AMD XC3S400-5FT256C

Overview

XC3S400-5FT256C from AMD (formerly Xilinx) is a Spartan-3 FPGA with 400,000 system gates, 241 I/O pins, and a 5 ns logic delay grade in a 256-pin Fine-Pitch Ball Grid Array (FBGA) package. It integrates up to 22 dedicated multipliers, 1728 CLBs, and supports LVCMOS25/LVCMOS33 I/O standards for embedded control and digital logic acceleration.

For engineers reviewing the XC3S400-5FT256C datasheet, pinout, applications, or equivalent options, key selection factors include logic capacity, I/O voltage flexibility, embedded multiplier count, and industrial temperature range operation.

Technical Context

The XC3S400-5FT256C implements a configurable logic fabric based on 4-input LUTs and flip-flops per CLB, with distributed RAM and shift register capability per slice. It includes eight global clock networks and supports Digital Clock Managers (DCMs) for input clock multiplication, division, phase shifting, and duty cycle correction.

Configuration is performed via Master Serial mode using an external PROM or through JTAG boundary-scan. The device supports IEEE 1149.1 compliance and includes internal configuration monitoring with CRC checking to ensure bitstream integrity during power-up.

Key Specifications

Pinout & Package

XC3S400-5FT256C is housed in a 256-ball Fine-Pitch Ball Grid Array (FTBGA) package with 17×17 array, 1.0 mm ball pitch, and thermal pad exposed on underside. Pinout follows Xilinx Spartan-3 family standard layout with dedicated configuration, JTAG, clock, and I/O banks grouped by voltage domain.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC3S500E-5FT256C and XC3S200-5FT256C, the XC3S400-5FT256C delivers balanced logic density, I/O count, and DSP resource allocation for mid-complexity embedded control-making it optimal for applications requiring deterministic timing and moderate algorithmic throughput without over-provisioning.

Availability

XC3S400-5FT256C is available at Aetrix Electronics and suitable for industrial motion control, automated test equipment, and medical imaging interface designs requiring stable component supply and long-term manufacturability.

Supply support for XC3S400-5FT256C 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 supports the Spartan, Artix, Kintex, and Virtex FPGA families for adaptive computing solutions.

The Spartan-3 family, including XC3S400-5FT256C, was designed for cost-sensitive, high-volume embedded applications requiring reliable programmable logic with integrated clock management and flexible I/O.

FAQ

What is the maximum operating frequency of the XC3S400-5FT256C?

The XC3S400-5FT256C has a -5 speed grade, specifying a worst-case T_PD of 5 ns for internal logic paths. Its maximum system clock frequency depends on design implementation but typically reaches 280 MHz for register-to-register paths and 120 MHz for full-system operation with routing and I/O constraints. The DCMs support input frequencies up to 240 MHz and output frequencies up to 320 MHz.

Does the XC3S400-5FT256C support JTAG programming?

Yes, the XC3S400-5FT256C fully supports IEEE 1149.1 JTAG boundary-scan for programming, debugging, and interconnect testing. Pins TCK, TMS, TDI, and TDO are dedicated for this function and can be used to configure the device or perform in-system verification without requiring external configuration PROMs.

What I/O standards are supported by the XC3S400-5FT256C?

The XC3S400-5FT256C supports LVCMOS12, LVCMOS15, LVCMOS18, LVCMOS25, LVCMOS33, LVTTL, PCI, SSTL2_I, SSTL3_I, and HSTL_I standards across its eight configurable I/O banks. Each bank operates at a single V_CCO voltage, allowing mixed-voltage interface coexistence on one device.

Is the XC3S400-5FT256C RoHS compliant?

Yes, the XC3S400-5FT256C is RoHS compliant and lead-free, meeting EU Directive 2011/65/EU requirements. The FT256 package uses matte tin finish on solder balls and complies with JEDEC J-STD-020 moisture sensitivity level 3 (MSL3) handling guidelines.

Can the XC3S400-5FT256C be reconfigured in-system?

Yes, the XC3S400-5FT256C supports in-system reconfiguration via JTAG or Master Serial mode. The PROG_B pin allows hardware-triggered reconfiguration, and the ICAP (Internal Configuration Access Port) enables partial reconfiguration of logic sections while other portions remain operational-a capability confirmed in Xilinx UG332 documentation.