AMD XC3S400A-5FTG256C

Overview

XC3S400A-5FTG256C from AMD (formerly Xilinx) is a Spartan-3A FPGA with 400,000 system gates, 216 I/O pins, and a 5 ns logic delay grade in a 256-pin Fine-Pitch Thin Quad Flatpack (FTBGA) package. It integrates 8,064 logic cells, 288 Kbits of block RAM, and supports LVCMOS25/LVCMOS33 I/O standards for embedded control and interface bridging applications.

For engineers reviewing the XC3S400A-5FTG256C datasheet, pinout, applications, or equivalent options, key selection criteria include logic cell count, I/O voltage compatibility, block RAM depth, configuration mode support (Master Serial, Slave SelectMAP), and thermal performance in industrial temperature range operation.

Technical Context

The XC3S400A-5FTG256C implements a fully reconfigurable logic fabric based on 4-input LUTs and distributed RAM, with dedicated carry logic for arithmetic functions. It includes twelve 18×18 multipliers and supports DDR/DDR2 SDRAM interfaces up to 333 Mbps.

Configuration is performed via JTAG, Master Serial (SPI PROM), or Slave SelectMAP modes. The device uses internal voltage regulation (VCCINT = 1.2 V) and supports dual-supply I/O banks (VCCO = 1.2 V to 3.3 V) with programmable slew rate and drive strength per bank.

Key Specifications

Pinout & Package

XC3S400A-5FTG256C is housed in a 256-pin Fine-Pitch Thin Ball Grid Array (FTBGA) package with 1.0 mm ball pitch and 17 × 17 array. Thermal pad on underside improves power dissipation during sustained logic activity.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FPGA-based interface and control applications.

Compared with XC3S400A-5FTG256C, XC3S500E-4FG320C offers greater logic capacity at the expense of I/O versatility, while XC6SLX9-2TQG144C trades I/O count and density for smaller size and DSP capability-making each suitable only where their specific trade-offs align with system architecture requirements.

Availability

XC3S400A-5FTG256C is available at Aetrix Electronics and suitable for industrial automation, medical imaging, and automotive ADAS applications requiring stable component supply and long-term design-in support.

Supply support for XC3S400A-5FTG256C 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 continues development of its FPGA portfolio. Xilinx pioneered SRAM-based reconfigurable logic and introduced the Spartan family for cost-sensitive, high-volume applications.

The Spartan-3A product line was designed for embedded control, interface bridging, and digital signal preprocessing in industrial, medical, and test equipment where predictable timing and I/O flexibility are critical.

FAQ

What is the configuration method supported by XC3S400A-5FTG256C?

The XC3S400A-5FTG256C supports three primary configuration methods: Master Serial (using an external SPI PROM), Slave SelectMAP (for parallel loading from a microcontroller), and JTAG (for programming and debugging). All methods are implemented in hardware and require no firmware overhead. XC3S400A-5FTG256C configuration occurs automatically on power-up when Master Serial mode is selected, making it ideal for unattended industrial systems.

Does XC3S400A-5FTG256C support LVDS signaling natively?

Yes, XC3S400A-5FTG256C supports LVDS I/O standards natively through its SelectI/O technology, with guaranteed performance up to 622 Mbps per differential pair. This capability is verified in the Xilinx DS312 datasheet and applies directly to pins configured in LVDS mode within compatible I/O banks. XC3S400A-5FTG256C does not require external termination resistors for standard LVDS operation.

What is the operating voltage requirement for XC3S400A-5FTG256C core and I/O supplies?

XC3S400A-5FTG256C requires a regulated 1.2 V supply for VCCINT (core logic) and configurable I/O supply voltages from 1.2 V to 3.3 V per bank (VCCO). Each I/O bank must have its own VCCO rail, and unused banks must be tied to a valid voltage or grounded per Xilinx guidelines. XC3S400A-5FTG256C specification compliance depends on maintaining ±3% tolerance on VCCINT and ±5% on VCCO.

Can XC3S400A-5FTG256C be used in automotive applications?

XC3S400A-5FTG256C is rated for 0°C to 85°C operation and is not AEC-Q100 qualified. It has been deployed in non-safety-critical automotive subsystems such as infotainment and camera hubs where environmental stress is managed externally. XC3S400A-5FTG256C lacks built-in safety mechanisms like SEU mitigation or lockstep logic, so it is not recommended for ASIL-B or higher applications without supplemental system-level fault handling.

How many Digital Clock Managers (DCMs) are included in XC3S400A-5FTG256C?

XC3S400A-5FTG256C contains four fully independent Digital Clock Managers (DCMs), each capable of frequency synthesis, phase shifting, duty cycle correction, and clock doubling. These DCMs operate without external components and support input frequencies from 5 MHz to 200 MHz. XC3S400A-5FTG256C uses them to generate synchronized clocks for multiple peripherals, reducing jitter-sensitive timing paths in high-speed interface designs.