Texas Instruments XIO2001ZAJ

Overview

XIO2001ZAJ from Texas Instruments is a single-function PCI Express to PCI bus translation bridge compliant with PCI Express Base Specification 2.0 and PCI Local Bus Specification 2.3. It provides full ×1 PCIe throughput (250 MB/s bidirectional), supports 32-bit/66-MHz PCI bus operation, and integrates an internal arbiter for up to six external PCI masters - enabling legacy PCI peripheral integration into modern PCIe-based industrial control and enterprise computing systems.

For engineers reviewing the XIO2001ZAJ datasheet, XIO2001ZAJ pinout, XIO2001ZAJ application, or XIO2001ZAJ equivalent, key selection considerations include its ZAJ nFBGA package (7.0 mm × 7.0 mm), dual-voltage PCI bus I/O tolerance (3.3-V/5.0-V), support for Active-State Power Management (L0s/L1), and configurable clock outputs (25/33/50/66 MHz).

Technical Context

The XIO2001ZAJ implements a robust pipeline architecture to minimize transaction latency between PCIe and PCI domains. It handles up to eight posted and four non-posted downstream transactions, and six posted and four non-posted upstream transactions simultaneously - preserving bandwidth across both interfaces.

It supports advanced error reporting including ECRC, PCI Express Data Poisoning, and PCI bus parity error forwarding. Its power management features include D1/D2/D3hot/D3cold states, CLKREQ-driven clock gating, and AUX power switching that drains VAUX only when main power is off.

Key Specifications

Pinout & Package

The XIO2001ZAJ is housed in a 144-ball ZAJ nFBGA package (7.0 mm × 7.0 mm) with 0.5-mm ball pitch. Ball mapping follows JEDEC MO-277, bottom-view orientation, and includes dedicated power/ground planes for signal integrity and thermal performance.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCI Express to PCI bridge applications.

Compared with PEX8112-CA33BC and PI7C9X2G304SV, the XIO2001ZAJ uniquely balances strict PCI 2.3 compliance, 5.0-V bus tolerance, compact ZAJ nFBGA footprint, and integrated AUX power management - making it optimal for industrial retrofit and space-constrained enterprise expansion where legacy PCI interoperability is mandatory.

Availability

XIO2001ZAJ is available at Aetrix Electronics and suitable for industrial control systems, enterprise server expansion, factory automation gateways, and retail payment terminal upgrades requiring stable component supply and long-term lifecycle support.

Supply support for XIO2001ZAJ 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

Texas Instruments is a global semiconductor leader specializing in analog, embedded processing, and connectivity technologies, with decades of expertise in high-reliability interface solutions.

The XIO2001ZAJ belongs to TI's PCI Express bridge product line, engineered specifically to enable seamless integration of legacy PCI peripherals into modern PCIe-based platforms across industrial, enterprise, and embedded applications.

FAQ

What is the primary function of the XIO2001ZAJ?

The XIO2001ZAJ is a single-function PCI Express to PCI bus translation bridge. Its primary function is to enable communication between a PCIe host (e.g., CPU chipset) and legacy PCI peripherals by converting PCIe packets to PCI transactions and vice versa - fully complying with PCI Express Base Specification 2.0 and PCI Local Bus Specification 2.3. The XIO2001ZAJ maintains full ×1 PCIe throughput (250 MB/s) and supports 32-bit/66-MHz PCI bus operation.

Does the XIO2001ZAJ support 5.0-V PCI bus signaling?

Yes, the XIO2001ZAJ supports 5.0-V PCI bus I/O signaling, but only at 25 MHz or 33 MHz clock rates - not at 66 MHz. This is enforced by the PCIR clamp rail configuration and documented in the device's electrical characteristics table. The XIO2001ZAJ achieves this through dedicated 5.0-V-tolerant PCI bus buffers and external resistor-based clamp voltage setting via the PCIR pins.

What reference clock options does the XIO2001ZAJ support?

The XIO2001ZAJ supports two reference clock configurations: a 100-MHz differential common reference clock (via REFCLK+/REFCLK− pins) or a 125-MHz single-ended reference clock (via REFCLK+ only, with REFCLK− tied to VSS). Selection is controlled by the REFCLK125_SEL pin. Spread spectrum clocking is also supported in both modes per PCIe specification requirements.

How many PCI clock outputs does the XIO2001ZAJ provide, and what frequencies are available?

The XIO2001ZAJ provides six buffered PCI clock outputs (CLKOUT0–CLKOUT6), configurable for 25 MHz, 33 MHz, 50 MHz, or 66 MHz operation. Frequency selection is determined by the M66EN and PCLK66_SEL pins, along with the REFCLK125_SEL setting. When using these outputs, CLKOUT6 must be connected to the CLK input pin to maintain proper PCI bus timing synchronization.

Is the XIO2001ZAJ pin-compatible with other packages in the XIO2001 family?

No, the XIO2001ZAJ (144-ball nFBGA) is not pin-compatible with the XIO2001ZWS (169-ball nFBGA) or XIO2001PNP (128-pin HTQFP) packages. Ball/pin assignments differ significantly across packages - for example, PERST# appears on H11 in ZAJ but on H11 in ZWS and pin 77 in PNP, while GPIO functions and clock outputs are mapped to distinct locations. Layout reuse requires package-specific footprint design.