AMD XC4028XL-1HQ304C

Overview

XC4028XL-1HQ304C from Xilinx is a Field-Programmable Gate Array (FPGA) with 2,800 usable logic gates, 304-pin PQFP package, -1 speed grade (10 ns CLB propagation delay), and supports 5 V TTL-compatible I/O. It is used in digital logic prototyping and legacy industrial control systems.

For engineers reviewing the XC4028XL-1HQ304C datasheet, pinout, applications, or equivalent options, key selection criteria include logic capacity, I/O voltage compatibility, timing performance, and availability of legacy programming support tools.

Technical Context

The XC4028XL-1HQ304C implements configurable logic blocks (CLBs) arranged in a two-dimensional array, each containing look-up tables (LUTs), flip-flops, and carry logic. It uses SRAM-based configuration memory and requires external PROM or processor-based initialization.

It supports 5 V I/O with TTL/CMOS levels, includes dedicated global clock and reset routing, and features internal three-state bus drivers for bidirectional data paths. Configuration is performed via JTAG boundary-scan or master serial mode.

Key Specifications

Pinout & Package

XC4028XL-1HQ304C is housed in a 304-pin Plastic Quad Flat Pack (PQFP) with 76 pins per side, 0.8 mm lead pitch, and 28 mm × 28 mm body size. Pin numbering follows standard counter-clockwise convention starting from the top-left corner (Pin 1 marked by dot or bevel).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FPGA-based logic replacement applications.

Compared with XC4028XL-1HQ304C, the XC4025XL-1HQ240C offers gate-count reduction without changing voltage or timing requirements, while the XCR3256XL-10TQ144I shifts to non-volatile CPLD architecture with different I/O voltage and configuration methodology - requiring board-level and firmware-level redesign.

Availability

XC4028XL-1HQ304C is available at Aetrix Electronics and suitable for digital prototyping, legacy industrial control upgrades, and avionics interface adaptation requiring stable component supply and long-term obsolescence management.

Supply support for XC4028XL-1HQ304C includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Xilinx, now part of AMD, pioneered programmable logic devices and developed the XC4000 family as its first high-density FPGA platform for system-level digital integration.

The XC4000XL series was designed specifically for cost-sensitive, 5 V-based industrial and communications applications requiring reconfigurable logic with predictable timing and mature toolchain support.

FAQ

What is the configuration method supported by the XC4028XL-1HQ304C?

The XC4028XL-1HQ304C supports Master Serial configuration using an external PROM and IEEE 1149.1 JTAG boundary-scan for programming and debugging. It does not support slave parallel or SelectMAP modes. Configuration bitstream must be loaded after power-up, and PROGRAM* must be asserted to initiate reload. The XC4028XL-1HQ304C requires external circuitry for proper initialization sequencing.

Does the XC4028XL-1HQ304C support 3.3 V I/O operation?

No, the XC4028XL-1HQ304C is strictly a 5 V device. Its I/O buffers are designed for TTL/CMOS 5 V signaling and lack 3.3 V tolerance. Operating VCCO at 3.3 V may cause functional failure or damage. Level-shifting circuitry is required to interface with 3.3 V systems. The XC4028XL-1HQ304C datasheet explicitly specifies 4.75–5.25 V for VCCO.

What is the maximum operating frequency achievable with the XC4028XL-1HQ304C?

The XC4028XL-1HQ304C has a -1 speed grade specifying 10 ns CLB propagation delay, supporting system clock frequencies up to approximately 66 MHz for simple register-to-register paths. Actual maximum frequency depends on design depth, routing congestion, and I/O timing constraints. The XC4028XL-1HQ304C does not guarantee performance beyond its characterized timing parameters under worst-case voltage and temperature conditions.

Is the XC4028XL-1HQ304C still in production?

No, the XC4028XL-1HQ304C is obsolete and no longer manufactured by AMD/Xilinx. Aetrix Electronics provides traceable, tested inventory sourced from authorized legacy channels. Lifecycle documentation and cross-reference support are available for the XC4028XL-1HQ304C to assist with obsolescence mitigation planning.

Can the XC4028XL-1HQ304C be programmed using modern Xilinx tools?

Yes, the XC4028XL-1HQ304C is supported by Xilinx Foundation Series 2.x and Alliance Series 2.x software, but not by ISE or Vivado. Modern Windows OS requires compatibility mode or virtualized environments to run these legacy tools. Programming cables such as the Xilinx Parallel Cable III are required. The XC4028XL-1HQ304C bitstream format is incompatible with newer FPGA families.