Microchip Technology ATF1502ASL-25AU44

Overview

ATF1502ASL-25AU44 from Microchip Technology (formerly Atmel) is a high-density, electrically-erasable Complex Programmable Logic Device (CPLD) with 32 macrocells, 5 base product terms per macrocell expandable to 40, 44-pin TQFP package, 7.5 ns maximum pin-to-pin delay, and support for registered operation up to 125 MHz. It serves as a logic integration solution in industrial control I/O expansion modules requiring deterministic timing and in-system reprogrammability.

For engineers reviewing the ATF1502ASL-25AU44 datasheet, ATF1502ASL-25AU44 pinout, ATF1502ASL-25AU44 application, or ATF1502ASL-25AU44 equivalent, key selection considerations include its 10 μA standby current in "L" version, JTAG-compliant ISP capability, PCI-compliant output drive, programmable slew rate, and Input Transition Detection (ITD) on global clocks and I/Os.

Technical Context

The ATF1502ASL-25AU44 implements a two-block CPLD architecture with a shared global bus feeding 40 signals into each logic block's switch matrix, enabling flexible routing and pin-locked design iterations. Its macrocell supports D/T latch configurable flip-flops, combinatorial outputs with registered feedback, and buried foldback logic for regional cascading.

It integrates IEEE 1149.1-compliant JTAG boundary-scan testing, In-System Programmability via TDI/TDO/TMS/TCK pins, and advanced power management including automatic 10 μA standby, pin-controlled 1 mA power-down mode, and per-macrocell reduced-power bit. The "L" suffix confirms low-power EEPROM technology with 20-year data retention and 10,000 program/erase cycles.

Key Specifications

Pinout & Package

ATF1502ASL-25AU44 is housed in a 44-lead Thin Quad Flat Package (TQFP), 10 mm × 10 mm, 0.8 mm pitch, RoHS-compliant and green (Pb/halide-free). Pin functions are defined per Figure 1-1 of the datasheet, with dedicated global clock (GCLK1–GCLK3), global clear (GCLR), output enable (OE1, OE2), power-down (PD1, PD2), and JTAG (TDI, TDO, TMS, TCK) pins alongside 32 bi-directional I/Os.

Key Features

Applications

Equivalent & Alternatives

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

Compared with XCR3064XL-10VQ44C, ATF1502ASL-25AU44 offers superior low-power operation and hardware event detection, while ATF1504ASL-25AU44 provides seamless scalability within the same family-making both alternatives viable depending on whether density or ultra-low-power determinism is prioritized.

Availability

ATF1502ASL-25AU44 is available at Aetrix Electronics and suitable for industrial control systems, legacy bus interface bridges, and automated test equipment requiring stable component supply, long-lifecycle support, and verified RoHS compliance.

Supply support for ATF1502ASL-25AU44 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 manufacture, support, and qualify legacy Atmel PLD products including the ATF1502AS(L) series for industrial and aerospace applications.

The ATF1502AS(L) product line was designed to replace TTL/MSI logic and older PLDs in cost-sensitive, high-reliability embedded systems where in-system reprogrammability, low power, and deterministic timing are essential.

FAQ

What is the maximum operating frequency of the ATF1502ASL-25AU44?

The ATF1502ASL-25AU44 supports registered operation up to 125 MHz, as confirmed by its –25 speed grade designation and AC characteristics table (fCNT = 125 MHz). This applies to global clocked logic paths; combinatorial paths are limited by the 7.5 ns pin-to-pin delay. The actual achievable frequency depends on design utilization, routing, and macrocell configuration - the ATF1502ASL-25AU44 fitter software reports timing closure against this specification.

Does the ATF1502ASL-25AU44 support in-system programming (ISP)?

Yes, the ATF1502ASL-25AU44 fully supports IEEE 1149.1-compliant In-System Programming via its dedicated 4-pin JTAG interface (TDI, TDO, TMS, TCK). ISP allows full configuration, erase, and reprogramming while soldered on the PCB - eliminating socketing requirements and enabling field firmware updates. The ATF1502ASL-25AU44 ships erased and ready for ISP out of the box.

What power-saving features does the ATF1502ASL-25AU44 offer beyond standard standby mode?

Beyond its 10 μA automatic standby, the ATF1502ASL-25AU44 provides three additional power-saving mechanisms: (1) pin-controlled power-down mode (<5 mA), (2) per-macrocell reduced-power bit to disable unused logic, and (3) Input Transition Detection (ITD) that enables wake-on-event without continuous polling. These features are hardware-implemented and require no external components - all are configurable in the ATF1502ASL-25AU44 design file.

Can the ATF1502ASL-25AU44 be used in PCI-compliant designs?

Yes, the ATF1502ASL-25AU44 meets PCI Local Bus Specification DC requirements, including VOH ≥2.4 V at –2 mA and VOL ≤0.55 V at 3–6 mA. Its programmable high-drive outputs deliver PCI-compliant signaling without external buffers, and its low output-to-output skew ensures timing integrity across multi-bit data buses - making the ATF1502ASL-25AU44 suitable for add-in cards and host-bridge logic.

How many global clock inputs does the ATF1502ASL-25AU44 have, and what special functionality do they support?

The ATF1502ASL-25AU44 has three dedicated global clock inputs: GCLK1, GCLK2, and GCLK3. Each supports Input Transition Detection (ITD), allowing hardware-level edge detection to trigger wake-up from standby or initiate state transitions without CPU intervention. These clocks feed directly into the global bus and can be individually assigned to macrocells - the ATF1502ASL-25AU44 architecture permits mixed-clock-domain logic within a single device.