NXP Semiconductors PX1011B-EL1/N,557

Overview

PX1011B-EL1/N,557 from NXP Semiconductors is a single-lane, 2.5 Gbit/s PCI Express Base Specification Rev. 1.1-compliant physical layer (PHY) IC with Clock and Data Recovery (CDR), 8b/10b encoding/decoding, elastic buffer, and SSTL_2 8-bit PXPIPE interface operating at 250 MHz. It serves as a stand-alone X1 PHY between MAC and PCIe serial link in FPGA-based embedded systems requiring low-power, industrial-grade interconnect.

For engineers reviewing the PX1011B-EL1/N,557 datasheet, PX1011B-EL1/N,557 pinout, PX1011B-EL1/N,557 application, or PX1011B-EL1/N,557 equivalent, key selection criteria include its LFBGA81 package, 2.5 V SSTL_2 I/O compatibility with FPGAs, support for P0/P0s/P1 power states, JTAG boundary scan, and differential PCIe I/O with on-chip 50 Ω termination.

Technical Context

The PX1011B-EL1/N,557 implements a full SerDes architecture with separate CDR and PLL blocks: REFCLK_P/N (100 MHz ±300 ppm) drives internal clock generation, while TXCLK (250 MHz source-synchronous input) and RXCLK (250 MHz source-synchronous output) synchronize parallel data transfers. Its PCS layer performs 8b/10b encode/decode, comma detection (K28.5), and disparity control.

Power management is implemented via PWRDWN[1:0] inputs controlling P0/P0s/P1 states; receiver detection and loopback are triggered by RXDET_LOOPB; and electrical idle is enforced via TXIDLE. All status reporting-including SKP insertion/removal, receiver presence, and 8b/10b decode errors-is conveyed through three-bit RXSTATUS outputs synchronized to RXCLK.

Key Specifications

Pinout & Package

LFBGA81 package: plastic low-profile fine-pitch ball grid array, 9 × 9 × 1.05 mm body, 81 solder balls, SnPb solder ball compound (per ordering code -EL1/N).

Key Features

Applications

Equivalent & Alternatives

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

Compared with PX1011B-EL1/N,557, IDT8N34S2108BKILF offers integrated clock synthesis but less flexible receiver detection, while TSB530 reduces power consumption at the expense of spread-spectrum and JTAG test capability-making PX1011B-EL1/N,557 optimal for FPGA-centric designs needing full PCIe 1.1 compliance and debug visibility.

Availability

PX1011B-EL1/N,557 is available at Aetrix Electronics and suitable for FPGA-based PCIe interconnect, industrial embedded controllers, and test equipment requiring stable component supply with SnPb solder compatibility and commercial temperature grading.

Supply support for PX1011B-EL1/N,557 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 product line delivers stand-alone PCIe Gen1 physical layer ICs optimized for FPGA interfacing, low-power operation, and robust signal integrity in space-constrained embedded systems.

FAQ

What PCIe specification revision does the PX1011B-EL1/N,557 support?

The PX1011B-EL1/N,557 supports PCI Express Base Specification Revision 1.1. It is fully compliant with all mandatory physical layer requirements including link training, electrical idle, 8b/10b encoding, and LTSSM state transitions. The device does not support PCIe Gen2 or later revisions, and its 2.5 Gbit/s data rate is fixed to Gen1 speed.

Does the PX1011B-EL1/N,557 include on-chip termination for its PCIe differential I/O?

Yes, the PX1011B-EL1/N,557 includes 50 Ω on-chip termination for both RX_P/RX_N and TX_P/TX_N differential pairs. This eliminates the need for external termination resistors on the PCB, simplifying layout and improving signal integrity for the 2.5 Gbit/s PCIe link. Termination is enabled automatically and cannot be disabled.

What is the function of the RXDET_LOOPB pin on the PX1011B-EL1/N,557?

The RXDET_LOOPB pin on the PX1011B-EL1/N,557 serves a dual function: when asserted (LOW), it initiates either receiver detection (to verify presence of a downstream PCIe device) or internal loopback mode (to route received data back to the transmitter). The PHY distinguishes between these operations based on current power state and other control signals like PWRDWN[1:0].

Can the PX1011B-EL1/N,557 operate with a 3.3 V core supply?

No, the PX1011B-EL1/N,557 requires a 1.2 V core supply (VDDD3) as specified in Table 12. Its digital core logic is designed for 1.2 V operation, and applying 3.3 V to VDDD3 pins will cause permanent damage. Only VDDD1 (JTAG I/O) accepts 3.3 V; all other supplies have strict voltage ranges: VDDD2 = 2.5 V ±0.2 V, VDDA1 = 1.2 V ±0.1 V, etc.

How does the PX1011B-EL1/N,557 handle clock tolerance between link partners?

The PX1011B-EL1/N,557 uses an elastic buffer capable of holding at least seven symbols to absorb ±600 ppm frequency differences. When SKP ordered sets are received, the PHY inserts or removes individual SKP symbols and signals the action via RXSTATUS[2:0] - enabling the MAC to maintain data alignment without requiring precise clock synchronization between endpoints.