AMD XC3S400-5PQG208C

Overview

XC3S400-5PQG208C 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 208-pin PQFP package. It integrates up to 228 configurable logic blocks (CLBs), 176 Kbits of block RAM, and supports LVCMOS25/LVCMOS33 I/O standards for embedded control and interface bridging applications.

For engineers reviewing the XC3S400-5PQG208C datasheet, pinout, applications, or equivalent options, key selection factors include logic density, I/O voltage compatibility, internal RAM capacity, and timing performance at industrial temperature range.

Technical Context

The XC3S400-5PQG208C implements a hierarchical FPGA architecture with configurable logic blocks, distributed RAM, and dedicated multipliers. It supports SelectIO technology for programmable I/O standards including LVTTL, LVCMOS, PCI, and SSTL.

Configuration is performed via master serial mode using external PROM or JTAG boundary-scan. The device operates across –40°C to +85°C and requires separate VCCINT (1.2 V), VCCAUX (3.3 V), and VCCO (1.2–3.3 V) supplies.

Key Specifications

Pinout & Package

XC3S400-5PQG208C is housed in a 208-pin Plastic Quad Flat Package (PQFP) with 28 × 28 mm body size, 0.5 mm lead pitch, and exposed thermal pad. Pinout conforms to Xilinx Spartan-3 family standard layout for PQFP packages.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XC3S400-5PQG208C, the XC3S500E-5PQG208C offers headroom for future feature expansion, while the XC3S200-5PQG208C reduces BOM cost where logic utilization stays below 50% - both share identical footprint and thermal profile.

Availability

XC3S400-5PQG208C is available at Aetrix Electronics and suitable for industrial motion control, medical imaging data acquisition, and legacy bus interface bridge applications requiring stable component supply and long-term lifecycle support.

Supply support for XC3S400-5PQG208C 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 maintains the Spartan-3 product line for industrial and legacy system support. Xilinx pioneered FPGA architecture and programmable logic solutions.

The Spartan-3 family was designed for cost-sensitive, high-volume applications requiring reliable programmable logic with integrated I/O and memory resources - targeting industrial control, test equipment, and communication interfaces.

FAQ

What is the maximum operating frequency of the XC3S400-5PQG208C?

The XC3S400-5PQG208C has a -5 speed grade specifying a 5 ns CLB propagation delay. Its maximum system clock frequency depends on design topology but typically supports synchronous logic up to 200 MHz in well-constrained implementations. The device includes eight global clock networks optimized for low skew across the die, and its DCM (Digital Clock Manager) supports frequency synthesis and phase shifting for timing closure.

Does the XC3S400-5PQG208C support JTAG programming?

Yes, the XC3S400-5PQG208C fully supports IEEE 1149.1 JTAG boundary-scan for configuration, debugging, and interconnect testing. Pins TCK, TMS, TDI, and TDO are dedicated for this purpose, and the device can be programmed in-system without requiring external configuration PROM. JTAG mode is selected by setting M0–M2 pins to 010 at power-up.

What power supplies are required for the XC3S400-5PQG208C?

The XC3S400-5PQG208C requires three independent supply voltages: VCCINT = 1.2 V ±3% for core logic, VCCAUX = 3.3 V ±5% for auxiliary circuits including DCM and JTAG, and VCCO = 1.2–3.3 V (per I/O bank) for output drivers. Each supply must be decoupled with appropriate ceramic capacitors close to respective power pins to ensure stable operation across the industrial temperature range.

Can the XC3S400-5PQG208C be used in automotive applications?

No, the XC3S400-5PQG208C is rated for industrial temperature range (–40°C to +85°C) and is not qualified to AEC-Q100 or other automotive reliability standards. It lacks automotive-grade screening, extended temperature testing, and failure rate documentation required for under-hood or safety-critical vehicle systems. For automotive use, consider AMD/Xilinx Automotive Spartan-3A or newer families.

Is the XC3S400-5PQG208C pin-compatible with other Spartan-3 PQFP devices?

Yes, the XC3S400-5PQG208C shares identical 208-pin PQFP mechanical footprint and pin assignment with XC3S200-5PQG208C and XC3S500E-5PQG208C. All three support the same I/O bank structure, power pin locations, and configuration interface layout - enabling direct PCB reuse when upgrading or downgrading logic density within the same package variant.