New Industry Products

Accurate Power Distribution Network Impedance Measurements

October 17, 2019 by Paul Shepard

Picotest has released a new interconnect cable especially designed for power distribution network (PDN) impedance testing. According to the company, these cables offer an unmatched combination of low loss, flexibility, and low shield resistance.

The Picotest PDN Cables and the J2102B Common Mode Transformer pictured above combine to enable the 2-port shunt-through measurement using the OMICRON Lab Bode 100 and other manufacturers‘ VNAs and FRAs.

Picotest observed: As bus voltages have fallen and dynamic current demands have grown, the impedance levels of power distribution systems have fallen. Today's electronics have significantly more power rails than ever before. And in most cases, the only practical method of assessing and optimizing their performance is through their PDN impedance profile. The 2-port shunt through method is the gold standard in the industry for testing impedance. But there are many sources of error given bus impedances are in the milliOhm and even microohm region.

"The cables target ultra-low impedance measurement and maintain flexibility while providing outstanding shielding, low shield resistance and 18GHz performance," stated Steve Sandler, CEO of Picotest.

The Picotest PDN Cable is designed to support the 2-port shunt-through impedance measurement. The cables target PDN applications where impedance and stability measurement is critical to system performance. The largest source of error in impedance measurement is the cable shield resistance, followed by the ground isolator (J2102B), required to remove the inherent ground-loop in the 2-port shunt through test setup.

Picotest has now optimized both sources of error, allowing more accurate measurements well below 100uOhms. The PDN Cable is optimized for PDN measurements but is highly suited for SI measurements as well.

Features include:

  • Reduced shield resistance for more accurate PDN impedance measurements
  • Brass soldered connectors for reduced shield resistance
  • Very thin -- Ultra-flexible 18GHz cable optimized for PDN and SI testing
  • Santoprene jacket good to +125C for temperature chamber measurements
  • Triple shielded for added noise suppression
  • Custom made assemblies are 100% TDR tested for discontinuities and defects

The PDN Cables, available immediately, come in pairs (2 cables) with 0.5M and 1M lengths. It is also available in bulk form. PDNCBL1M is available for $495 (1M length) while PDNCBL0P5M is $395 (0.5M length).

The J2102B common mode transformer/ground loop breaker is available in two configurations; one with BNC connectors and one with N connectors. The price of both the J2102B-BNC and the J2102B-N is $799. The J2102B is CE certified.