Ceramic Capacitors
1. Ceramic Capacitors Overview
Ceramic Capacitors are capacitors with ceramic materials as dielectrics. Their core structure is made of multiple layers of ceramic dielectrics and metal electrodes alternately stacked and sintered at high temperatures to form a compact structure similar to a “monolith”, so they are also called “monolith capacitors”. SMD multilayer ceramic capacitors (MLCC) are the mainstream type, with the characteristics of miniaturization and high integration.
2. What are the Types of Ceramic Capacitors?
1) By Frequency Characteristics:
Low-frequency Ceramic Capacitors: Suitable for bypass or DC isolation scenarios in low-frequency circuits.
High-frequency Ceramic Capacitors: With low loss and high stability, they are often used in high-frequency oscillation circuits.
2) By Dielectric Type:
Class 1 (C0G/NP0): Excellent temperature stability (±30ppm/℃), suitable for precision circuits.
Class 2 (X7R/X5R): Medium capacity and temperature stability, used for general circuits.
Class 3 (Y5V/Z5U): large capacity but poor temperature stability, suitable for low-cost applications.
3) By packaging form: disc, tubular, rectangular, patch (such as MLCC), etc.
3. What are the Core Characteristics of Ceramic Capacitors?
High Withstand Voltage and High Insulation: The dense structure of ceramic dielectric supports high-voltage scenarios (up to several thousand volts).
Low Equivalent Resistance (ESR): usually in the milliohm level, reducing energy loss.
Excellent High-frequency Characteristics: suitable for high-frequency circuits such as radio frequency and communication.
Miniaturization: MLCC size can be as small as 0201 (0.6mm×0.3mm) level, meeting the needs of electronic equipment for thinness and lightness.
4. Where are Ceramic Capacitors Used?
High-frequency Circuits: such as radio frequency modules, filters, and resonators.
Power Management: used for bypass, decoupling, and energy storage scenarios.
High-voltage Scenarios: such as high-voltage coupling and bypass of TV receivers and industrial equipment.
Precision Electronics: fields with high requirements for stability, such as instruments and digital-to-analog conversion circuits.
5. Parameters and Selection Points for Ceramic Capacitors
Capacity Range: MLCC has a large capacity span (1pF~100μF), and low-frequency ceramic capacitors have a small capacity (usually ≤0.01μF).
Temperature Coefficient: The matching temperature compensation type needs to be selected according to the working environment (such as C0G is suitable for wide temperature environments).
Accuracy Requirements: The general accuracy is 5%~25%, and Class 1 medium needs to be selected for high-precision scenarios.
6. Development Trend of Ceramic Capacitors
MLCC technology continues to develop towards higher capacity, smaller size (such as 01005 package), and better high-frequency/high-voltage performance while improving reliability by improving materials and processes (such as Fail-safe design).
7. Typical Brands for Ceramic Capacitors
Semtech
TDK
Vicor
YAGEO
MuRata
TAIYO YUDEN
KEMET