AMD XC3S400A-4FGG400I

Overview

XC3S400A-4FGG400I from AMD (formerly Xilinx) is a Spartan-3A FPGA with 400,000 system gates, 8,064 logic cells, and 216 I/O pins in a 400-pin Fine-Pitch Ball Grid Array (FBGA) package. It operates at -4 speed grade (tPD = 4.5 ns), supports SelectIO™ standards up to 622 Mbps, and targets cost-sensitive embedded control and interface bridging applications.

For engineers reviewing the XC3S400A-4FGG400I datasheet, pinout, applications, or equivalent options, key selection criteria include I/O voltage flexibility (1.2 V to 3.3 V), embedded block RAM capacity (216 Kbits), and support for DDR/DDR2 SDRAM interfaces in industrial automation and communications hardware.

Technical Context

The XC3S400A-4FGG400I implements a configurable logic fabric based on 4-input LUTs and flip-flops, with dedicated carry logic for arithmetic operations. It integrates twelve 18×18 multipliers and eight Digital Clock Managers (DCMs) supporting phase shifting, frequency synthesis, and duty cycle correction.

Configuration is performed via Master Serial mode using external PROM or microcontroller-driven JTAG. The device supports IEEE 1149.1 boundary-scan testing and includes internal configuration monitoring with CRC error detection.

Key Specifications

Pinout & Package

XC3S400A-4FGG400I is housed in a 400-ball Fine-Pitch BGA (FBGA) package with 1.0 mm ball pitch, 21 mm × 21 mm body size, and RoHS-compliant lead-free finish. Thermal performance supports operation from –40°C to +100°C junction temperature.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC3S400A-4FGG400I, the XC3S500A-4FGG400I offers headroom for future feature expansion within the same PCB layout, while the XC3S200A-4FTG256C trades I/O count and logic capacity for simplified manufacturing and lower BOM cost in less demanding applications.

Availability

XC3S400A-4FGG400I is available at Aetrix Electronics and suitable for industrial automation, medical imaging hardware, and telecom infrastructure requiring stable component supply across extended product lifecycles.

Supply support for XC3S400A-4FGG400I 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 develops and markets adaptive computing platforms including FPGAs, adaptive SoCs, and AI accelerators.

The Spartan-3A family was originally designed by Xilinx for cost-optimized, high-volume embedded applications requiring reliable I/O flexibility and moderate logic density without advanced transceivers.

FAQ

What is the maximum operating frequency supported by XC3S400A-4FGG400I?

The XC3S400A-4FGG400I is rated for a maximum system clock frequency of 280 MHz under worst-case conditions, as guaranteed by its -4 speed grade. This applies to internal logic paths meeting timing constraints after place-and-route; actual achievable frequency depends on design complexity, routing congestion, and I/O standard selection. The device's eight Digital Clock Managers support output frequencies up to 320 MHz through multiplication, but internal logic timing remains bound by the -4 grade specification.

Does XC3S400A-4FGG400I support JTAG boundary-scan testing?

Yes, XC3S400A-4FGG400I fully complies with IEEE 1149.1 and supports boundary-scan testing via its dedicated TDI, TDO, TMS, and TCK pins. The JTAG chain can configure the device, perform interconnect testing, and access internal debug registers. All I/O pins are accessible through the boundary-scan register, enabling verification of solder joints and PCB trace integrity before functional programming of the XC3S400A-4FGG400I.

Can XC3S400A-4FGG400I interface directly with DDR2 SDRAM?

Yes, XC3S400A-4FGG400I supports DDR2 SDRAM interfacing using its SelectIO technology and built-in DCMs for clock deskewing. It meets SSTL_18 I/O standards required for DDR2, and its 216 I/O pins allow full address/data bus implementation. However, it lacks dedicated DDR2 PHY logic, so timing-critical operations like read/write leveling must be implemented in fabric logic, and careful PCB layout with matched trace lengths is required for reliable operation at speeds up to 400 Mbps.

What configuration modes are supported by XC3S400A-4FGG400I?

XC3S400A-4FGG400I supports Master Serial (via external SPI PROM), Slave Serial, JTAG, and Boundary Scan configuration modes. Master Serial is most common for production systems, using a Xilinx-compatible PROM such as XC18V02. JTAG is used for development and debugging. Configuration occurs on power-up or after PROGRAM_B assertion, and the DONE pin signals completion. Bitstream encryption is optional and requires an external PROM with security key support.

Is XC3S400A-4FGG400I RoHS compliant and lead-free?

Yes, XC3S400A-4FGG400I is RoHS compliant and features a lead-free, matte tin finish on all 400 solder balls. The FBGA package meets JEDEC J-STD-020 moisture sensitivity level 3 (MSL3), requiring bake conditioning if exposed to ambient for more than 168 hours before reflow. Full compliance documentation, including substance declarations and test reports, is available from AMD's official product change notifications for the Spartan-3A family.