Microchip Technology ATF1504AS-7AC44

Overview

ATF1504AS-7AC44 from Atmel (now Microchip) 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 44-pin 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 and embedded system glue logic.

For engineers reviewing the ATF1504AS-7AC44 datasheet, ATF1504AS-7AC44 pinout, ATF1504AS-7AC44 application, or ATF1504AS-7AC44 equivalent, this page delivers verified timing specs, JTAG ISP capability, PCI-compliant I/O drive, power-down mode configuration, and macrocell-level power management features confirmed for the -7 speed grade in 44-pin TQFP.

Technical Context

The ATF1504AS-7AC44 implements a hierarchical CPLD architecture with four logic blocks, each fed by a global bus carrying all 68 possible inputs (including 64 buried macrocell feedbacks) and regional foldback buses enabling up to 16-term sum-of-products within a block. Its switch matrix selects up to 40 signals per logic block from the global bus.

Each macrocell supports configurable D/T/latch flip-flops clocked by global clocks (GCLK1–3) or product-term-derived clocks, with asynchronous clear (GCLR), individual output enable (OE1/OE2), programmable slew rate, open-collector option, and pin-keeper circuits - all independently assignable per macrocell via fuse-bit programming.

Key Specifications

Pinout & Package

ATF1504AS-7AC44 is packaged in a 44-lead Thin Quad Flat Package (TQFP) with 0.8 mm lead pitch, JEDEC MO-153 compliant, body size 10 × 10 mm. Pin 1 is marked by a dot or beveled corner; top view orientation follows standard TQFP labeling.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ATF1504ASL-7AC44, the ATF1504AS-7AC44 omits automatic µA standby but retains identical speed, I/O count, and PCI compliance; versus XC9536-7PC44, it delivers 78% more macrocells, triple global clocks, and native PCI drive - making it suitable for higher-complexity, standards-compliant industrial control applications.

Availability

ATF1504AS-7AC44 is available at Aetrix Electronics and suitable for industrial control logic, legacy system glue logic, PCI interface adapters, and embedded boot sequencing requiring stable component supply across extended lifecycle programs.

Supply support for ATF1504AS-7AC44 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 (acquired by Microchip Technology in 2016) is a semiconductor manufacturer specializing in microcontrollers, nonvolatile memory, and programmable logic devices with strong heritage in EEPROM-based PLDs.

The ATF1504AS family was designed for high-reliability, in-system reprogrammable logic integration in industrial, telecom, and embedded systems requiring deterministic timing, PCI compliance, and long-term data retention.

FAQ

What is the maximum operating frequency of the ATF1504AS-7AC44?

The ATF1504AS-7AC44 supports registered operation up to 125 MHz and combinatorial paths with 7.5 ns maximum pin-to-pin delay. Its maximum internal global clock frequency is 125 MHz at the -7 speed grade, confirmed in the AC Characteristics table under fCNT and fACNT parameters. This applies to both global clock domains (GCLK1–3) and array clocks when configured per the device's timing model.

Does the ATF1504AS-7AC44 support JTAG boundary-scan testing?

Yes, the ATF1504AS-7AC44 fully supports IEEE Std. 1149.1-1990 and 1149.1a-1993 boundary-scan testing via its dedicated TDI, TDO, TMS, and TCK pins. Each I/O and input pin includes a boundary-scan cell (BSC), and the device provides SAMPLE/PRELOAD, EXTEST, BYPASS, IDCODE, and HIGHZ JTAG modes - all documented in its official BSDL file.

Can the ATF1504AS-7AC44 operate with both 3.3 V and 5.0 V I/O voltages?

Yes, the ATF1504AS-7AC44 supports dual-voltage I/O operation: VCCIO can be set to either 5.0 V ±5% (commercial) or 3.3 V (3.0–3.6 V range). The device maintains full functionality-including PCI compliance, slew rate control, and JTAG ISP-at both voltage levels, with DC and AC characteristics specified separately for each condition in the datasheet.

What is the purpose of the PD1 and PD2 pins on the ATF1504AS-7AC44?

The PD1 and PD2 pins on the ATF1504AS-7AC44 provide optional pin-controlled power-down functionality. When enabled in the design file, asserting either PD1 or PD2 high reduces supply current to below 10 mA while latching all internal states and outputs. These pins cannot serve as logic I/O when power-down is active, though their macrocell resources remain usable for foldback and cascade logic.

How does the ATF1504AS-7AC44 handle power-up reset and initialization?

The ATF1504AS-7AC44 includes a built-in power-up reset circuit that initializes all registers when VCC crosses the VRST threshold. Users may select "Small" or "Large" hysteresis during fitting; the Large option reduces ICC by several hundred µA but requires VCC to fall below 2.0 V before re-powering. Reset behavior is asynchronous and requires monotonic VCC rise and proper setup/hold timing on inputs post-reset.