LFE5U-25F-8BG381C is a Lattice ECP5 FPGA with a 24K-LUT fabric and 197 user I/O in a 381-ball caBGA package. It is a candidate for parallel digital interfaces, control logic and bounded signal-processing pipelines. The LFE5U variant has no embedded SERDES; PCIe, SGMII or CPRI transceiver capability must not be inferred from an ECP5 family description.
Technical reference updated October 19, 2026. Electrical values below refer to the manufacturer documents listed at the end.
Identify the complete order code
Use LFE5U-25F-8BG381C on the BOM and quotation request. “ECP5-25F-8BG381C” describes a family and size informally but omits the device-family prefix that distinguishes LFE5U from LFE5UM and LFE5UM5G. The commercial ordering table explicitly lists the complete code. The -8 denotes the fastest of the listed -6, -7 and -8 speed grades; BG381 identifies the lead-free caBGA package; C selects the commercial grade.
| LUT capacity | 24K, as reported in the family selection table |
|---|---|
| Embedded block memory | 56 blocks of 18 kb; 1,008 kb total |
| Distributed RAM | 194 kb, listed separately from embedded memory |
| 18 × 18 multipliers | 28 dedicated units |
| PLLs / DLLs | 2 / 2 |
| BG381 user I/O | 197; shared-function pins require a configuration plan |
| Embedded SERDES | None |
| Package body and pitch | 17 × 17 mm; 0.8 mm ball pitch |
| Commercial operating junction temperature | 0°C to +85°C |
These are device resources from Table 1.1 of the family data sheet, not a guarantee that every resource can run at a single advertised clock frequency. Actual fit and speed depend on the routed design, constraints and operating corner.
Make the pin budget before choosing the board footprint
The 381 balls include power, grounds, configuration signals and other dedicated functions. They are not 381 general-purpose connections. Start a pin spreadsheet from the ECP5U-25 pinout and use its 381-ball column. Record each signal's bank, direction, I/O standard, voltage, clock requirement and use during configuration. Reserve boot and debug access before assigning application buses.
For a concrete migration check, Lattice's caBGA381 migration table labels ball A4 as PL2A with no listed dual function on the 25F, while the 45F and 85F entries label A4 as PL11A with ULC_GPLL0T_IN. That difference is a reason to check the actual signal functions on every used ball before changing density.
For a differential input, check the actual pair and bank capabilities rather than treating two spare GPIO as a validated differential interface. A nominal VCCIO range does not establish direct compatibility with every sensor or processor. Compare the chosen standard's input thresholds, output levels and bank restrictions with both endpoints. A MIPI camera connection additionally needs an appropriate electrical implementation and protocol logic; a LUT count alone cannot establish D-PHY compliance.
Power and configuration decisions
The recommended ECP5 core rail is 1.1 V nominal, with a 1.045–1.155 V operating range. VCCAUX is 2.5 V nominal, with a 2.375–2.625 V range. VCCIO follows the selected bank standards. Keep these domains distinct in the schematic and use the supply-ramp and power-on-reset requirements in the data sheet. The hardware checklist provides decoupling and filter guidance; adapt its network to the board's load, regulator and placement instead of treating a short capacitor list as a completed power design.
Configuration is SRAM based. A standalone design can load a bitstream from compatible external SPI flash; a host can provide configuration through a supported interface, and JTAG is useful for development and diagnosis. Decide how the board reaches its bitstream after every power cycle. Check configuration-bank voltage, mode straps, PROGRAMN, INITN and DONE connections against the manufacturer's connection diagrams, together with the flash's voltage and command support. A successful JTAG load does not by itself prove the standalone flash boot path.
What fits in 1,008 kb of embedded memory?
As a capacity example, interpreting the documented 56 blocks as 56 × 18 × 1,024 bits gives 1,032,192 bits, or 129,024 raw bytes. Assume an uncompressed 640 × 480 image with one byte per pixel: one frame needs 307,200 bytes, so it exceeds that raw capacity even before buffering and control overhead. Line buffering, a smaller working region or external storage would need to be considered. This is an arithmetic planning example, not a measured video implementation; usable capacity also depends on memory width, depth and block allocation.
Replacement and sourcing review
A 45F or 85F part in BG381 is a migration candidate, not an automatically qualified substitute. Compare the official migration file ball by ball, regenerate a device-specific bitstream, rerun timing and check power and temperature. Switching to a UM variant to obtain SERDES changes the interface and supply review. A faster grade cannot replace that engineering work.
For a quotation, provide the exact order code, quantity, assembly schedule and required documentation. Ask for the offered lot, date code, packaging and applicable product-status information. A family data sheet is not live evidence of stock, lead time, lot compliance or future supply. Retain the manufacturer order code even if an internal catalog uses a shortened label.
Manufacturer documents
- ECP5 and ECP5-5G Family Data Sheet, FPGA-DS-02012-3.4, September 2025: Table 1.1, recommended operating conditions, configuration, pin summaries and commercial ordering tables.
- ECP5 and ECP5-5G Hardware Checklist, FPGA-TN-02038-2.1, September 2025: power, configuration connections and schematic checks.
- Device-specific ECP5U pinout; select the 381-ball package column.
- ECP5 documentation directory, including the caBGA381 migration file and current configuration and software resources.