Field Programmable Gate Array[2]

Updated: 2026-09-09

Overview

The EP20K400BI652-2 is a member of Altera's (now Intel) APEX 20K FPGA family, a series of high-density programmable logic devices. As a Field Programmable Gate Array, it offers designers the flexibility to implement custom digital circuits through programmable logic blocks and interconnects. This particular model was widely used in industrial and telecom applications during its production period. The '400' in the part number indicates the device's logic capacity (approximately 400,000 system gates), while the '652' suffix refers to its 652-pin ball grid array (BGA) package. These FPGAs were known for their combination of high performance and flexibility, making them suitable for complex digital systems that required frequent updates or customization.

Structure and Working Principle

The EP20K400BI652-2 features a hierarchical architecture with logic elements (LEs) organized into logic array blocks (LABs). Each LE contains a 4-input lookup table (LUT) and a programmable flip-flop, allowing implementation of complex combinational and sequential logic. The device includes embedded memory blocks (ESBs) that can be configured as RAM or ROM, and supports various I/O standards through its programmable I/O blocks. FPGAs like the EP20K400BI652-2 operate by configuring SRAM-based cells that control the interconnection of logic elements and the functionality of each block. This configuration is typically loaded from an external memory device during power-up, allowing the same physical chip to implement completely different circuit designs by simply changing the configuration bitstream.

Key Features

The EP20K400BI652-2 offers several notable features that made it popular for complex digital designs. It provides approximately 400,000 system gates, 16,640 logic elements, and 442 user I/O pins in the 652-pin package. The device includes 160 embedded system blocks (ESBs) that can be configured as memory (up to 212K bits) or logic functions. Performance-wise, it supports typical system speeds up to 250 MHz, with embedded PLLs for clock management. The device operates at core voltages of 2.5V with 3.3V or 2.5V I/O options, offering flexibility in system design. Its multi-voltage capability allows interfacing with various logic families while maintaining power efficiency.

Application Areas

The EP20K400BI652-2 found widespread use in telecommunications infrastructure, particularly in digital signal processing applications such as base stations and network switches. Its high gate count and programmable nature made it ideal for protocol conversion, traffic management, and signal conditioning tasks. Industrial applications included factory automation systems, medical imaging equipment, and test/measurement instruments. The FPGA's ability to implement parallel processing architectures was particularly valuable in real-time control systems. Additionally, it was used in military/aerospace applications where field-upgradable hardware was essential, though newer devices have largely replaced it in these sectors.

Maintenance and Precautions

When working with the EP20K400BI652-2, proper handling procedures are critical due to its BGA package and sensitivity to electrostatic discharge (ESD). Technicians should always use grounded wrist straps and work on ESD-safe surfaces. The device requires careful attention to power supply sequencing during startup to prevent latch-up conditions. For system maintenance, it's important to ensure the configuration memory is properly programmed and that the power supply voltages remain within specifications. In deployed systems, monitoring operating temperatures is recommended as excessive heat can affect reliability. Because this is an older FPGA model, availability of programming tools and support documentation may be limited compared to current-generation devices.

B2B Procurement Guide

When procuring the EP20K400BI652-2 in B2B transactions, buyers should verify the authenticity of components due to the risk of counterfeit parts in the obsolete semiconductor market. It's advisable to work with authorized distributors or reputable suppliers with established quality control processes. Lead times may vary significantly as this is a discontinued part, with pricing typically higher than original manufacturer prices due to limited availability. Buyers should carefully consider their required quantities, as small orders may be difficult to fulfill while large orders might require verification of proper storage conditions for any remaining inventory. Alternative solutions using newer FPGA families should be evaluated for long-term projects.