Hi Shravani, The coplanar waveguide (CPW) is a planar transmission line used majorly in microwave and millimeter-wave applications. It consists of a signal trace surrounded by two ground planes on the same substrate layer. This configuration allows efficient signal propagation, reduced radiation loss, and easy integration with other circuit components.
Thank you so much for wonderful overview. What is the difference between R/C/L_pkg, R/C/L_pin? Usually a component in IBIS file has multiple pins. Each pin has its own R/L/C parasitics which are mentioned per pin using R/L/C_pin. Then what is the real significance of R/C/L_pkg parameters?
Hi Mahesh, C_comp represents the Capacitance value in the buffer and is measured with min, max and Typical value. This value is usually the capacitance of the transistor and die. Please don’t confuse this capacitance value with package capacitance.
If you don’t want to use the termination, the stack up analysis need to be performed properly, it also depends on the dielectric material used and majorly on the copper thickness / dielectric Height
If you need to design a cost effective stack up without adding termination, you need to do following things 1. Select the metal and dielectric material in such a way that the Impedance across the trace remains nearly equal to driver Impedance ( tough to achieve) 2. Trace width and dielectric height need to be modelled in such a way that the impedance of trace is equal to that or tx and rx.
Hi Hemnath, Thanks for the query||| Defining Rise time: The rise time in digital systems describes how long a signal spends in the intermediate state between two valid logic levels. 1. The signal rise time determines if a line will behave as a transmission line or as a lumped circuit. 2. A line will act as a transmission line if its electrical length is greater than half the signal rise time. 3. The faster the rise time of a circuit, the wider the bandwidth and higher the frequencies that the circuit can effectively transmit around the board.
Hi Hemnath, Thanks for the query!!! Crosstalk is due to mutual capacitance and inductance, as we know the transmission line is the combination of RLGC circuit, the factor dielectric Constant (Er) is directly proportional to the capacitance value. This logic directly relates us to the capacitance created, which can be modulated by improving the Dielectric material.
There are various factors that play a vital role in behaviour of insertion and return loss. Sone of them are: 1. Reflection : this controls the magnitude of return loss, ( Using decap having resonant frequency nearest to dip frequency help resolving this issue) 2. Materialistic losses: This governs the insertion loss as it depends on the materialistic loss such as loss due to Dielectric material having different dielectric constant, thickness etc
Clearly understood resonance frequency. Thank u very much for a nice explanation. Your videos are very useful for learning signal Integrity. waiting for next video
Hi Suresh, Without IBIS models, the extraction of S-parameter( Insertion loss and Return Loss plots) can be performed , it doesn't require Models for TX and Rx. But if you require to perform the channel extraction, you will Need tx Rx models.
@@bhardwajh_2701 for AIO differential pins no IBIS model provided . How can we ensure that giga bit Ethernet differential pairs SI (eye diagram ) is proper or within limits in the board(tracks) ,from ethernet out to the Connector through a Transformer?
There is a dielectric material between two copper traces in a pcb .....there is no filed between them .. because of dielectric !!! How two llel traces forms an capacitance?
Thanks for the Query... "In the given example we tried to explain taking capacitor basics into consideration. In PCB, the stackup is created in such a way that each signal layer has the empty space which is filled with Dielectric material by default. Therefore, the two traces acts as parallel plates of a capacitor having a dielectric material between them.
@@bhardwajh_2701 what is the minimum width to be maintained to eliminate capacitance between the traces one in top and one in bottom of same core or both on the same side ? The prepeg material is dielectric means there is no flow of electrons,how capacitance effect forms ..if it formed how it will charge and discharge? Can I expect more videos on SI/PI ??
Hi Suresh, " This totally depends on the design parameters, As per industries standard, we keep 2W and 3W spacing between to traces. You can check out crosstalk video for more clarification on the same
Super explanation .... expecting more from u ...need more videos on signal integrity (s parameter and Differential signal ) simulation using hyperlynx si/pi.
Hi Mahesh, thanks for the Query. " The Ground plane acts as a return path for the current. From the basics, if we see" current always flow in a closed loop. That's the main reason we use Ground via to connect and complete the current loop for the particular signal"
