Microchip Technology ATF1504AS-15QC100

Overview

ATF1504AS-15QC100 from Microchip (formerly Atmel) is a high-density, electrically-erasable Complex Programmable Logic Device (CPLD) with 64 macrocells, 5 product terms per macrocell (expandable to 40), 7.5 ns pin-to-pin delay, 125 MHz registered operation, and 100-lead TQFP packaging. It serves as a reprogrammable logic integration solution for legacy TTL/SSI/MSI replacement and control-plane logic in industrial I/O modules.

For engineers reviewing the ATF1504AS-15QC100 datasheet, ATF1504AS-15QC100 pinout, ATF1504AS-15QC100 application, or ATF1504AS-15QC100 equivalent, this device delivers in-system programmability via JTAG, PCI-compliant I/O drive, flexible macrocell configuration (D/T/latch), and advanced power management including pin-controlled 1 mA standby mode - all critical for field-upgradable embedded control designs.

Technical Context

The ATF1504AS-15QC100 implements a global bus architecture feeding up to 40 signals into each logic block's switch matrix, enabling high routing density and successful pin-locked design iterations. Its 64 macrocells each generate buried feedback to the global bus and foldback terms to regional buses, supporting cascade logic chains with up to 40-product-term sum terms.

Each macrocell supports configurable flip-flops (D/T/JK/SR/latch) with clock sourced from global clocks (GCLK1–3) or individual product terms, asynchronous reset/preset, and output enable selectable per macrocell. ITD circuits on global clocks, inputs, and I/Os provide input transition detection for edge-sensitive control logic.

Key Specifications

Pinout & Package

ATF1504AS-15QC100 is packaged in a 100-lead Thin Quad Flat Package (TQFP) with 0.5 mm pitch, RoHS-compliant, and rated for industrial temperature range (–40°C to +85°C). Pin functions include 68 I/Os, 4 dedicated inputs (GCLK1–3, GCLR), 2 power-down pins (PD1/PD2), JTAG interface (TCK/TMS/TDI/TDO), and dual-supply rails (VCCIO/VCCINT/GND).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar CPLD applications.

Compared with XCR3064XL-10VQ100C and EPM3064ATC100-10, the ATF1504AS-15QC100 uniquely combines 5 V/3.3 V I/O compatibility, PCI-compliant drive, JTAG boundary-scan, and pin-keeper circuits - making it the only option among the three suitable for retrofitting legacy 5 V industrial controllers with field-upgrade capability.

Availability

ATF1504AS-15QC100 is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, legacy system glue logic replacement, and PCI bus interface controller applications requiring stable component supply and long-term lifecycle support.

Supply support for ATF1504AS-15QC100 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 continues to support its legacy PLD portfolio, including the ATF1504AS family, with full documentation, programming tools, and long-term availability commitments.

The ATF1504AS series was designed specifically for high-reliability, field-upgradable control logic in industrial automation, test equipment, and communications infrastructure - emphasizing in-system programmability, mixed-voltage I/O, and robust power management.

FAQ

What is the maximum operating frequency of the ATF1504AS-15QC100?

The ATF1504AS-15QC100 supports registered operation up to 125 MHz, as confirmed by its –15 speed grade rating and tCNT = 8 ns minimum global clock period. This frequency applies to synchronous logic paths using global clocks GCLK1–3; combinatorial paths achieve 7.5 ns pin-to-pin delay. The actual achievable system frequency depends on design complexity, routing, and timing closure achieved during fitting.

Does the ATF1504AS-15QC100 support both 3.3 V and 5.0 V I/O interfaces?

Yes, the ATF1504AS-15QC100 supports dual-voltage I/O operation: VCCIO may be set to either 3.0–3.6 V or 4.75–5.25 V, while VCCINT remains fixed at 5.0 V ±5%. This allows direct interfacing with both modern 3.3 V microcontrollers and legacy 5 V TTL/CMOS logic without level shifters - a key advantage for system upgrades.

How does the pin-keeper feature work on the ATF1504AS-15QC100?

The ATF1504AS-15QC100 includes programmable pin-keeper circuits on all inputs and I/Os. When enabled, these circuits retain the last driven logic state (high or low) after the driving source is removed, preventing floating inputs that cause shoot-through current and noise. This eliminates external pull-up resistors and associated DC power loss - especially valuable in high-pin-count industrial I/O designs.

Can the ATF1504AS-15QC100 be programmed in-system without removing it from the PCB?

Yes, the ATF1504AS-15QC100 is fully in-system programmable (ISP) via its 4-pin JTAG interface (TCK/TMS/TDI/TDO), compliant with IEEE Std. 1149.1-1990 and 1149.1a-1993. Programming can be performed using standard JTAG tools, Atmel-provided utilities, or third-party ATE systems - enabling field firmware updates and manufacturing programming without device removal.

What is the purpose of the PD1 and PD2 pins on the ATF1504AS-15QC100?

PD1 and PD2 are dedicated power-down control pins on the ATF1504AS-15QC100. When asserted high (with power-down mode enabled in the design file), either pin forces the device into a sub-10 mA standby state while latching all internal registers and maintaining valid output levels. These pins cannot serve as general-purpose logic inputs when power-down is active, but their macrocell resources remain usable for foldback/cascade logic.