Howtosignalprocessing
What is the recommended AC coupling capacitor value in PCIe? The transceiver user guides for GTX/GTH/GTY specify 100 nF as the recommended value for the AC coupling capacitor on the transceiver TX/RX pins. However, the PCI Express Base Specification calls for 176 to 265 nF capacitor value.
- How do I choose an AC coupling capacitor value?
- Why AC coupling capacitor is used in PCIe?
- Which capacitor is used for coupling capacitor?
- How do you calculate a coupling capacitor?
How do I choose an AC coupling capacitor value?
A coupling capacitor is best selected so that its impedance is as low as possible at the frequency of interest. The impedance magnitude at any frequency is easily calcu- lated as: Since the net reactance is zero at the capaci- tor's FSR, the total impedance will be equal to the ESR at this frequency.
Why AC coupling capacitor is used in PCIe?
Coupling capacitors find plenty of uses in analog applications and on differential protocols, acting essentially as high pass filters that remove DC bias carried seen on a signal. In PCIe routing, coupling capacitors are used for the same function (removing DC offset), but for different purposes.
Which capacitor is used for coupling capacitor?
Polyester film capacitors, commonly used for coupling between two circuits.
How do you calculate a coupling capacitor?
An input coupling capacitor acts as a high pass filter together with the input impedance. The formula for the calculation is C = 1/(2pi*f*Zin) where C is the capacitance, f is the corner frequency and Zin is the input impedance.
