Allion Labs / Casper Lee

Continuing from the last article, we will introduce the related functions of the Allion U.2/U.3 (APT21071) Test Fixture. As mentioned before, this test fixture can be used to measure SAS and PCIe signals simultaneously.

A. U2/U.3 connector

Using the newest SAS connector, it can meet the specifications of SAS4 and PCIe Gen5.

B. Front side

There are PCIe1/PCIe2 and SAS0 SMPM connectors on the front side.

  1. The PCIe1 & PCIe2 connectors can be used to measure U.2/U.3 PCIe Lane1 & Lane2 signals.
  2. The SAS0 connector is used to measure the SAS Port0 signal. Meanwhile, the PCIe1 connector can also be used to measure the SAS Port2, and the PCIe2 connector is used to measure the SAS Port3 signals.

C. Back side

There are PCIe0/PCIe3, SAS1 SMPM, and Clock Reference SMA connectors on the back side.

  1. PCIe0 & PCIe3 connectors can be used to measure U.2/U.3 PCIe Lane0 & Lane3 signals.
  2. The SAS1 connector is used to measure the SAS Port1 signal.
  3. The clock reference connector is used to connect clock signals to the scope.

Based on Allion’s domain knowledge for validation testing throughout the decades, we recognize how complex it is coordinating fixtures, instruments, equipment, and operations during testing. Sometimes, the original fixture design does not take into consideration the test operations and procedures, creating a test fixture which does not necessarily make the job easier for the test engineer. To correct this problem, we advanced and improved the deficiencies of the original test fixture, creating a fixture that allows for smoother, simpler testing.

1. Strengthening of the Connector Structure

To improve the connector’s poor tolerance and decrease the probability of damage during use, Allion uses high-frequency connectors with bandwidth exceeding 40 GHz.

2. Modular Connector and Cables

Allion’s set of modular integrated connection cables can be directly connected to related test equipment without additional cables, which greatly reduces the number of cables used during testing, as well as the frequency of plugging and unplugging. This means there is no need to purchase extra cables. Allion also prepares different lengths and connector types to meet usage demands.

Using fixtures developed by Allion gives you more flexibility and convenience. If you have any questions regarding PCIe test fixtures, please feel free to contact us at: