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In-Circuit Design Pty Ltd (ICD), Australia, developer of the iCD Stackup and PDN Planner software, has released a new Termination Planner feature for its Stackup software.
The key pillars of high-speed design stability are stackup impedance, PDN impedance, and matched impedance. ICD currently has the first two issues covered with the Stackup and PDN Planner software. And now, the Termination Planner feature has also been introduced to complement the existing software.
“For perfect transfer of energy and to benefit from the highest possible bandwidth, the impedance of the driver must match the impedance of the transmission line and be constant along its entire length,” said CEO Barry Olney. “Unfortunately, using mainstream PCB layout software, one really has no idea what the driver impedance is, let alone the capability to match the driver to the unknown impedance of the transmission line.”
The ICD Termination Planner addresses this issue. Firstly, the attributes required to determine the source impedance of the driver, are extracted from an IBIS model IV curves. Then the required series termination resistance is calculated, based on a distributed system, to match the transmission line for the selected layer in the iCD Stackup Planner. If the IBIS model is not available (or produces an error) the user may use Generic models to calculate an approximate series termination. Generic models include: typical DDRx, Display Port, ECL, HDMI, LVCMOS and LVTTL gates, Mini-LVDS, NAND Flash, PCI, SDRAM, HSTL and SSTL models.
The number of loads on the transmission line also has an affect on the required value of series termination; as the IC input inductance and capacitance tend to roll-off the signal rise time. This can be adjusted from 1 – 6 loads and automatically compensated for in the calculation.
This new feature will be delivered to current ICD support customers as part of an interim upgrade and will be also made available as part of a new Stackup Planner acquisition.
A quick demonstration of the new ICD Termination Planner can be viewed here.
About In-Circuit Design Pty Ltd
In-Circuit Design Pty Ltd, based in Australia, developer of the ICD Stackup and PDN Planner software, is a PCB design service bureau and specialist in board level simulation. For further information or to download a free evaluation of the software, please visit www.icd.com.au