Microchip Technology AT17F040-30JU

Overview

AT17F040-30JU from Microchip Technology (formerly Atmel) is a 4-Mbit FPGA configuration PROM in 20-lead PLCC package, supporting serial master-mode download at up to 33 MHz, with 5.0V-tolerant I/O pins, 3.3V operation, and cascading capability via CEO/CE daisy-chain interface for multi-FPGA systems.

For engineers reviewing the AT17F040-30JU datasheet, AT17F040-30JU pinout, AT17F040-30JU application, or AT17F040-30JU equivalent, this device serves as a nonvolatile configuration memory for Xilinx XC3000/XC4000/Spartan/Virtex, Altera FLEX/APEX, Lucent ORCA, and Atmel AT40K/AT94K FPGAs - requiring precise timing alignment, page-select control, and low-power standby behavior.

Technical Context

The AT17F040-30JU implements a serial flash-based configuration architecture with internal address/bit counters synchronized to FPGA CCLK, enabling direct master-serial boot without external controller. It supports both continuous read mode and four-page partitioned download using PAGE_EN and PAGESEL[1:0] inputs.

Its 2-wire ISP programming mode (enabled by SER_EN = Low) operates independently of CE/RESET/OE logic and uses A2 for device selection. The CEO output provides automatic daisy-chain handoff by asserting low upon end-of-data, triggering the next device's CE input.

Key Specifications

Pinout & Package

AT17F040-30JU is packaged in a 20-lead Plastic J-Leaded Chip Carrier (PLCC), JEDEC MS-018 AA compliant, with 1.27 mm pitch, 9.78 mm × 9.78 mm body, and 4.19–4.57 mm height. 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 XC18V04 and AT17F040-30CU, the AT17F040-30JU uniquely combines 5V-tolerant I/O, hardware page-select, and CEO-driven daisy-chain in a through-hole PLCC package - making it optimal for industrial upgrades, test fixtures requiring socket access, and mixed-voltage FPGA systems needing robust configuration handoff.

Availability

AT17F040-30JU is available at Aetrix Electronics and suitable for industrial PLCs, FPGA-based test equipment, communications prototyping platforms, and avionics signal processors requiring stable component supply across extended product lifecycles.

Supply support for AT17F040-30JU 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 full support for the AT17F family. The company specializes in microcontrollers, analog, FPGA configuration, and secure authentication ICs for industrial, automotive, and aerospace markets.

The AT17F series was designed specifically as cost-effective, pin-compatible configuration PROMs for SRAM-based FPGAs - emphasizing simplicity, cascading scalability, and in-system reprogrammability without external controllers.

FAQ

What is the maximum clock frequency supported by AT17F040-30JU during FPGA configuration?

The AT17F040-30JU supports a maximum input clock frequency of 33 MHz when SER_EN is high (normal configuration mode). This allows fast bitstream loading for Xilinx Spartan and Virtex families. The 10 MHz limit applies only during 2-wire ISP programming (SER_EN = Low), per AC Characteristics Table 9-3.

Does AT17F040-30JU support daisy-chaining with other configuration PROMs?

Yes, AT17F040-30JU supports hardware daisy-chaining via its CEO output and CE input. When the device finishes transmitting its bitstream, CEO goes low to enable the CE input of the next AT17F-series device in the chain. This eliminates FPGA GPIO usage and ensures deterministic inter-device handoff timing.

Can AT17F040-30JU store multiple FPGA bitstreams?

Yes, AT17F040-30JU supports storing up to four independent 1-Mbit bitstreams using its page-select feature. With PAGE_EN high and PAGESEL[1:0] set to 00, 01, 10, or 11, the device accesses distinct 1-Mbit address partitions (00000h–0FFFFh, etc.), enabling runtime FPGA reconfiguration without external memory.

Is AT17F040-30JU compatible with Xilinx Virtex FPGAs?

Yes, AT17F040-30JU is explicitly listed as compatible with Xilinx Virtex, Spartan, XC3000, and XC4000 FPGAs in the official datasheet. Its timing parameters (e.g., TCAC = 30 ns, TOE = 55 ns) meet Virtex-4/E/5 master-serial interface requirements when operated within specified VCC and temperature ranges.

What is the purpose of the READY pin on AT17F040-30JU?

The READY pin on AT17F040-30JU is an open-collector output that signals power-on reset completion. It is driven low during internal POR and released (tri-stated) once initialization finishes. A 4.7 kΩ pull-up is recommended if used to synchronize FPGA startup or monitor configuration readiness.