DC Data Centers (Emerging Architectures)

Partial DC architectures represent a hybrid approach, combining traditional AC distribution with increasing use of DC at rack or subsystem level.

In this model:

AC power is still used at facility level
DC distribution is introduced closer to the load (rack, row, or IT level)
New conversion stages (e.g. HVDC, IBC) replace part of the AC/DC chain

Typical elements include:

AC grid infrastructure and UPS systems
DC buses (e.g. 48V or higher voltage DC such as 800V)
intermediate bus converters (IBC) and point-of-load (PoL) converters

This architecture reduces the number of conversion steps between grid and chip, simplifying the overall power path. Compared to traditional AC-based systems, partial DC architectures provide significant advantages:

Reduced conversion stages offering higher overall efficiency
Lower current levels at higher voltages: reduced I²R losses
Higher power density, providing better support for AI workloads
Improved scalability, delivering simpler distribution at high power levels

For example, high-voltage DC distribution (such as ~800V DC) allows lower current for the same power, reduced cabling complexity and improved thermal performance.

These benefits make partial DC architectures particularly relevant for next-generation AI data centers, where rack power can reach extremely high levels.

Where LEM adds value across Partial DC Data Centers

Data Center Segment	Key Functions	Measurement Needs
Grid Infrastructure	AC supply, MV/LV conversion	Accurate AC measurement, isolation
Backup Power (UPS, BBU, BESS)	Distributed energy storage	High-precision DC sensing, fast response
Power Distribution (DC buses)	DC power routing, protection	DC current monitoring, fault detection
Power Conversion (HVDC, IBC, PoL)	High-efficiency conversion	High-bandwidth sensing, fast switching control
Cooling & HVAC	High-efficiency thermal systems	Motor control, DC drive monitoring

LEM products for Partial DC Data Centers

As data centers move toward hybrid AC/DC designs, LEM provides a versatile portfolio of current sensing solutions to address the new performance, protection, and efficiency requirements of partial DC architectures.

	Grid infrastructure			Backup Power			Power distribution			Power conversion			HVAC
Product Series	ITL	ART	AK	HOYS	LAH	HAX	GXS	ARU	ATO	GXM	HASS	HLSR	HMSR	GO	LF
Bandwidth	100kHz - 500kHz	0,05kHz - 500kHz	0,02kHz - 0,1kHz	180kHz	100kHz - 200 kHz	25 kHz	400kHz	0,05kHz - 500kHz	0,05kHz - 0,06kHz	320 kHz	240kHz	90kHz - 450kHz	300kHz	300 kHz	100kHz - 200kHz
Consumption	60mA - 130mA	-	4 - 20mA 0 - 10V	25mA	10mA - 19mA	4V	Vref +/- 2.5 V	-	4 - 125mA 0,333V	Vref +/- 1.65 V Vref +/- 2.5 V	2.5 +/- 0.625 V	19mA	20mA	20mA	33mA - 49mA
Current range Max	12,5A - 1000A	1000 A	5A - 400A	250A - 1400A	55A - 226A	1500 - 7500 A	5A - 50A	1000 A	6A - 176,7A	50A - 200A	150A - 1100A	25A - 300A	15A - 75A	10A - 75A	200A - 3400A
Supply Voltage	15V	-	24V - 24V	3,3V - 5V	12V - 15V	12 V - 12V 15V - 15V	3,3V - 3,3V 5V - 5V	-	-	3,3V - 3,3V 5V - 5V	5V - 5V	3,3V - 5V	3,3V - 5V	3.3V - 5V	12V - 24V
Mounting	PCB, Panel	Busbar	Panel, DIN Rail	Panel	PCB	Panel	SOIC 8	Busbar	Busbar, DIN Rail	SOIC 10	Panel	PCB	SOIC 10	SOIC 16	Panel
Output	Current	Voltage	Current, Voltage	Voltage	Current	Voltage	Analog	Voltage	Current, Voltage	Analog	Voltage	Voltage	Analog	Analog	Current
Accuracy	0,00115% - 0,0509%	0,5%	1%	1% - 1,25%	0,3% - 0,41%	1%	2%	0,5%	1% - 1,5%	2%	1%	1%	1% - 3%	1,3% - 3%	0,2% - 0,6%

A key transition toward full DC architectures

Partial DC data centers represent a critical transition between legacy AC systems and future fully DC infrastructures.

They allow operators to improve efficiency step by step, validate emerging technologies, and prepare for large-scale DC deployment.

At the same time, current sensing becomes even more important, as these architectures operate at higher voltages, rely on fewer but more sensitive conversion stages, and demand more advanced control and protection mechanisms.

LEM’s portfolio is already aligned with these evolving requirements, enabling customers to deploy hybrid architectures today while preparing for full DC infrastructures tomorrow.

Preparing for the Future: Full DC Distribution

As data centers scale to support AI-driven workloads, traditional architectures are reaching their limits. To improve efficiency and simplify power distribution, the industry is exploring full DC architectures, where power flows continuously in DC from the grid to the chip.

Driving efficiency at scale

By reducing the number of conversion stages, full DC distribution can lower energy losses, simplify power paths and improve overall system efficiency.

It also enables better integration with battery storage and renewable energy sources, key elements for future large-scale data centers.

Despite its potential, full DC remains a long-term evolution. Challenges such as DC protection, safety, and ecosystem maturity still need to be addressed before large-scale adoption.

LEM is already preparing for this transition: Products for Full DC Data Centers

Full DC architectures require high-accuracy, high-bandwidth DC current sensing to ensure safe and efficient operation.

LEM is already developing solutions aligned with these needs, including:

integrated current sensors (ICS) for fast-switching converters
high-voltage DC sensing technologies
compact and high-performance measurement solutions

This positions LEM to support the transition toward full DC data centers, helping customers move from today’s architectures to future-ready infrastructures.

	Solid State Transformer			Backup Power			Power distribution			Power conversion			HVAC
Product Series	HOB	FRS	HTA	HOYS	LAH	HAX	GXS	DVL	DVC	GXM	HASS	HLSR	HMSR	GO	LF
Bandwidth	1000kHz	1000kHz	50khz	180kHz	100kHz - 200kHz	25kHz	400kHz	14kHz	20kHz - 30kHz	320 kHz	240kHz	90kHz - 450kHz	300kHz	300 kHz	100kHz - 200kHz
Consumption	22mA - 24mA	80mA - 140mA	25mA	25mA	10mA - 19mA	4V	Vref +/- 2.5 V	25mA	17mA - 20mA	Vref +/- 1.65 V Vref +/- 2.5 V	2.5 +/- 0.625 V	19mA	20mA	20mA	33mA - 49mA
Current range Max	125A - 250A	9000A	300A - 1000A	250A - 1400A	55A - 226A	1500 - 7500 A	5A - 50A	75V - 3000V	1000V - 1500V	50A - 200A	150A - 1100A	25A - 300A	15A - 75A	10A - 75A	200A - 3400A
Supply Voltage	3,3V - 5V	12V - 24V	15V	3,3V - 5V	12V - 15V	12 V - 12V 15V - 15V	3,3V - 3,3V 5V - 5V	15V - 24V	5V - 24V	3,3V - 3,3V 5V - 5V	5V - 5V	3,3V - 5V	3,3V - 5V	3.3V - 5V	12V - 24V
Mounting	PCB	Busbar	Panel	Panel	PCB	Panel	SOIC 8	Panel	DIN Rail, Panel	SOIC 10	Panel	PCB	SOIC 10	SOIC 16	Panel
Output	Voltage	Voltage / Current	Voltage	Voltage	Current	Voltage	Analog	Current	Current	Analog	Voltage	Voltage	Analog	Analog	Current
Accuracy	1.2% - 1.45%	0.5%	1%	1% - 1,25%	0,3% - 0,41%	1%	2%	0.5%	1.7%	2%	1%	1%	1% - 3%	1,3% - 3%	0,2% - 0,6%

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