EP20K400PI655-2X - APEX 20K 400K Gates FPGA, 655-Pin PQFP | Intel / Altera
MPN: EP20K400PI655-2X ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $185 | $185.00 |
| 10 | $165 | $1,650.00 |
| 100 | $140 | $14,000.00 |
| 500 | $120 | $60,000.00 |
| 1,000 | $105 | $105,000.00 |
EP20K400PI655-2X Overview
An FPGA (Field-Programmable Gate Array) is a type of integrated circuit that can be configured by the customer after manufacturing using a hardware description language. FPGAs sit in the broader taxonomy of programmable logic devices (PLDs) within digital semiconductors, positioned alongside CPLDs (Complex PLDs). They enable parallel processing, hardware-level reconfiguration, and rapid prototyping of digital logic without the cost and lead-time of an ASIC (Application-Specific Integrated Circuit).
Key features of the EP20K400PI655-2X include a maximum of 400,000 system gates, 16,640 logic elements, 166,400 RAM bits distributed across embedded system blocks (ESBs), and a maximum of 4 PLLs (phase-locked loops) for clock management. The device also features up to 488 user I/O pins, supports multiple I/O standards including LVTTL, LVCMOS, PCI, and GTL+, and offers 3.3V core voltage with 5V tolerant I/O. MultiVolt I/O allows interfacing with mixed-voltage subsystems without external level shifters.
The APEX 20K architecture uses a four-level hierarchical interconnect structure, providing fast and predictable routing across the device. The combination of LUTs, product-term logic, and dual-port RAM blocks in a single fabric makes the EP20K400 well suited for designs that merge data-path processing, glue logic, and memory functions. The "-2X" speed grade indicates a faster bin than the base "-2" grade, useful when timing closure is critical.
Typical applications include telecommunications line cards, industrial automation controllers, networking switches and routers, ASIC prototyping, DSP co-processing front-ends, and military/aerospace signal processing subsystems. The 655-pin PQFP package with perimeter-lead construction supports through-hole or socketed mounting, simplifying rework and field upgrades in long-lifecycle programs.
When designing with this device, plan for configuration ROM (EPC family) and a JTAG download chain. The PQFP-655 package is large (approximately 47.6 mm × 47.6 mm body), so allocate sufficient PCB area and consider thermal dissipation via the exposed thermal pad. The industrial temperature grade (-40C to +85C) is mandatory for outdoor and factory-floor deployments.
This page synthesizes distributor pricing, drop-in alternatives from the same APEX 20K family, and practical design notes not found in the original Altera datasheet, giving procurement and FPGA engineers a single source of truth for sourcing this mature APEX 20K device.
Drop-in alternatives for EP20K400PI655-2X — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with EP20K400PI655-2X (same form factor and footprint) — differing in Process Technology, Operating Temperature, Series, Package, Family.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
EP20K400BC652-2XV
✅ Drop-In✓ In Stock
$165 / Unit
View Datasheet →EP20K400BC652-1X
✅ Drop-In✓ In Stock
$140 / Unit
View Datasheet →EP20K400FC672-2
✅ Drop-In✓ In Stock
$171 / Unit
View Datasheet →EP20K400FI672-2X
✅ Drop-In✓ In Stock
$171 / Unit
View Datasheet →EP20K400GC655-2X
✅ Drop-In✓ In Stock
$175 / Unit
View Datasheet →EP20K400FI672-2
✅ Drop-In✓ In Stock
$92.4 / Unit
View Datasheet →EP20K400GC655-2
✅ Drop-In✓ In Stock
$80 / Unit
View Datasheet →EP20K400PI655-2X Maximum Ratings & Electrical Characteristics
| Family | APEX 20K |
| Device Series | EP20K400 |
| Speed Grade | -2X |
| Maximum Logic Elements | 16,640 |
| Maximum System Gates | 400,000 |
| Maximum RAM Bits | 166,400 |
| Embedded System Blocks (ESBs) | 104 |
| Maximum User I/O Pins | 488 |
| Maximum PLLs | 4 |
| Package | PQFP-655 (Power Quad Flat Pack) |
| Operating Temperature | -40C to +85C (Industrial) |
| Core Voltage | 3.3 V |
| I/O Standards | LVTTL, LVCMOS, PCI, GTL+ |
| Mounting Type | Surface Mount |
| Configuration Method | Serial / Parallel / JTAG |
| Process Technology | 0.18 um CMOS |
| Lifecycle Status | Obsolete (legacy Altera APEX 20K family) |
EP20K400PI655-2X pqfp-655 (power quad flat pack) Pin Configuration Guide
Pin configuration for EP20K400PI655-2X (pqfp-655 (power quad flat pack) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for EP20K400PI655-2X.
Refer to the datasheet for full pin configuration.
Typical Applications
EP20K400PI655-2X is suitable for 6 applications: Telecommunications Line Card Processing, ASIC Prototyping and HDL Verification, Industrial Automation and Process Control, Networking Switch and Router Line Cards, Military and Aerospace Signal Processing, DSP Co-Processing Front-End.
Telecommunications Line Card Processing
The EP20K400PI655-2X's 400,000 system gates and 488 user I/O pins make it well suited for telecommunications line card processing, where ATM, SONET, and DSL framers require parallel data-path logic alongside glue logic for network processors. The four on-chip PLLs enable multiple independent clock domains for TDM bus interfaces and Ethernet MACs, while the 166,400 bits of embedded RAM provide per-channel buffering without external SRAM. The PQFP-655 perimeter-lead package simplifies socketed field replacement in central-office equipment, and the industrial temperature grade ensures operation in -40C to +85C switch-room environments. Legacy telecom infrastructure still in service in 2026 includes this part in provisioning switches, cross-connects, and VoIP gateways.
Recommended
ASIC Prototyping and HDL Verification
The EP20K400PI655-2X has historically been a workhorse for ASIC prototyping and HDL verification, providing 400,000 system gates of configurable logic to emulate and validate pre-silicon ASIC RTL. Its 16,640 logic elements, 166,400 RAM bits, and 488 I/O pins allow engineers to map large ASIC designs that include processor cores, peripherals, and custom accelerators into a single FPGA. The PQFP-655 package with surface-mount construction supports rapid board spins, and JTAG-based configuration enables quick iteration cycles via download cables. Quartus II software (legacy versions 5.0 through 13.0) provides full synthesis and place-and-route support. In 2026, this part is preferred for ongoing ASIC regression testing in mature programs where validation infrastructure already targets APEX 20K.
Recommended
Industrial Automation and Process Control
The EP20K400PI655-2X fits industrial automation and process control applications requiring deterministic real-time logic for PLC backplanes, motor controllers, and SCADA interfaces. Its industrial operating temperature range (-40C to +85C) supports factory-floor and outdoor cabinets, while the 488 user I/O pins interface directly with discrete sensors, encoders, and actuators via LVTTL or 24V-isolated I/O. The four PLLs synthesize baud rates, PWM frequencies, and servo loop clocks from a single crystal reference. The 104 embedded system blocks (ESBs) implement dual-port RAM for inter-task message passing in real-time operating systems. Mature legacy programs in factory automation still rely on this part, taking advantage of the PQFP-655 socketed mount for easy field replacement.
Recommended
Networking Switch and Router Line Cards
The EP20K400PI655-2X powers legacy enterprise networking switches and router line cards where its combination of 16,640 logic elements, 488 I/O pins, and 166,400 RAM bits bridges network processors with PHY transceivers and TCAM lookup engines. The four PLLs drive GMII, RGMII, and SPI-4.2 interfaces at gigabit rates, while the 3.3V LVCMOS I/O standards interface directly with legacy PHY chips. MultiVolt I/O allows clean interfacing with 2.5V HSTL memories for packet buffers. The PQFP-655 package with surface-mount assembly is suitable for high-density line-card PCB layouts. Although Intel's newer Cyclone family is preferred for greenfield designs, the EP20K400PI655-2X remains in service in 2026 in installed-base networking gear from the late 1990s and early 2000s.
Recommended
Military and Aerospace Signal Processing
The EP20K400PI655-2X is suitable for military and aerospace signal processing subsystems where its industrial temperature range and high logic density enable radar, electronic warfare, and avionics DSP front-ends. The 400,000-gate capacity supports multi-channel FFT engines, adaptive beamformers, and crypto accelerators, while the four PLLs synchronize multiple A/D and D/A converters at deterministic phases. The PQFP-655 package, while not hermetically sealed, supports conformal coating and ruggedized enclosures typical of military platforms. Defense programs with long qualification cycles continue to specify this part due to its mature silicon and available documentation under ITAR/EAR. As of 2026, aftermarket channels remain the primary source for these long-life programs.
Recommended
DSP Co-Processing Front-End
The EP20K400PI655-2X functions as a DSP co-processing front-end in medical imaging, sonar, and scientific instrumentation systems, offloading filter, FFT, and beamforming operations from a host DSP or microprocessor. Its 16,640 logic elements implement systolic FIR and FFT pipelines at sample rates up to 250 MHz, while the 166,400 bits of embedded RAM provide data buffers and coefficient storage. The 488 user I/O pins connect directly to high-speed A/D converters via LVDS or parallel CMOS interfaces. The four PLLs synthesize the required sample clocks from a master reference, with deterministic latency thanks to the APEX 20K's structured interconnect. Legacy ultrasound and OCT imaging systems in production continue to use this FPGA, taking advantage of the well-characterized silicon and mature Quartus II design flow.
Recommended
Recommended Products Summary
Engineering reference data for EP20K400PI655-2X — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | EP20K400BC652-2X | EP20K400BC652-1X | EP20K400FC672-2 | EP20K400FI672-2X | EP20K400GC655-2X |
|---|---|---|---|---|---|---|
| Brand | Intel | Intel | Intel | Intel | Intel | Intel |
| Package | PQFP-655 | BGA-652 | BGA-652 | BGA-672 | BGA-672 | BGA-655 |
| Maximum System Gates | 400,000 | 400,000 | 400,000 | 400,000 | 400,000 | 400,000 |
| Maximum Logic Elements | 16,640 | 16,640 | 16,640 | 16,640 | 16,640 | 16,640 |
| Maximum RAM Bits | 166,400 | 166,400 | 166,400 | 166,400 | 166,400 | 166,400 |
| Maximum User I/O | 488 | 488 | 488 | 488 | 488 | 488 |
| Speed Grade | -2X | -2X | -1X | -2 | -2X | -2X |
| Core Voltage | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- PQFP-655 package for socketed field replacement (vs EP20K400BC652-2X (BGA-652))
- -2X speed grade for tighter timing margins (vs EP20K400GC655-2 (BGA-655, -2 base speed grade))
- Industrial temperature grade (-40C to +85C) (vs EP20K400BC652-1X (Commercial 0C to +70C))
Design Notes
The EP20K400PI655-2X requires a stable 3.3V core supply with a maximum tolerance of +/- 5%. Use a low-noise LDO (e.g., LT1764 or TPS7A4701) rather than a switching regulator to power VCCINT, because the APEX 20K's analog PLLs are sensitive to supply ripple. Decouple each VCCINT pin with a 0.1 uF ceramic capacitor placed as close to the pin as possible, plus a bulk 10 uF tantalum or polymer cap near the package. The I/O banks (VCCIO) may be powered independently at 1.5V, 1.8V, 2.5V, or 3.3V via MultiVolt I/O to interface with mixed-voltage subsystems. PCI compliance requires VCCIO = 3.3V on the bank driving PCI bus pins.
The PQFP-655 package has a thermal resistance (theta_JA) of approximately 15 C/W in still air, requiring thermal management if power dissipation exceeds 3W. Estimated: at 100% logic utilization with typical 50% toggle rate, the EP20K400 dissipates approximately 4-6W, which would yield a 60-90C junction-temperature rise above ambient in still air. To stay within the -40C to +85C industrial range at +55C ambient, attach a heatsink with thermal interface material, or use forced-air cooling at 1-2 m/s. The exposed thermal pad (if present in the chosen PQFP-655 variant) must be soldered to a copper pour with thermal vias for additional dissipation.
Three common pitfalls plague designers porting the EP20K400PI655-2X. First, MSEL[2:0] pins must be configured correctly for the chosen configuration mode (PS, PPA, PPS, JTAG) - leaving them floating or wrong causes configuration failure. Second, the nSTATUS and CONF_DONE pins require external 10 kohm pull-up resistors to VCCIO; if omitted, the FPGA reports configuration errors at power-up. Third, the JTAG chain (TCK, TMS, TDI, TDO, TRST) must follow the IEEE 1149.1 / 1532 specification with TRST pulled low or properly toggled per Altera's BSDL file - violation prevents in-system programming. Always include the JTAG header on production boards to enable field updates and firmware recovery.
The PQFP-655 package has 0.5 mm pitch leads on all four sides, requiring precise PCB layout. Recommended: use a 4-layer PCB with continuous ground plane beneath the FPGA to provide a low-impedance return path and shield the high-speed I/O signals. Route clock traces (CLK[3:0], INCLK) with controlled impedance (50 ohm microstrip) and length matching within 100 ps to all synchronous logic blocks. Place configuration memory (EPC2, EPC4, EPC8, EPC16) within 50 mm of the DATA, DCLK, and nCONFIG pins to minimize signal integrity issues. Add 0.1 uF bypass caps on every VCCIO and VCCINT pin, and bulk decoupling (10-47 uF) within 25 mm of the package.
Compliance Information
The EP20K400PI655-2X is a legacy Altera APEX 20K part. Original Altera datasheets did not include RoHS compliance declarations for the PQFP-655 package variants produced before the 2006 RoHS transition. Pb-free options exist under different ordering codes. Compliance status should be verified per specific date code and lot when sourcing from aftermarket distributors. AEC-Q100 not applicable - this is an FPGA, not an automotive-grade discrete IC.
