Power Delivery Passives Are Now Performance-Defining Parts

The Nvidia GB300 NVL72 rack pulls around 142 kW from its power shelves, and between that supply and the 72 Blackwell Ultra GPUs sit tens of thousands of multilayer ceramic capacitors (MLCCs) smoothing fast load swings. Depending on the platform, a fully populated GPU rack can contain hundreds of thousands of MLCCs for power filtering and decoupling, with a single accelerator board carrying tens of thousands. Meanwhile, Rubin-class racks expected in 2027 are targeting ~600 kW and 576 GPUs.

The transportation sector faces a similar situation. An EV contains 10,000 to 18,000 MLCCs, three to five times as many as a conventional vehicle, and 800 V powertrain platforms are pushing those MLCCs into higher voltage classes. 

Vertical power delivery (VPD) moves voltage regulator modules to the backside of the PCB, directly under the processor, putting passives on the critical path for transient response. For future megawatt-class AI racks, 800 V DC architectures are emerging alongside existing 48 V distribution approaches to reduce conversion stages, conductor mass, and power-delivery losses. 

We’ll now take a look at five passive categories that have become performance-defining: MLCCs, polymer and hybrid capacitors, high-current inductors, ferrites, and shunts. 

Key Takeaways

• AI server power density, vertical power delivery, EVs, and faster switching frequencies have pushed passives from a supporting role to performance-defining components.
• Real-world MLCC behavior under operating bias and temperature determines whether a rail meets spec. Datasheets don’t show the whole picture.
• Polymer and hybrid capacitors now handle many bulk decoupling use cases that aluminum electrolytics struggle to fill at modern switching frequencies.
• High-current inductors, ferrites, and shunts are taking on new responsibilities as PDN budgets tighten, layouts grow denser, voltages climb, and telemetry is integrated.

1. MLCCs: Operating Behavior Is the New Spec

A compact 10 µF, 25 V X7R MLCC can look like a routine decoupling part on a datasheet. Put 12 V of DC bias across it on a hot board, and effective capacitance drops to between 2 and 6 µF, losing 40 to 80 percent of nominal value, depending on package size, construction, and operating conditions. This behavior has become a first-order constraint on the number of parts a power delivery network (PDN) needs.

The same Class 2 dielectrics that give MLCCs their volumetric efficiency also exhibit piezoelectric behavior. At higher switching frequencies and capacitor counts, the resulting audible vibration (the “singing capacitor” problem) has prompted manufacturers to address acoustic noise and board-flex stress with package and termination changes, including soft-termination and metal-frame designs.

Recent product announcements address these challenges. Samsung Electro-Mechanics extended its C0G/X8G line to 1500 V in April 2026 for 800 V EV inverter systems and snubber applications. In the same month, Murata began mass production of automotive MLCCs that deliver 100 µF in a 1206 package, previously a 1210-only spec, cutting PCB area 36 percent, alongside a 0201 part with the highest capacitance yet announced at 4 V DC, both targeting ADAS and in-vehicle power rails. 

As of mid 2026, high-capacitance parts in 1206 and 1210 cases were experiencing 20-week lead times in some product lines, and Tier 1 automotive suppliers are locking up AEC-Q200 allocations through long-term agreements in response. The demand is driving up prices: Murata announced a 15 to 35 percent price hike on AI server and automotive-grade MLCCs effective April 1, 2026, with ferrite bead and inductor prices also climbing.

2. Polymer and Hybrid Capacitors: The Bulk Decoupling Layer

The bulk decoupling tier is under pressure on today’s boards. Aluminum electrolytics carry the capacitance density needed for low-frequency rail support, but their equivalent series resistance (ESR), life, and dry-out characteristics no longer hold up at the temperatures and ripple currents typical of AI server voltage regulator modules (VRMs) or 800 V EV powertrains. 

MLCCs handle high-frequency decoupling well, but their per-package capacitance runs out before bulk requirements are met, even before DC bias derating. Polymer capacitors and hybrid aluminum electrolytic capacitors have moved into the resulting space and now anchor the low-frequency tier of most modern PDN designs.

Products from Nichicon and Panasonic illustrate the trend. Nichicon’s GXC series is rated for 4,000 hours at 135 °C, with ripple current capacity required for ADAS modules and EV electronic control units. Panasonic's EEH-ZL series raised capacitance by up to 170 percent over the prior generation while maintaining 135 °C operation, bringing high-capacitance hybrid reliability into the temperature range where aluminum electrolytics fall short. 

Two-tier PDN designs are now the default for high-current rails: polymer bulk caps anchor the low-frequency tier up to a few hundred kHz, with MLCC banks handling high-frequency decoupling above that range. The handoff between tiers is where anti-resonance peaks form, and where engineers spend time tuning to avoid the impedance spikes that cause transient voltage droop.

A polymer or hybrid cap still needs to be chosen based on value, voltage, and footprint, but life at the operating temperature, ripple current rating at the actual switching frequency, ESR across the band of interest, and behavior under reverse-voltage transients all influence the decision.

3. High-Current Inductors: The Backbone of VPD

With VRMs sitting under the processor, the inductor’s profile, saturation behavior, and ripple current rating are now on the critical path for AI accelerator power integrity. Trans-inductor voltage regulator (TLVR) and coupled-inductor topologies are redefining what a power inductor needs to do: small transient inductance for fast load steps and larger steady-state inductance for ripple smoothing.

Infineon’s TDM24745T TLVR module hits 320 A peak in a 9 x 10 x 5 mm package, and its TDM2454xx modules reach 280 A at 2.0 A/mm² density. Empower’s Crescendo platform pushes more than 3,000 A through the PCB vertically by integrating air-core inductors with the regulator silicon.

The automotive sector runs into the same selection challenges, but at different operating points. Inductors in 48 V mild-hybrid converters, onboard chargers, and DC-DC stages between the traction battery and the low-voltage net all depend on hard versus soft saturation behavior, peak versus RMS current rating, and thermal derating across the operating envelope.

4. Ferrites: Quiet Workhorses Under Pressure

Ferrite beads still handle high-frequency noise control on supply rails, but dense PDN designs and faster switching frequencies make DC bias derating and placement decisions less forgiving. Analog Devices AN-1368 describes the trap that catches engineers most often: DC bias above 20 percent of rated current can collapse the effective bead impedance well below the datasheet value.

Resonance with adjacent decoupling capacitors is another common error that affects both AI accelerator boards and automotive ECUs as switching frequencies climb. Pricing pressure has hit this category too: due to rising silver costs, suppliers are raising prices across their ferrite product lines, while automotive-qualified parts are seeing the longest lead-time extensions.

5. Shunts: Sensing Becomes a System-Level Function

EV battery management systems can run hundreds of measurement points feeding protection, telemetry, and efficiency control loops, with the shunt as the front end. AI server power management applies the same pattern across thousands of points per rack at higher currents. 

At sub-milliohm values, where the sense voltage is only tens of millivolts at full scale, the temperature coefficient of resistance (TCR), four-terminal Kelvin construction, parasitic inductance, and Seebeck error are all relevant. Manganin and Cu-Mn alloys, electron-beam-welded copper designs, and Kelvin-pad layouts have become standard for high-power current sensing in both segments, with precision shunts replacing Hall-effect approaches in motor drives and onboard chargers for size, cost, and bandwidth reasons.

From Trends to Spec Decisions

The architectural shifts underway mean that operating behavior (including bias, temperature, ripple, and transient response) decides which qualified part fits a given rail. For the qualification angle on these components, see Standards for High-Reliability Passive Components. 

For an in-depth look at how to spec, see What to Spec for Power Delivery Passives, which walks through capacitance by frequency band, ESR and ripple limits, inductor saturation and core loss, ferrite impedance curves, shunt parasitics, and derating rules across passive classes.

Frequently Asked Questions About Power Delivery Passives in Modern PDNs

Why are passive components now considered performance-defining in power delivery networks (PDNs)?

Passive components directly determine transient response, stability, and efficiency in high-density systems. In AI servers, EVs, and VPD architectures, voltage droop, noise, and thermal limits are now constrained by real component behavior (not just controller design) making passives critical to meeting specs. 

How does DC bias affect MLCC performance in real designs?

DC bias can reduce effective capacitance by 40–80% in Class 2 MLCCs, especially under high voltage and temperature. This derating impacts decoupling strategy, often requiring more capacitors or alternative bulk solutions to maintain impedance targets and rail stability. 

When should engineers choose polymer or hybrid capacitors over MLCCs or electrolytics?

Polymer and hybrid capacitors are preferred for bulk decoupling at lower frequencies where MLCC capacitance is insufficient and aluminum electrolytics cannot handle ripple current or temperature. They provide lower ESR, better reliability, and higher performance in modern VRM and EV environments. 

What are the key selection risks for inductors, ferrites, and shunts in high-power systems?

Common pitfalls include inductor saturation under peak load, ferrite impedance collapse under DC bias, and shunt inaccuracies due to thermal drift and parasitics. Correct selection requires evaluating real operating conditions (current, temperature, frequency, and layout) not just datasheet values.