Microchip Technology AT17F040A-30JU

Overview

AT17F040A-30JU from Microchip Technology (formerly Atmel) is a 4-Mbit in-system programmable FPGA configuration PROM in a 20-lead PLCC package, supporting serial download speeds up to 33 MHz, 5.0V-tolerant I/O pins, and cascading for multi-FPGA systems. It stores bitstream files for SRAM-based FPGAs including Altera Cyclone™, Stratix®, and APEX™ families.

For engineers reviewing the AT17F040A-30JU datasheet, AT17F040A-30JU pinout, AT17F040A-30JU application, or AT17F040A-30JU equivalent, key selection criteria include page-selectable 4-bitstream storage, 2-wire ISP capability, 3.3V operation with 5V-tolerant inputs, low-power standby (<3 mA), and compatibility with Master Serial mode FPGA configuration interfaces.

Technical Context

The AT17F040A-30JU implements a serial flash memory architecture optimized for FPGA configuration, using a 3.3V CMOS process with internal charge pumps for programming. Its control logic supports both FPGA-initiated serial readback and host-controlled 2-wire ISP via SER_EN activation.

It features four-page address partitioning (enabled by PAGE_EN and PAGESEL[1:0]), nCASC-driven daisy-chaining, and automatic power-on reset coordination via the READY signal. The device operates across –40°C to +85°C and integrates pull-up resistors on DATA, DCLK, and SER_EN pins per datasheet specifications.

Key Specifications

Pinout & Package

AT17F040A-30JU is packaged in a 20-lead Plastic J-Leaded Chip Carrier (PLCC), JEDEC MS-018 AA compliant, with 1.27 mm pitch and 9.78 mm × 9.78 mm body size. Pin 1 identifier is marked by a corner chamfer.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar FPGA configuration memory applications.

Compared with XC18V04PC44C, AT17F040A-30JU offers page-selectable reconfiguration and 2-wire ISP, while compared with AT17F040A-30CU, it provides through-hole PLCC socket compatibility and mechanical robustness for serviceable systems.

Availability

AT17F040A-30JU is available at Aetrix Electronics and suitable for industrial PLCs, wireless baseband systems, automated test equipment, and defense radar signal processors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for AT17F040A-30JU 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

Microchip Technology acquired Atmel in 2016 and maintains its FPGA configuration memory portfolio, emphasizing reliability, industrial qualification, and long-term supply assurance.

The AT17FxxxA series was designed specifically for seamless, low-risk integration into SRAM FPGA configuration chains-supporting Altera, Xilinx, and Atmel FPGA families with minimal glue logic and proven field performance.

FAQ

What is the primary function of the AT17F040A-30JU in an FPGA-based system?

The AT17F040A-30JU serves as a dedicated serial configuration PROM that stores and delivers bitstream data to SRAM-based FPGAs during power-up or reconfiguration. It operates in Master Serial mode, driving the FPGA's DIN and DCLK lines directly. Its 4-Mbit capacity supports full configuration of mid-range FPGAs, and its nCASC output enables daisy-chained multi-device setups. The AT17F040A-30JU eliminates the need for external controllers in standard FPGA boot sequences.

Can the AT17F040A-30JU be programmed in-system, and what interface does it use?

Yes, the AT17F040A-30JU supports in-system programming (ISP) via a 2-wire serial bus activated by pulling SER_EN low. It requires only VCC for programming-no external high-voltage supplies-as internal charge pumps generate necessary programming voltages. Compatible tools include the Atmel ATDH2225 ISP cable and third-party programmers supporting the AT17FxxxA protocol. The AT17F040A-30JU retains full functionality during ISP without disrupting system operation.

How does the PAGE_EN and PAGESEL[1:0] functionality work in the AT17F040A-30JU?

When PAGE_EN is high, the AT17F040A-30JU partitions its 4-Mbit address space (00000h–3FFFFh) into four equal 128 KB pages. PAGESEL[1:0] selects which page is active during serial download: 00 → 00000h–0FFFFh, 01 → 10000h–1FFFFh, 10 → 20000h–2FFFFh, 11 → 30000h–3FFFFh. This enables storage and rapid switching between up to four distinct FPGA configurations. When PAGE_EN is low, the device operates in linear mode across the full address range.

Is the AT17F040A-30JU compatible with both Altera and Xilinx FPGAs?

Yes, the AT17F040A-30JU is explicitly compatible with Altera FLEX®, Excalibur™, Stratix®, Cyclone™, and APEX™ devices, as well as Atmel AT40K and AT94K families. While not branded as Xilinx-compatible in the datasheet, its Master Serial interface, timing parameters (e.g., TCAC ≤30 ns), and pinout align with Xilinx XC18Vxx and XCFxx configuration PROM requirements. Many designs successfully use AT17F040A-30JU with Spartan and Virtex FPGAs when configured per Xilinx UG078 guidelines.

What is the role of the READY pin on the AT17F040A-30JU, and how should it be used?

READY is an open-collector output that drives low during the device's internal power-on reset cycle and releases (goes high-impedance) once initialization completes-typically within milliseconds. It provides FPGA or system controller visibility into PROM readiness. A 4.7 kΩ pull-up resistor is recommended if used. The AT17F040A-30JU's READY signal can synchronize FPGA configuration start or gate downstream logic, preventing race conditions during cold boot.