PI3EQX16904GL is a four-differential channel linear ReDriver. It is also PCIe-compliant. PCIe stands for peripheral component interconnect express and PCIe 4.0 is the standard’s latest version.
According to the company's announcement of the ReDriver, "The device provides programmable linear equalization, output swing, and flat gain to optimize performance over a variety of physical media by reducing inter-symbol interference."
Block diagram for the PI3EQX16904GL. Image from Diodes Incorporated
Diodes Inc. claims that the PI3EQX16904G is the first ReDriver compliant with PCI-SIG’s PCIe 4.0 specification while also being backward compliant with PCIe’s older 3.0/2.0/1.0 standards. It also supports the SAS3/ IB FDR/ PCIe4/ FC16, and XAUI protocols.
Target applications for the devices include:
- Storage and AI servers
- 5G networking
- CPU-to-network (PCIe NIC card)
- CPU-to-storage non-volitile memory express (NVME) interconnects
- CPU-to-CPU interconnects within high-performance compute clusters
A listing and descriptions of Diodes Incorporated’s ReDrivers and related devices can be found here.
What Is a ReDriver?
Data rates are rising in electronic devices of all sorts. In some cases, that data must travel longer physical distances, often through a sea of EMI/RFI, from source to destination. This can cause the degradation of signal integrity.
ReDrivers (or re-drivers) are another term for repeater ICs. They serve to “re-drive” the signal, to amplify it and to remove distortion, so a clean, workable data-stream emerges.
The PI3EQX16904GL employs techniques such as equalization and pre-emphasis to adjust and correct for factors on both the transmitter end (known channel losses) and also to restore signal integrity on the receiver end. This improves the reliability of communications and enables low bit error rates (BER).
Four Lane Data Traffic
A “lane” in this context is composed of four wires forming a differential channel. One pair of wires (or PCB signal traces) carries data in one direction and a second pair of wires carries data in the reverse direction, creating a differential channel.
Each of the eight separate, 100-Ohm pathways supported and augmented by the PI3EQX16904GL supports data rates ranging from 2.5Gbps to 16Gbps.
The device requires a supply voltage of 3.3V ±0.3V, and it operates over a temperature range of -40˚C to +85˚C temperature range.
The unit is lead-free, halogen-free, and antimony-free. It is also RoHS compliant.
The PI3EQX16904GL ReDriver is available in a 9mm x 3.5mm, 42-contact TQFN package.
The PI3EQX16904GL. Image from Diodes Incorporated
Diodes Inc. seems the be the first company to offer a device such as the PI3EQX16904GL. But, given, the widespread adaptation of the PCIe standard, it’s doubtful that the distinction will last for long. However, here are a couple of notable related devices:
- Asmedia Technology offers the ASM1464 … ASM1467 series of one-lane, 100-ohm 5Gbps ReDrivers. They serve in USB- and-SATA based applications in addition to PCIe.
- Texas Instruments offers the S125BR820, a low-power repeater/ReDriver designed to support eight channels. These channels carry high speed interface up to 12.5 Gbps, such as 40G-CR4, 40G-KR4, SAS/SATA, as well as PCIe.
Have you worked with PCIe before? What's your familiarity with repeater ICs and their applications? Share your thoughts in the comments below.