AMD XCS40XL-4PQ208I

Overview

XCS40XL-4PQ208I from AMD (formerly Xilinx) is a Spartan-XL family FPGA with 40,000 system gates, 208-pin PQFP package, -4 speed grade, and industrial temperature range (–40°C to +100°C). It integrates configurable logic blocks, I/O banks supporting 3.3V LVTTL/LVCMOS, and dedicated carry logic for arithmetic functions - used in legacy industrial control interface modules.

For engineers reviewing the XCS40XL-4PQ208I datasheet, pinout, applications, or equivalent options, key selection criteria include gate count, I/O voltage compatibility, timing performance at –4 speed grade, and PQFP thermal and routing constraints in space-constrained PCBs.

Technical Context

The XCS40XL-4PQ208I implements a fine-grained architecture with CLBs containing four 3-input LUTs and flip-flops, distributed RAM capability up to 128 bits per CLB, and programmable interconnect with segmented routing channels. It supports in-system configuration via JTAG boundary-scan and serial PROM loading.

Its I/O structure includes programmable slew rate control, input hysteresis, and bus-hold circuitry on all user pins. The device lacks internal PLLs or DLLs and relies on external clock sources for synchronous design implementation.

Key Specifications

Pinout & Package

PQ208 package: 208-pin plastic quad flat pack with 0.5 mm lead pitch, exposed pad not present, JEDEC MS-026 compliant. Thermal resistance θ_JA = 42°C/W (typical, still-air).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FPGA logic implementation applications.

Compared with XCS40XL-4PQ208I, the XCS30XL-4PQ208I offers lower logic capacity but identical timing and packaging - suitable for cost-optimized derivatives; the XCS50XL-4PQ208I provides headroom for added functionality while maintaining pin and thermal compatibility.

Availability

XCS40XL-4PQ208I is available at Aetrix Electronics and suitable for industrial automation, legacy system repair, and test equipment manufacturing requiring stable component supply over extended product lifecycles.

Supply support for XCS40XL-4PQ208I 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

AMD acquired Xilinx in 2022 and now manages the legacy Spartan-XL product line. Xilinx pioneered FPGA architecture for reconfigurable digital logic before the acquisition.

The Spartan-XL family was designed for cost-sensitive, high-volume industrial and automotive applications requiring predictable timing, robust I/O, and long-term availability - not for high-performance computing or AI acceleration.

FAQ

What is the maximum operating frequency supported by the XCS40XL-4PQ208I?

The XCS40XL-4PQ208I has a -4 speed grade specifying guaranteed timing performance: maximum clock-to-output delay of 4.5 ns and setup time of 3.5 ns. This supports system clock frequencies up to approximately 125 MHz in well-designed synchronous paths, though actual achievable frequency depends on logic depth and routing congestion. The XCS40XL-4PQ208I does not include on-die PLLs, so external clock conditioning is required for jitter-sensitive applications.

Does the XCS40XL-4PQ208I support JTAG boundary-scan testing?

Yes, the XCS40XL-4PQ208I fully complies with IEEE 1149.1 (JTAG) for boundary-scan testing and in-system programming. Pins TMS, TCK, TDI, and TDO are dedicated for this purpose, with internal scan chain covering I/O cells and configuration logic. Pull-up resistors (10 kΩ) are required on TMS and TCK per Xilinx documentation for reliable operation. The XCS40XL-4PQ208I supports both programming and diagnostic modes via standard JTAG tools.

Can the XCS40XL-4PQ208I operate at 2.5V I/O voltage?

No, the XCS40XL-4PQ208I only supports 3.3V LVTTL and LVCMOS I/O standards. Its VCCO pins are rated for 3.3V ±10%, and the input thresholds are fixed for 3.3V logic families. Driving or receiving 2.5V signals directly risks incorrect logic interpretation or excessive input current. Level-shifting circuitry is required for interoperability with 2.5V systems. This limitation applies uniformly across all XCS40XL-4PQ208I units.

Is the XCS40XL-4PQ208I RoHS compliant?

The XCS40XL-4PQ208I was originally manufactured prior to full RoHS enforcement and is classified as a legacy non-RoHS part. It contains lead in the PQ208 package solder finish and die attach material. AMD/Xilinx does not offer a RoHS-compliant variant of this specific speed-grade/package combination. For new designs requiring RoHS compliance, migration to Spartan-3 or later families is recommended. The XCS40XL-4PQ208I remains available for legacy repair and obsolescence management.

How is configuration data loaded into the XCS40XL-4PQ208I?

Configuration data for the XCS40XL-4PQ208I is loaded either through JTAG (using TMS/TCK/TDI/TDO) or via a serial PROM connected to the dedicated configuration interface pins (e.g., DIN, CCLK, PROGRAM*). The device uses SRAM-based configuration memory, meaning it must be reloaded at power-up. External PROMs such as Xilinx XC18V02 or compatible 2-Mbit serial EEPROMs are commonly used. The XCS40XL-4PQ208I does not support master-mode configuration or internal flash storage.