The XC3S400-5TQ144C is a high-performance, cost-optimized Field-Programmable Gate Array (FPGA) from Xilinx’s Spartan-3 family. Manufactured using advanced 90nm process technology and operating at a core voltage of 1.2V, this device delivers 400,000 system gates within a compact 144-pin TQFP package — making it an ideal solution for high-volume, cost-sensitive embedded and consumer electronics applications.
Whether you are designing digital signal processing pipelines, communications interfaces, or complex control logic, the XC3S400-5TQ144C provides the programmability, performance, and logic density to meet your design requirements.
What Is the XC3S400-5TQ144C?
The XC3S400-5TQ144C belongs to Xilinx’s Spartan-3 FPGA family, which builds on the success of the earlier Spartan-IIE series. The “5” in the part number indicates the speed grade (fastest available for this family), “TQ144” refers to the 144-pin Thin Quad Flat Pack (TQFP) package, and “C” denotes commercial temperature range (0°C to +85°C).
As a Xilinx FPGA, the XC3S400-5TQ144C supports in-field design updates with no hardware replacement required — a critical advantage over mask-programmed ASICs that eliminates lengthy development cycles and inflexible fixed designs.
XC3S400-5TQ144C Key Specifications
| Parameter |
Value |
| Manufacturer |
Xilinx (AMD) |
| Part Number |
XC3S400-5TQ144C |
| FPGA Family |
Spartan-3 |
| System Gates |
400,000 |
| Logic Cells (CLBs) |
8,064 |
| Configurable Logic Blocks (CLBs) |
896 |
| CLB Array |
32 × 28 |
| Flip-Flops |
7,168 |
| Distributed RAM |
56 Kbits |
| Block RAM |
288 Kbits |
| Block RAM Blocks |
16 |
| Dedicated Multipliers (18×18) |
16 |
| Digital Clock Managers (DCMs) |
4 |
| Maximum System Frequency |
725 MHz |
| Process Technology |
90nm CMOS |
| Core Supply Voltage (VCCINT) |
1.2V |
| I/O Supply Voltage (VCCO) |
1.2V – 3.3V |
| Max User I/O Pins (TQ144) |
97 |
| Package |
144-Pin TQFP (Thin Quad Flat Pack) |
| Package Body Size |
20mm × 20mm |
| Temperature Range |
Commercial: 0°C to +85°C |
| Speed Grade |
–5 (Fastest) |
| RoHS Compliance |
Non-compliant (standard Pb package) |
| Configuration Storage |
External PROM or nonvolatile medium |
XC3S400-5TQ144C Functional Architecture
Configurable Logic Blocks (CLBs)
The XC3S400-5TQ144C contains 896 CLBs arranged in a 32 × 28 array, each consisting of four slices. Every slice contains two 4-input Look-Up Tables (LUTs), two storage elements (flip-flops or latches), and dedicated carry and arithmetic logic. The equivalent logic cell count reaches 8,064, providing substantial design capacity for complex digital functions.
Block RAM and Distributed RAM
The device includes 16 block RAM modules, each 18 Kbits in size, totaling 288 Kbits of dedicated on-chip memory. This block RAM supports true dual-port operation, making it ideal for FIFOs, data buffers, and lookup tables. Additionally, 56 Kbits of distributed RAM is available within the CLB LUT resources.
Dedicated Multipliers
Sixteen 18×18-bit dedicated hardware multipliers are included, each paired with a block RAM module. This pairing enables efficient DSP operations such as digital filtering, correlation, and multiply-accumulate functions — without consuming general-purpose logic resources.
Digital Clock Managers (DCMs)
Four Digital Clock Managers provide clock synthesis, phase shifting, frequency multiplication, and frequency division. The DCMs enable precise clock domain management across complex multi-clock designs, supporting reliable high-speed interfaces.
I/O Block (IOB) Architecture
Each IOB contains input, output, and 3-state paths, each with dedicated storage elements (registers or latches). The device supports Double Data Rate (DDR) input/output, enabling high-speed data transfer on both clock edges.
XC3S400-5TQ144C I/O Standards Support
The 144-pin TQFP package provides up to 97 user I/O pins organized into multiple banks. The following I/O standards are supported:
| I/O Standard |
Type |
Notes |
| LVCMOS 3.3V / 2.5V / 1.8V / 1.5V |
Single-ended |
Widely compatible |
| LVTTL |
Single-ended |
3.3V logic standard |
| SSTL2 Class I/II |
Single-ended differential |
DDR memory interfaces |
| SSTL18 Class I |
Single-ended |
DDR2 applications |
| HSTL Class I/III/IV |
Single-ended |
High-speed termination |
| LVDS |
Differential |
High-speed serial |
| LVPECL |
Differential |
Clock/data transmission |
| BLVDS |
Differential |
Bus LVDS |
Note: DCI (Digitally Controlled Impedance) signal standards are not supported in the TQ144 package.
XC3S400-5TQ144C Configuration Modes
Spartan-3 FPGAs store configuration data externally and load it into reprogrammable CMOS Configuration Latches (CCLs) on power-up. The XC3S400-5TQ144C supports five configuration modes:
| Configuration Mode |
Description |
| Master Parallel |
FPGA drives address bus; reads from parallel PROM |
| Slave Parallel |
External controller drives address and data |
| Master Serial |
FPGA drives clock; reads serial bit stream |
| Slave Serial |
External controller drives clock and data |
| JTAG / Boundary Scan |
IEEE 1149.1 compliant in-circuit programming |
The recommended companion PROM for the XC3S400 is the XCF02S (1.7 Mbit capacity).
XC3S400-5TQ144C Ordering Information and Part Number Decoder
Understanding the part number helps select the correct variant for your design:
| Field |
Code |
Meaning |
| Device |
XC3S400 |
Spartan-3, 400K gates |
| Speed Grade |
-5 |
Fastest commercial grade |
| Package |
TQ |
Thin Quad Flat Pack (TQFP) |
| Pin Count |
144 |
144 pins |
| Temperature |
C |
Commercial (0°C to +85°C) |
Related variants:
| Part Number |
Package |
Pins |
User I/O |
Temp Grade |
| XC3S400-5TQ144C |
TQFP |
144 |
97 |
Commercial |
| XC3S400-5TQ144I |
TQFP |
144 |
97 |
Industrial |
| XC3S400-5TQG144C |
TQFP (Pb-free) |
144 |
97 |
Commercial |
| XC3S400-5PQ208C |
PQFP |
208 |
141 |
Commercial |
| XC3S400-5FT256C |
FTBGA |
256 |
173 |
Commercial |
XC3S400-5TQ144C vs. Other Spartan-3 Devices
| Device |
System Gates |
Logic Cells |
Block RAM |
Multipliers |
Max I/O |
| XC3S50 |
50K |
1,728 |
72 Kbits |
4 |
124 |
| XC3S200 |
200K |
4,320 |
216 Kbits |
12 |
173 |
| XC3S400 |
400K |
8,064 |
288 Kbits |
16 |
264 |
| XC3S1000 |
1000K |
17,280 |
432 Kbits |
24 |
391 |
| XC3S1500 |
1500K |
29,952 |
576 Kbits |
32 |
487 |
The XC3S400 occupies the mid-range of the Spartan-3 family, offering a strong balance of logic density, memory, and DSP resources at a cost-effective price point.
Typical Applications for the XC3S400-5TQ144C
The XC3S400-5TQ144C is well suited for a broad range of embedded design applications:
- Digital Signal Processing (DSP): FIR/IIR filters, FFT engines, and audio/video processing using dedicated multipliers and block RAM
- Communications Interfaces: UART, SPI, I²C, and parallel bus controllers
- Industrial Control Systems: Motor control, sensor data acquisition, and state machine logic
- Consumer Electronics: Set-top boxes, flat panel display controllers, and handheld devices
- Prototyping and ASIC Replacement: Rapid prototyping of logic functions traditionally implemented in ASICs
- Embedded Microcontroller Systems: Soft-core processor implementations (e.g., PicoBlaze, MicroBlaze)
- Glue Logic Replacement: Consolidating multiple discrete logic ICs into a single programmable device
Design Tool Support
The XC3S400-5TQ144C is supported by Xilinx’s legacy ISE Design Suite, which provides synthesis, implementation, simulation, and programming tools. Designers working on modern flows may also reference Vivado for migration planning. HDL support includes both VHDL and Verilog.
For device configuration, the iMPACT programmer or compatible third-party JTAG tools are used to download bitstream files into the FPGA or companion PROM.
Package Dimensions: 144-Pin TQFP
| Parameter |
Value |
| Package Type |
TQFP (Thin Quad Flat Pack) |
| Total Pin Count |
144 |
| Body Size |
20mm × 20mm |
| Lead Pitch |
0.5mm |
| Package Height |
~1.4mm |
| Mounting Type |
Surface Mount |
The compact 20mm × 20mm body and fine 0.5mm lead pitch make the TQ144 package suitable for space-constrained PCB designs while remaining hand-solderable for prototyping.
Frequently Asked Questions (FAQ)
Q: What is the difference between XC3S400-5TQ144C and XC3S400-5TQG144C? The “G” in XC3S400-5TQG144C indicates a Pb-free (RoHS-compliant) package. Both devices are functionally and electrically identical.
Q: What external PROM is recommended for configuring the XC3S400? Xilinx recommends the XCF02S (1.7 Mbit) Platform Flash PROM for configuring the XC3S400 family devices.
Q: Does the TQ144 package support DCI I/O standards? No. Digitally Controlled Impedance (DCI) is not available in the TQ144 or VQ100 packages of the Spartan-3 family.
Q: What programming software supports the XC3S400-5TQ144C? Xilinx ISE Design Suite (including iMPACT) is the primary tool. JTAG-based third-party programmers compatible with Xilinx Spartan-3 are also widely available.
Q: Is the XC3S400-5TQ144C in production? The Spartan-3 family is considered a mature product line. While no longer in active development, stock is available through authorized distributors. Consult your distributor for lead times and long-term availability.
