Chapter III: Electro-Magnetic Compatibility (EMC) TAIYO YUDEN CO., LTD. http://www.ty-top.com

Impedance Characteristics of Capacitor Impedance equivalent circuit with capacitor is the same as the RLC series model. Changes in Frequency Changes in Element Impedance Capacitance decreases What happens to the impedance level when connected in series?

Impedance Characteristics of Capacitor Impedance for series connection Impedance with different elements 100 インピーダンス　[Ω] Impedance Impedance depends on capacitance Resonance Point 周波数　[MHz] Frequency • At resonance point, no impedance for Capacitor & ESL (Impedance for ESR only) • The frequency at resonance point depends on Capacitor & ESL Resonance Point →Cap. : Increase, ESL: Increase 0.01

Impedance Characteristics of Capacitor ESR varies depended on frequency Frequency characteristics for different type of capacitors Impedance,ESR Freq.-Temperature Characteristic 周波数　[kHz] Frequency RLC Series Model→ ESR independent from frequency RLC varies depended on capacitor’s material, structure and case size Frequency characteris

1. Operational condition comparison chart for Circuit u Vertical style © Horizontal style Electrolytic paper Electrolysis solution Ca, Ck: positive/negative pole cap. Da,Dk: rectification from negative pole’s oxidization coating La,Lk: Inductance for +,- leads R: resistance of electrolsis solution and paper Ra,Rk: Inside resistance of forward direction from +,-poles’ oxidization coating <Surface mounted> Ceramic Capacitor Breakdown Voltage (V) Breakdown voltage level comparison: rated voltage 10V 500 Forward direction

Characteristics Comparison for the Different Type of Capacitors Frequency Characteristics 100 インピーダンス・ESR　[Ω] Impedance ESR varies greatly depended on each type of capacitors. Al>Ta>Functional Ta>Functional Al>ML The lower ESR becomes, the lower the impedance for high frequency gets. Al>Ta>Functional Ta>Functional Al>ML

Characteristics Comparison for the Different Type of Capacitors Ripple Current Characteristics Ripple current characteristics for the different type of capacitors リップル電流対部品温度上昇の比較 Temperature rise characteristic due to ripple current Capacitor Ripple current Temperature rise (degree) Electrical energy is converted to heat when current goes through resistance. M LCC47uF 積層コン４７μF Tant.Cap47uF タンタル４７μF POSCAP１００μF POSCAP100uF リップル電流（Aｒｍｓ） Ripple current(Arms) Given the same amount of calorific power, ripple current goes through MLCC the most because of its low ESR. Electrical energy is converted...

The Basic Knowledge of Circuits TAIYD YUDEN

The Functions of Bypass (decoupling) Capacitor The Role of Bypass Capacitor Noise + Load current Load Current Power supply line |=!>——sr<=>-Noise Current To connect the noise current to the earth (grounding) Necessary Characteristics for Bypass Capacitor It has low impedance. (low prevention of an electric current) d It electrifies an electric current well. d It efficiently grounds the noise current. d It effectively decreases the noise current. The principle of operation for Bypass Capacitor f DC does not go through the capacitor " (Impedance:^) DC is supplied directly to IC AC (noise) does...

The Functions of Bypass (decoupling) Capacitor Replacement of Ta capacitor by Bypass Capacitor Selection Criteria for Capacitor 1000 Increasing in noise suppression effectiveness Decreasing in noise suppression effectiveness Change product name 100 to MLCC + capacitance 10 Impedance,ESR Freq.-Temperature Characteristic Maximum level for noise suppression effectiveness When the frequency is over 10kHz, the impedance of MLCC is lower than that of Ta capacitor. Several kinds of Noise Frequencies Effectiveness of reduction in high frequency noise for MLCC is more superior than that of Ta capacitor....

The Functions of Backup Capacitor Load current doesn’t stay constant. Load current: small Load current: large High-speed load change Load current When IC’s operational speed changes rapidly, large load current is quickly needed. Low-speed operation High-speed operation Power line for high-speed load changing The current can’t flow Large load current is to IC quickly enough. quickly needed. Line voltage Line voltage Line voltage can’t be maintained, therefore voltage is dropped. Voltage dropped Line voltage Low-speed operation High-speed operation Circuit voltage, Load current Minimum required...

The Functions of Backup Capacitor Capacitor’s actual (considering equivalent circuit) The Role of Backup Capacitor Electric current delays Line voltage Line voltage, needed load current, Discharge current from Capacitor Voltage dropped by electric current Low-speed operation Maintaining Line voltage Minimum required operational voltage for IC Voltage dropped by discharge current Line voltage dropped Voltage fluctuation occurs when capacitor charging High-speed operation Line voltage Voltage dropped ∗This is a simplified version, so disregard ESL Making up for electric current shortage Voltage...

The Functions of Backup Capacitor Experimental circuit R = 1Ω Power Supply Voltage= 5V Experimental result for Capacitance and ESR タンタル１００μFのリップル電圧 Ripple Voltage of 100uF Ta Cap ESR による電圧変動 Voltage fluctuation by ESR Pulse generator 1945 (NF) MLCC 47µF∗7 Rating Capacitor Current probe Voltage fluctuation 容量による電圧変動 by capacitance Switching frequency = 1000KHz １μS／Div MLCC 22uF 積層コン２２μＦ Ta Cap 100uF タンタル１００μＦ The fluctuation band of line becomes narrower. It enables to replace Ta capacitor with a smaller value of MLCC.

Application Examples for Backup Capacitor OSコン １０μF ５０ｍV／Div ５０ｍV／Div OSコン ４７μF OSコン １００μF ５０ｍV／Div ２．５μS／Div

The Basic Knowledge of Power Supply Circuit TAIYD YUDEN

Series Regulator (3 Terminal Regulator) Circuit operation (water gate model) Load current fluctuation Controlling element (transistor) Controlling element (transistor) Load current Load current Producing output voltage by lowering certain amount of input voltage 4a Step-down power supply Controlling water gate to keep the water level constant Controlling load current with transistor Output voltage stays constant.