TDK Capacitors: Advanced Ceramic Technology Complete Guide

If you’ve been designing with MLCCs for more than a few years, TDK is a name you’ve built into your BOMs hundreds of times — sometimes without thinking too hard about why. The honest reason is that TDK is one of the most technically advanced MLCC manufacturers on the planet. Their ceramic material science, dielectric formulations, and proprietary multilayer stacking processes are genuinely best-in-class for several key metrics. But the catalog is deep, and picking the wrong series for your application — or ignoring how TDK structures their capacitor families — wastes real design time.

This guide cuts through the catalog and gives you a practical engineering view of TDK’s ceramic MLCC lineup: how the commercial C series and automotive CGA series are organized, what the high-reliability CGJ series actually offers, where TDK’s high-voltage and high-temperature MLCCs fit against competing technologies, and which design tools from TDK’s technical support library are genuinely worth using.

Why TDK Dominates Advanced MLCC Technology

TDK was founded in 1935 specifically to commercialize ferrite materials — they invented the ceramic magnetic core that makes modern electronics possible. That foundational materials science capability carries directly into their MLCC dielectric formulations today. Their proprietary thin-layer ceramic technology allows them to push capacitance density higher and voltage ratings further than most competitors within identical case sizes.

TDK posted total sales of USD 14.6 billion in fiscal 2024 and employs approximately 101,000 people worldwide. Their capacitor products are marketed under the TDK and EPCOS brands, with a deep product engineering presence in automotive, industrial, and consumer electronics.

TDK’s C series commercial MLCCs use a monolithic structure where multilayer dielectrics and inner electrodes are stacked alternately, providing superior mechanical strength and high reliability. The series delivers outstanding frequency characteristics — low ESR and low ESL — owing to this simpler monolithic construction compared to other capacitor types. The capacitance range extends up to 100 µF, a territory that used to belong exclusively to aluminum electrolytic and tantalum capacitors.

TDK MLCC Series Overview: C (Commercial) vs CGA (Automotive)

TDK organizes their MLCC lineup into two primary product families: the C series for commercial applications and the CGA series for automotive applications. Within each family, products are further divided by voltage class, dielectric type, and special construction features like soft termination. Understanding this hierarchy is step one for efficient TDK catalog navigation.

Product Family	Grade	Qualification	Voltage Classes	Key Feature
C series	Commercial	Standard	General (4–50V), Mid (100–630V), High (1000–3000V), High Temp	Widest size and cap range, 01005 to 2220
CGA series	Automotive	AEC-Q200	General (up to 50V), Mid (up to 630V), High (to 1,250V), High Temp	Proven 30+ year automotive heritage
CGJ series	High Reliability	AEC-Q200 + extended life	General	Tamper-proof seal, Sigma Report, RFID option
CGA Soft Termination	Automotive	AEC-Q200	General	Conductive resin layer for flex crack resistance

The fundamental difference between C and CGA series comes down to qualification documentation and additional reliability verification, not a fundamentally different base construction. CGA parts are subjected to increased inspection protocols and qualify to AEC-Q200 with PPAP (Production Part Approval Process) available on request — the paperwork Tier 1 automotive suppliers and OEMs require.

TDK C Series: Commercial MLCC Deep Dive

## General Voltage C Series (4V to 50V)

The bread-and-butter TDK commercial MLCC. The C series covers case sizes from 01005 through 2220 with dielectrics including C0G, SL, X5R, X6S, X7R, X7S, and Y5V, voltage ratings from 4V to 50V, and capacitance values up to 100 µF. This is one of the widest size and dielectric ranges available from a single MLCC manufacturer.

One critical note for engineers new to TDK: TDK uses metric case size codes in their part numbers, not the EIA standard codes used by most other manufacturers. What TDK calls a “3” or “CGA3” is a 0603 in EIA. What they call “5” is 1206. This trips up a lot of engineers doing cross-reference work — if the part number doesn’t match your distributor search expectations, check whether the size is in metric vs. EIA format.

## Mid-Voltage C Series (100V to 630V)

TDK’s mid-voltage C series offers unique design capabilities for higher voltage in smaller case sizes, available in 0402 through 2220 with C0G, X6S, X7R, X7S, and X7T dielectrics, covering 100V through 630V at up to 15 µF. This range is particularly important for industrial power electronics, motor drive gate drive supplies, and 48V automotive architectures where bus capacitors need to handle both the nominal voltage and transient spikes with proper derating.

## High-Voltage C Series (1,000V to 3,000V) — Critical for EV and SiC Applications

This is where TDK is making the most aggressive product expansion right now. TDK expanded its CGA series for automotive and C series for commercial MLCCs to 10 nF at 1,250V in 3225 size with C0G characteristics — the industry’s highest capacitance for a 1,250V product in 3225 size, with mass production beginning December 2024.

The driver is silicon carbide (SiC) MOSFETs. SiC power stages in EV chargers and traction inverters operate at higher voltages and switching frequencies than silicon-based designs, which creates demand for resonant and snubber capacitors that can handle these conditions with minimal loss. C0G MLCCs change their capacitance only slightly over temperature and voltage, making them ideal for resonant and snubber applications in high-voltage circuits.

For EV DC fast charging stations, being able to specify a single 3225 C0G part at 1,250V instead of a series stack of lower-voltage MLCCs is a real BOM and assembly cost saving.

## High-Temperature C Series (X8R, to +150°C)

The high-temperature C series offers stable characteristics up to 150°C with highly precise temperature performance to 125°C, available in 0402 through 1210 with X8R dielectric, in voltage ratings of 16V to 100V at up to 10 µF.

Standard X7R tops out at +125°C. In under-hood automotive electronics, particularly near engine control units, transmission controllers, and powertrain components in EVs, ambient temperatures can routinely exceed this. X8R extends the operating window to +150°C while maintaining capacitance within ±15% — a critical specification for designs that can’t be thermally isolated from hot zones.

TDK CGA Series: Automotive-Grade MLCCs

The CGA series is TDK’s primary automotive MLCC family and has been in production supporting automotive customers for more than 30 years. TDK’s CGA series MLCCs are AEC-Q200 qualified and manufactured using a tested and stable manufacturing process, with parts subjected to increased inspections to offer a higher level of reliability guarantee.

## CGA Series Voltage Tiers and Recent Expansions

CGA Sub-Family	Voltage Range	Key Dielectrics	Notable Expansion
CGA General	4V – 50V	C0G, X5R, X6S, X7R, X7S	Capacitance up to 100 µF
CGA Mid-Voltage	100V – 630V	C0G, X6S, X7R, X7T	2.2 µF at 2012, 4.7 µF at 3216 in 100V (March 2024)
CGA High-Voltage	1,000V – 1,250V	C0G	10 nF at 1,250V in 3225 (December 2024)
CGA High-Temperature	16V – 100V	X8R	Up to 150°C operating temperature

TDK expanded the CGA series to 2.2 µF in 2012 size and 4.7 µF in 3216 size at 100V in March 2024 — the industry’s highest capacitance at these ratings — driven by 48V automotive architectures requiring miniaturized high-capacitance parts for power line smoothing and decoupling.

## CGA Soft Termination Series: Solving Flex Cracking

TDK’s automotive-grade soft termination CGA series incorporates a conductive resin layer into the terminal electrodes. This resin layer protects the ceramic body from cracks by relieving stress caused by thermal shock and board flexure.

Flex cracking is one of the most common MLCC failure modes in assembled PCBs — particularly in designs where large MLCCs (1206, 1210, and above) are placed near board breakout lines, test probe contact points, or areas subject to significant mechanical bending during assembly or use. Standard Ni/Sn terminations transfer board stress directly into the ceramic body. The conductive resin layer in soft termination parts absorbs that mechanical energy before it reaches the ceramic stack. If you’re placing 1206 or larger X7R parts on flex PCBs or near board edges, the soft termination CGA series should be your default automotive choice.

CGJ Series: High-Reliability MLCCs for Mission-Critical Designs

The CGJ series is TDK’s highest-reliability MLCC offering, positioned above both C and CGA series for applications where extended service life and traceability are paramount.

TDK’s CGJ series provides an extended-life MLCC that meets electrical, mechanical, and environmental performance standards from AEC-Q200 Rev.D. Each lot comes with access to an online Sigma Report and internet-based product authentication, including electrical characterization data and estimated product life, as well as anti-counterfeit packaging. RFID tags are also available as an option.

This kind of lot-level traceability and online quality documentation is exactly what smart meters, industrial infrastructure with multi-decade service life requirements, medical equipment, and military communication systems need. Typical applications for CGJ MLCCs include smart meters, smart grids, LED lighting, industrial equipment, telecom base stations, solar micro-inverters, EV charging stations, military communication equipment, and Class I and II medical equipment.

The anti-counterfeit packaging with product authentication is also genuinely useful. Counterfeit MLCCs are a real supply chain problem for high-volume designs. The CGJ authentication system gives procurement and incoming quality teams a direct way to verify authenticity at the lot level before parts hit the assembly line.

TDK MLCC Part Number Structure: Decoding CGA and C Series

Understanding TDK’s part numbering is essential because unlike most MLCC suppliers, TDK uses their own size code system rather than standard EIA codes. Here’s an example decode for CGA5L1X7R1H106K160AC:

Position	Code	Meaning
CGA	Series prefix	Automotive grade
5	Size code	1206 (3216 metric)
L	Thickness code	1.60 mm
1	Inner electrode material	Base metal (Ni)
X7R	Dielectric	±15% from −55°C to +125°C
1H	Rated voltage code	50V DC
106	Capacitance	10 µF (10 × 10⁶ pF)
K	Tolerance	±10%
160	Rated voltage (numeric)	Confirmation field
AC	Packaging	Tape/reel specification

The voltage code system uses letters: common codes include E (25V), F (35V/32V), G (40V), H (50V), J (63V), K (100V), L (160V), and so on. TDK publishes a complete rated voltage code table in their part number description document — bookmark it, because it’s not intuitive until you’ve used it a few dozen times.

DC Bias, Dielectric Aging, and the Traps That Catch Engineers

TDK produces some of the best application notes in the industry explaining the non-obvious behavior of Class 2 MLCCs. Two issues catch engineers who are new to high-density MLCC designs.

## DC Bias Derating in Class 2 MLCCs

Class 2 MLCCs (high dielectric constant, including X7R, X5R, X6S) exhibit a characteristic capacitance change when DC voltage is applied — this is called DC bias characteristic. DC bias characteristics must be considered whenever MLCCs are used with DC voltage applied.

The practical impact is significant. A 10 µF X7R 1206 at 50V rated might measure 10 µF at 0V bias on a bench LCR meter, but at 25V operating voltage (50% derating point) the actual capacitance may be 4–6 µF depending on the specific series. This is not a defect — it’s a fundamental property of ferroelectric ceramic dielectrics. The design implication is that you must always check the DC bias curves in the TDK product page or simulation tool, not just spec the nominal capacitance.

C0G (Class 1) is immune to DC bias effects. For timing circuits, precision filters, oscillators, and any circuit where capacitance stability under applied voltage is critical, C0G is the correct dielectric regardless of the capacitance penalty.

## Dielectric Aging in Class 2 MLCCs

Class 2 (X7R, X5R, etc.) ceramic dielectrics age over time — capacitance decreases logarithmically from the point of the last thermal reset (typically the solder reflow process). This aging rate is typically 1–5% per decade-hour depending on dielectric formulation. TDK explains how they compensate for this in their documentation, but the key point for engineers is that production test measurements and field capacitance measurements can differ by several percent, and this must be budgeted in your worst-case circuit analysis — particularly for timing, filtering, and resonant circuit applications.

TDK’s Design Tools for MLCC Selection and Simulation

TDK provides a genuinely strong set of free design tools. Using them saves real time and catches problems before prototyping.

TDK Characteristic Search Tool at product.tdk.com/en/search/capacitor/ceramic/mlcc/characteristic — parametric search by capacitance, voltage, case size, dielectric, and temperature range. Much more efficient than distributor catalog searches for identifying the correct TDK part number.

TVCL (TDK Virtual Component Library) — SPICE simulation models for TDK MLCCs compatible with HSPICE, LTspice, and PSpice. TDK’s dynamic DC Bias Model enables designers to simulate DC bias characteristics of MLCCs even when the DC bias voltage changes dynamically — an industry first at its launch. The model is available in HSPICE, LTspice, and PSpice formats and can be downloaded free of charge. If you’re simulating a DC/DC converter output stage with TDK MLCCs, this dynamic model gives you far more accurate transient behavior than static single-bias-point models.

SIM-CAL STUDIO — TDK’s power supply design tool that proposes appropriate MLCCs and inductors based on converter operating conditions, including series/parallel MLCC configuration proposals for LLC resonant circuits with high-voltage Class 1 parts.

CLARA (Capacitor Life And Rating Application) — primarily for EPCOS/TDK film capacitors, this tool provides application-condition simulation including thermal derating, lifetime estimation, and comparative analysis of up to four part numbers simultaneously.

TDK MLCC Applications by Market and Use Case

Application	Recommended TDK Series	Key Requirement Driving Selection
General commercial decoupling	C series X7R, 4V–50V	Widest availability, lowest cost
Automotive ECU power rails	CGA general X7R	AEC-Q200, PPAP documentation
Under-hood ECU, 150°C	CGA high-temp X8R	Extended temperature to +150°C
Flex circuit / board-edge placement	CGA soft termination	Conductive resin termination for flex crack
Smart meter / industrial long-life	CGJ series	Extended life, Sigma Report, authentication
SiC inverter snubber / resonant	CGA/C high-voltage C0G	Stable under voltage, low loss, 1,250V rated
AI server PSU / IBC 48V bus	C series 100V large cap	High cap density at 100V for 48V bus decoupling
RF / precision timing	C series C0G	Zero DC bias effect, zero aging
EV 48V architecture power filtering	CGA mid-voltage X7T	100V rated, miniaturized high cap

Useful Resources for TDK Capacitors

Official TDK Product and Catalog Links

• TDK MLCC Parametric Search — Find MLCC by capacitance, voltage, case, dielectric, temperature
• TDK C Series Commercial MLCC Catalog (May 2025) — Complete commercial general-voltage lineup
• TDK CGA Series Automotive MLCC Catalog (March 2025) — Automotive general-voltage lineup with AEC-Q200 data
• TDK Automotive High-Voltage MLCC Catalog — High-voltage CGA including 1,250V C0G additions (Dec 2024)
• TDK CGA Soft Termination Catalog (Dec 2024) — Automotive soft termination series with flex crack resistance
• TDK MLCC Part Number Description — Rated voltage codes, size codes, packaging codes

Design Tools and Simulation Resources

• TDK TVCL SPICE Models for MLCC — Free LTspice / HSPICE / PSpice models including dynamic DC Bias Model
• TDK SIM-CAL STUDIO — Power supply circuit MLCC and inductor selection tool
• TDK MLCC Design Tools Overview — Mid/high voltage MLCC configuration proposal tools
• TDK Electrolytic-to-MLCC Replacement Guide — DC bias, anti-resonance, and oscillation guidance for converter output stage designs
• TDK MLCC for Data Center PSU Application Note — AI server power chain MLCC recommendations by stage

Distributor Technical Resources

• DigiKey TDK CGA Series Guide — Series overview with MLCC aging explanation and electrolytic replacement guide
• Mouser TDK CGJ High Reliability Overview — CGJ series application context with Sigma Report explanation

5 Frequently Asked Questions About TDK Capacitors

Q1: What is the difference between the TDK C series and CGA series — can I use C series in automotive designs?

The short answer is: C series is commercial-grade, CGA is automotive-grade, and you generally cannot substitute C series into automotive designs without your Tier 1 customer pushing back. The functional difference is AEC-Q200 qualification and PPAP documentation availability. CGA parts go through additional inspection and reliability testing to meet automotive standards. If you’re designing a consumer product or an industrial device without an automotive customer requirement, C series is appropriate. For anything that goes into a vehicle — even a cabin accessory — start from CGA and document why in your design rationale. Using commercial grade to save a few cents per part is rarely worth the qualification debate later.

Q2: How do I account for DC bias derating when designing with TDK X7R MLCCs?

Always use TDK’s parametric search or TVCL models to check the DC bias curve for the specific part you’ve chosen, not just the nominal capacitance spec. A practical rule: for X7R parts at a rail where DC voltage is more than 30–40% of the rated voltage, expect actual capacitance to be substantially lower than the nominal value — potentially 50% or less in extreme cases. For bulk decoupling on a 3.3V rail using a 10V rated X7R, the derating is modest. For a 47 µF X7R on a 12V rail using a 16V rated part, the real capacitance at operating conditions might be well under 20 µF. TDK’s dynamic DC Bias SPICE model lets you simulate this accurately in LTspice before committing to a BOM. C0G parts have zero DC bias effect and are the correct choice where actual capacitance under bias must match nominal.

Q3: When should I specify TDK CGJ instead of CGA for an industrial design?

CGJ is appropriate when the application demands extended service life documentation, traceability beyond standard AEC-Q200, or when counterfeit mitigation is an explicit procurement requirement. The CGJ’s Sigma Report and online product authentication give each production lot documented electrical characterization data and estimated product life — this is not available for standard CGA parts. If you’re designing smart meters with 20-year field life requirements, industrial infrastructure in unmaintained installations, or equipment where capacitor field failure is a safety-critical event, CGJ’s additional documentation is worth the cost premium. For standard automotive ECU or ADAS applications, CGA is sufficient. Use CGJ where the supply chain risk profile or service life documentation requirement explicitly calls for it.

Q4: What is the TDK soft termination CGA series and when should I use it?

The soft termination CGA series incorporates a conductive resin layer between the ceramic body’s inner terminations and the standard Ni/Sn outer terminations. This resin layer acts as a mechanical buffer — when the PCB flexes (during depaneling, in-circuit testing, handling, or thermal cycling in the field), the resin absorbs the mechanical stress instead of transmitting it to the ceramic. Without soft termination, that stress can propagate a crack through the ceramic body, which manifests as a capacitance drift at best or a dead short at worst. Use soft termination for any MLCC in a 0805 or larger case size that is placed within 5mm of a PCB breakout line, near test fixture contact points, or in any design where the PCB experiences significant flexure during its service life. The cost premium is modest and the reliability improvement in flex-prone assemblies is meaningful.

Q5: Can TDK high-voltage C0G MLCCs replace film capacitors in resonant circuits?

Increasingly, yes — and TDK has published detailed application guidance on exactly this topic. Film capacitors have traditionally been the default for resonant circuits in wireless chargers, LLC converters, and power factor correction stages because of their low ESR, stable temperature coefficient, and high voltage ratings. Advances in high-voltage MLCC capacitance expansion have made it possible to replace film capacitors with C0G MLCCs in resonant applications, offering benefits including miniaturization and reduced losses. The key requirements for resonant capacitors — stable capacitance vs. temperature and voltage, low ESR, and high voltage rating — are precisely the strengths of C0G Class 1 MLCCs. TDK’s recent 10 nF / 1,250V in 3225 size for SiC resonant stages is a direct product response to this trend. Before assuming a film capacitor is necessary, check whether a TDK high-voltage C0G MLCC meets the required capacitance, voltage, and loss specifications — you may be able to reduce board area and improve temperature stability simultaneously.

Putting TDK’s Ceramic Portfolio to Work

The key mental model for TDK capacitors is a matrix of two axes: qualification tier (C → CGA → CGJ) and voltage/temperature class (general → mid-voltage → high-voltage → high-temperature). Every TDK MLCC has a clear position in this matrix, and the selection process is about identifying where your application sits on both axes before opening the parametric search tool.

Download the TVCL dynamic DC bias models for any X7R or X5R part you’re using in a power supply or decoupling application. The simulation accuracy improvement over datasheet nominal values is significant enough to change BOM decisions — and finding out you need 20% more capacitance in simulation is far cheaper than finding out in validation testing.

TDK’s application notes on electrolytic capacitor replacement with MLCCs, resonant circuit design, and data center power systems are among the best publicly available MLCC application references in the industry. They’re worth reading even if you’re not currently using TDK parts, because the underlying physics applies across manufacturers.