Introduction to 3 terminal capacitor

1

Reference : [11] 2

With decoupling capacitors, the voltage ripple and noise emission can

be reduced [10].3

The lower ESL is, the wider capacitive range will be.

The lower ESR is, the better noise suppression will be [12].

4

The path the noise flows inside 3-terminal capacitor is shorter than

which inside 2-terminal capacitor. That’s to say, the 3-terminal

capacitor has lower ESL and ESR [12,13].

C = 10 uF 5

With lower ESL and ESR, the 3-

terminal capacitor has wider

capacitive range and better noise

suppression than 2-terminal one [7,9]

6

Although signal must pass through the whole 3-terminal capacitor.

Nevertheless, as mentioned above, the ESR of 3-terminal capacitor

is extremely small. Thus, the loss is negligible.

Feed ThroughElectrode

GND Electrode

Signal Flow

7

Lower ESR => Lower Voltage Ripple.

Lower ESL => Smaller loop area =>

lower Noise Emission [10].

8

For noise reduction,

one 3-terminal capacitor is even better than

(1 bead + 2 * 2-terminal capacitor )[1].

9

For noise reduction,

one 1uF 3-terminal capacitor is even better than

(4 * 0.22 uF 2-terminal capacitor )[6].

10

For noise reduction,

one 10uF 3-terminal capacitor is even better than

(22uF + 10 nF x 5pcs + 100 pF x 5pcs)[4].11

Compared to multiple capacitors, the 3-terminal capacitor

doesn’t have anti-resonance issue. Besides, the 3-terminal

capacitor can save PCB area due to less components[5,12].

12

In addition, the number of GND via is the more the better. By

doing this, the impedance of noise path can be reduced further,

which can lead to better noise suppression[7,8].

13

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