Microchip Technology ATF2500CL-20JC

Overview

ATF2500CL-20JC from Atmel is a high-density, electrically-erasable CPLD with 24 macrocells, 48 flip-flops (D- or T-type configurable), and a fully connected logic array delivering 416 product terms. It features 15 ns pin-to-pin delay at 5V, individual asynchronous reset per macrocell, and OE control per output - used in legacy industrial control logic replacement and FPGA migration support.

For engineers reviewing the ATF2500CL-20JC datasheet, ATF2500CL-20JC pinout, ATF2500CL-20JC application, or ATF2500CL-20JC equivalent, key selection criteria include its 20 ns tPD timing grade, PLCC-44 green package (Pb/Halide-free), 0°C to 70°C commercial temperature range, and backward compatibility with ATV2500B/BQ/ATV2500H software toolchains.

Technical Context

The ATF2500CL-20JC implements a single universal logic array where all 38 I/O pins and 48 register feedback paths feed directly into every macrocell. Its architecture supports combinable sum terms (up to 12 product terms per sum term) and independent clocking per flip-flop via dedicated product terms or direct input pins.

Each of the 24 macrocells provides two registers (Q1/Q2), programmable pin-keeper circuits, synchronous preset distribution (8 terms across 4–8 macrocell groups), and selectable registered/combinatorial output modes - enabling mixed-clock state machines, counters, and bus interface logic without external glue logic.

Key Specifications

Pinout & Package

ATF2500CL-20JC uses a 44-lead Plastic Leaded Chip Carrier (PLCC-44, package code 44J) with standard JEDEC MS-018 AC footprint (17.5 mm × 17.5 mm body, 1.27 mm lead pitch). Pin 1 identifier is a corner chamfer; seating plane tolerance is 0.102 mm max coplanarity.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ATF2500C-20JC, the ATF2500CL-20JC adds RoHS compliance without timing or logic trade-offs; versus ATV2500H, it delivers 25% more gates, faster timing, and security - making it the sole choice for new industrial control and test equipment designs requiring long-term component availability and regulatory adherence.

Availability

ATF2500CL-20JC is available at Aetrix Electronics and suitable for industrial PLC upgrades, legacy system re-engineering, and automated test equipment requiring stable component supply with 10-year data retention and military-grade ESD protection.

Supply support for ATF2500CL-20JC 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

Atmel Corporation (now part of Microchip Technology) is a fabless semiconductor company specializing in nonvolatile memory, microcontrollers, and programmable logic devices for industrial and automotive markets.

The ATF2500C family was designed to replace obsolete bipolar PALs and provide high-density, reprogrammable logic for space-constrained industrial control and instrumentation applications - emphasizing field-upgradability, security, and long-term manufacturability.

FAQ

What is the operating voltage range for ATF2500CL-20JC?

The ATF2500CL-20JC operates strictly at 5V ±5% (4.75V to 5.25V). It does not support 3.3V or mixed-voltage operation. Deviations outside this range risk incorrect register reset behavior, increased ICC standby current, or permanent damage per Absolute Maximum Ratings. The ATF2500CL-20JC requires clean, well-decoupled 5V power with ≤100 mV ripple to meet tPR (600–1000 ns) power-up reset timing.

Is ATF2500CL-20JC pin-compatible with ATV2500H?

Yes, ATF2500CL-20JC is pin-compatible with ATV2500H in PLCC-44 packages, including identical pin 4 and pin 26 GND recommendations. However, ATF2500CL-20JC supports additional features (T-type registers, pin-keeper, security fuse) that require recompilation of source design files. For drop-in replacement, use Atmel WinCUPL's V2500 cross-programming mode to generate compatible JEDEC files.

How does the security fuse affect ATF2500CL-20JC functionality?

Once programmed, the ATF2500CL-20JC security fuse permanently disables fuse pattern readback, preload functionality, and Q2 observability mode. It does not alter logic behavior or timing - the device operates identically post-security-enable. Programming must occur last in the programming sequence, as its effect is immediate and irreversible. The ATF2500CL-20JC security fuse is distinct from configuration fuses and does not impact user-row data access.

What is the purpose of the pin-keeper feature in ATF2500CL-20JC?

The pin-keeper in ATF2500CL-20JC is a weak active latch on each I/O pin that holds the last driven logic state when the pin is floating - preventing undefined inputs during bus arbitration or power sequencing. It is disabled by default and enabled only when selecting "V2500CPPKLCC" device type in Atmel WinCUPL. The ATF2500CL-20JC pin-keeper draws negligible current (<10 µA) and is overridden cleanly by TTL-compatible drivers.

Does ATF2500CL-20JC support both product-term and pin-based clocking?

Yes, ATF2500CL-20JC supports both clocking methods per flip-flop: dedicated product-term clocks (enabling multi-clock-domain designs) and direct CLK/IN pin clocking (for highest-speed synchronous operation). Each of the 48 registers has independent clock source selection via configuration bits. This dual-clock capability allows mixing 40 MHz pin-clocked counters with slower product-term-clocked state machines in the same ATF2500CL-20JC device.