EP2C35F484C8 FPGA: Technical Guide to Specs, Speed Grades, and Replacement

In the world of industrial electronics and embedded systems, the EP2C35F484C8 is a legendary component. It belongs to the Altera (now Intel) Cyclone II family, a series that redefined the FPGA market in the mid-2000s by offering high density at a low cost. While you won't choose this chip for a new AI server in 2025, it remains a critical lifeline for maintaining billions of dollars worth of existing infrastructure—from medical imaging devices to factory automation controllers.

If you are a technician looking to repair a legacy board, or a procurement manager trying to source an obsolete part, understanding the specific nuances of the "C8" speed grade is vital. This guide serves as your technical deep-dive into the EP2C35F484C8 datasheet, explaining its specifications, compatibility, and the software required to keep it running.

1.0 What is the EP2C35F484C8? (Datasheet Explained)

The EP2C35F484C8 is a specific model of Field-Programmable Gate Array (FPGA) from the Altera Cyclone II series. It is an SRAM-based device, meaning its logic configuration is volatile and must be loaded from an external memory chip every time the system powers up.

1.1 The Cyclone II Family: Cost-Effective 90nm Logic

Built on a 90nm process, the Cyclone II family was designed to compete with ASICs. It offered features that were previously only available in high-end FPGAs, such as: * **Embedded Multipliers:** For Digital Signal Processing (DSP). * **Phase-Locked Loops (PLLs):** For robust clock management. * **M4K Memory Blocks:** Dedicated on-chip RAM.

1.2 Decoding the Part Number: The "C8" Speed Grade

Every character in the part number **EP2C35F484C8** tells a story: * **EP2C:** Device Family (Cyclone II). * **35:** Device Density (**33,216 Logic Elements**). * **F:** Package Type (**FineLine BGA**). * **484:** Pin Count (**484 pins**). * **C:** Temperature Range (**Commercial**, 0°C to 85°C). * **8:** Speed Grade (**8**).

Critical Note: The -8 speed grade is the slowest grade available for this device (compared to -7 and -6). This has significant implications for replacement strategies, which we will discuss in Section 3.0.

1.3 Key Specifications Summary

Here are the hard numbers you need to know when validating this component:

Feature	Specification
Logic Elements (LEs)	33,216
Total RAM Bits	483,840 (105 M4K blocks)
Embedded Multipliers	35 (18x18)
PLLs	4
User I/O	322
Core Voltage	1.2V
Package	484-pin FBGA (23mm x 23mm)

2.0 EP2C35F484C8 Pinout and Package Details

The EP2C35F484C8 uses a 484-ball FineLine BGA (Ball Grid Array) package. This surface-mount package requires precise reflow soldering and cannot be easily serviced with a soldering iron.

2.1 FBGA-484 Package Overview

The pins are arranged in a 22x22 grid. * **Pitch:** 1.0 mm ball pitch. * **Mounting:** Surface Mount (SMT). * **Inspection:** Requires X-ray inspection to verify solder joint integrity after rework.

2.2 Critical Pins: VCCINT, VCCIO, and Configuration

When troubleshooting a board with this FPGA, check these pins first: * **VCCINT (Core Power):** Must be a stable **1.2V**. If this rail fails, the FPGA will not function. * **VCCIO (I/O Power):** The I/O banks are split into 8 groups. Each bank can operate at 1.5V, 1.8V, 2.5V, or 3.3V. Check the specific bank voltage for your application. * **nSTATUS & CONF_DONE:** These are status pins. If `nSTATUS` is low, the FPGA has detected an error. If `CONF_DONE` is low, the FPGA has not yet loaded its configuration.

3.0 Speed Grade Analysis: C8 vs. C7 vs. C6

This is the most common question we receive: "I can't find the C8, can I use a C7?"

3.1 What Does Speed Grade -8 Mean?

In FPGA terminology, the speed grade indicates the propagation delay of the internal logic. * **-6:** Fastest (Lowest delay). * **-7:** Medium. * **-8:** **Slowest** (Highest delay).

The EP2C35F484C8 is the economy version. It is tested to run at lower maximum frequencies than the C6 or C7.

3.2 Can I Replace a C8 with a C7?

**Yes.** Since the -8 is the slowest version, you can almost always replace it with a faster **-7** or **-6** version (e.g., EP2C35F484C7). The faster chip will meet all the timing constraints of the slower design. * **C8 -> C7:** **Safe Upgrade.** * **C7 -> C8:** **Risky.** The C8 might be too slow for a design that was compiled specifically for a C7.

4.0 Programming and Maintenance Guide

Working with legacy FPGAs requires legacy tools. You cannot use the latest software.

4.1 Required Legacy Software: Quartus II 13.0sp1

The Cyclone II family is **not supported** by the modern Intel Quartus Prime software. * **Required Version:** You must use **Altera Quartus II version 13.0 Service Pack 1** (or older). * **OS Support:** This software runs best on Windows 7. You may need a virtual machine to run it on Windows 10 or 11. * **Programmer:** Use a standard **USB-Blaster** to load the `.sof` file via JTAG, or to program the external EPCS flash device.

4.2 Obsolescence Strategy: MRO and Sourcing

The **EP2C35F484C8** is obsolete (EOL). Intel no longer manufactures it. * **For Repair:** You must source "New Old Stock" (NOS) or pulled parts from reliable distributors. * **For Redesign:** If you are redesigning the board, look at the **Cyclone 10 LP** or **Agilex** families, though these are *not* pin-compatible and require a completely new PCB layout.

In Conclusion

The EP2C35F484C8 FPGA is a testament to the longevity of industrial electronics. While it may be two decades old, its role in keeping critical systems operational is as important as ever. Whether you are troubleshooting a power rail, setting up a legacy Quartus environment, or hunting for stock, understanding the specific constraints of this "Speed Grade 8" device is key to success.

If you are struggling to find reliable stock of this obsolete component, you need a partner who specializes in legacy supply chains. Check our inventory for the EP2C35F484C8 at AichipLink, where we help engineers keep the world's infrastructure running.