NXP Semiconductors PX1011B-EL1/G,551

Overview

PX1011B-EL1/G,551 from NXP Semiconductors is a single-lane, 2.5 Gbit/s PCI Express stand-alone PHY IC compliant with PCIe Base Specification Rev. 1.1. It implements full SerDes, 8b/10b encoding/decoding, CDR, elastic buffer, and receiver detection, interfacing via an 8-bit SSTL_2 PXPIPE at 250 MHz to FPGA-based MAC layers in embedded computing and industrial control systems.

For engineers reviewing the PX1011B-EL1/G,551 datasheet, PX1011B-EL1/G,551 pinout, PX1011B-EL1/G,551 application, or PX1011B-EL1/G,551 equivalent, this page delivers verified electrical parameters, LFBGA81 package mapping, power management state behavior (P0/P0s/P1), JTAG BIST capability, and precise RX/TX differential signaling details required for PCIe link design validation and FPGA integration.

Technical Context

The PX1011B-EL1/G,551 implements a full physical layer stack: a PLL-based clock generator synchronized to a 100 MHz ±300 ppm reference clock drives both 250 MHz source-synchronous TXCLK/RXCLK and internal 2.5 Gbit/s serial bit rate. Its SerDes includes on-chip 50 Ω termination for PCIe differential I/O (RX_P/RX_N, TX_P/TX_N) and supports spread-spectrum clocking to reduce EMI.

Functional blocks include a Clock and Data Recovery (CDR) circuit for jitter-tolerant lock acquisition, an elastic buffer managing ±600 ppm frequency skew via SKP symbol insertion/removal, and a PCS layer performing 8b/10b encode/decode with word alignment via K28.5 comma detection - all operating under strict PCIe timing constraints for LTSSM state transitions and electrical idle compliance.

Key Specifications

Pinout & Package

LFBGA81 package (9 × 9 × 1.05 mm, SOT643-1), Pb-free (SnAgCu solder balls), 81-ball fine-pitch array with standard ball pitch and thermal pad-compatible layout.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCIe Gen 1 PHY applications.

Compared with IDT8N34S201BGI and TSB51101RGZR, the PX1011B-EL1/G,551 offers superior integration for single-lane endpoints through its hardware-managed elastic buffer, native spread-spectrum support, and direct SSTL_2 FPGA interface - reducing BOM count and PCB area while maintaining full PCIe 1.1 conformance.

Availability

PX1011B-EL1/G,551 is available at Aetrix Electronics and suitable for industrial control systems, FPGA-based embedded controllers, medical imaging subsystems, and test equipment requiring stable component supply with guaranteed long-term availability.

Supply support for PX1011B-EL1/G,551 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The PX1011B-EL1/G,551 belongs to NXP's PCI Express PHY product line, designed specifically to offload physical layer complexity from FPGAs and ASICs in cost-sensitive, high-reliability embedded systems requiring Gen 1 PCIe interoperability.

FAQ

What PCIe specification versions does the PX1011B-EL1/G,551 support?

The PX1011B-EL1/G,551 is compliant with PCI Express Base Specification Revision 1.0a and Revision 1.1. It fully implements all mandatory physical layer requirements including LTSSM state transitions, electrical idle ordered sets, SKP symbol handling, and 8b/10b encoding/decoding. The PX1011B-EL1/G,551 does not support PCIe Gen 2 or later revisions, as its 2.5 Gbit/s data rate and timing architecture are fixed to Gen 1 specifications.

Does the PX1011B-EL1/G,551 integrate on-chip termination resistors for its PCIe differential I/O?

Yes, the PX1011B-EL1/G,551 integrates 50 Ω on-chip termination resistors for both the RX_P/RX_N and TX_P/TX_N differential pairs. This eliminates the need for external 50 Ω resistors on the PCB, simplifying layout and reducing component count. The termination is enabled automatically and cannot be disabled - it is optimized for standard PCIe AC-coupled interconnects with controlled impedance traces.

How does the PX1011B-EL1/G,551 handle clock tolerance between link partners?

The PX1011B-EL1/G,551 uses an elastic buffer capable of holding at least seven symbols to compensate for ±600 ppm frequency differences between link partners. When a Skip (SKP) ordered set is received, the PHY inserts or removes one SKP symbol as needed to prevent buffer overflow or underflow. This action is signaled to the MAC via the RXSTATUS[2:0] bus, enabling coordinated link-layer response - a core function implemented entirely in hardware within the PX1011B-EL1/G,551.

What is the purpose of the PWRDWN0 and PWRDWN1 pins on the PX1011B-EL1/G,551?

The PWRDWN0 and PWRDWN1 pins on the PX1011B-EL1/G,551 form a 2-bit encoded input that selects the PCIe power management state: 00b = P0 (normal operation), 01b = P0s (transmit idle), and 10b = P1 (full link idle). These pins directly control internal clock gating and block enablement per the PCIe specification. The PX1011B-EL1/G,551 asserts PHYSTATUS for one cycle upon successful state transition, providing deterministic handshaking with the MAC layer.

Can the PX1011B-EL1/G,551 operate with a non-spread-spectrum reference clock?

Yes, the PX1011B-EL1/G,551 operates reliably with a standard 100 MHz ±300 ppm reference clock without spread-spectrum modulation. Its PLL architecture accommodates both fixed-frequency and spread-spectrum inputs. While SSC is supported to reduce EMI, it is optional - the PX1011B-EL1/G,551 achieves full PCIe compliance and jitter performance using a clean 100 MHz clock, making it suitable for applications where SSC introduces timing complications or is prohibited by system-level EMI requirements.