IConnect Short Interconnect Modeling Single-Ended TDR: Package Lead Inductance L Measurements
{"Image DocumentName": "IConnect Short Interconnect Modeling Single-Ended TDR: Package Lead Inductance L Measurements", "Image ImageDescription": "TDR waveform: TDR into package lead. Short all the leads to ground on the inside of the package. Short the leads that are not being measured to ground on the outside of the package. Short waveform: TDR into the short ; connect the probe signal contact to ground on a conductive (metal) pad. For self inductance Lself, a reference short waveform is now required, which is obtained by shorting the measurement probe signal lead to ground on a piece of conductive material, such as copper. The difference between the TDR waveform of the package trace and the reference open TDR waveform will now give us the lead inductance. Fixturing requirements limit the usability of this method of inductance measurements to packages that are easily accessible on the inside. This may be a preferred method for small packages such as TSSOP, SOIC, CSP; however, if the number of leads used for a current return path to ground is small, the inductance of the return path is extracted in addition to the lead inductance. This method can also be used for larger packages, such PGA and QFP, as long as the lumped model approximation for the package lead holds. The advantage of this method is that the technique is simple, well understood and standardized. The disadvantages for package inductance measurement are obvious. There is also great possibility of not taking into account coupling of energy into leads adjacent to the lead under test. We found it to be pretty good for large packages (PGA, QFP) which had fairly high inductances and lots of faraway leads to use for a return path. However, for small packages with few extra leads, the inductance of the return path can hide that of the lead. For all types of packages, we considered the differential method to be more accurate. Induced waveform: Measure near end crosstalk with far end of the victim shorted. Background waveform: Corrects for the noise and scope DC offset. Tektronix Confidential.", "Image XResolution": "37", "Image YResolution": "37", "Image ResolutionUnit": "Pixels/Centimeter", "Image Software": "SlidePlayer", "Image YCbCrPositioning": "Centered"}