AT89LS8252-12AC Equivalent & Substitute Parts

Part Overview

The AT89LS8252-12AC is an 8051-based 8-bit microcontroller manufactured by Microchip Technology, featuring 8KB FLASH program memory and operating at 12MHz. This device is classified as obsolete, making substitute components necessary for new designs and production continuity. The part is available in 44-TQFP surface mount packaging with 32 I/O pins and operates across a 2.7V to 6V supply voltage range.

Substiute Parts

AT89LS8252-12AC

Microchip TechnologyIn Stock: 14480AT89LS8252-12AC Datasheet

Current PartRFQ

AT89S8253-24AU

Microchip TechnologyIn Stock: 3045AT89S8253-24AU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89LS8252-12AC is determined by the following critical parameters:

Core Architecture Compatibility: Both the main part and substitute must utilize the 8051 core processor to ensure firmware compatibility and instruction set alignment.

Package Compatibility: The 44-TQFP (10x10) surface mount package is mandatory for PCB layout compatibility without redesign.

I/O Pin Count: 32 I/O pins must be maintained to preserve circuit interface requirements.

Memory Architecture: EEPROM (2K x 8) and RAM (256 x 8) configurations must match or exceed the original specification.

Voltage Supply Range: The substitute must operate within or encompass the 2.7V to 6V supply voltage window.

Connectivity Interfaces: SPI and UART/USART interfaces must be present for peripheral communication compatibility.

Peripheral Features: Power-On Reset (POR) and Watchdog Timer (WDT) functionality must be retained.

The AT89S8253-24AU qualifies as a direct substitute based on these parameters, with enhancements in speed, program memory capacity, and product status.

Parameter Comparison

Engineering Selection Recommendations

The AT89S8253-24AU is the qualified substitute for the AT89LS8252-12AC based on the following engineering criteria:

Product Status: The AT89LS8252-12AC is obsolete, creating supply chain risk. The AT89S8253-24AU maintains active product status with verified availability, ensuring long-term procurement viability.

Regulatory Compliance: The AT89S8253-24AU achieves ROHS3 compliance, meeting current environmental and regulatory standards. The original part is RoHS non-compliant, presenting compliance barriers for new designs.

Functional Enhancements: The substitute provides doubled clock speed (24MHz versus 12MHz) and increased program memory (12KB versus 8KB), delivering performance headroom without architectural changes.

Electrical Compatibility: Both devices share identical I/O count, EEPROM, RAM, and peripheral feature sets. The substitute's voltage supply range (2.7V ~ 5.5V) encompasses the critical lower threshold of the original specification.

Package Equivalence: Identical 44-TQFP (10x10) packaging ensures direct PCB compatibility without layout modifications.

Frequently Asked Questions (FAQ)

Q: Can the AT89S8253-24AU directly replace the AT89LS8252-12AC without firmware modification?

A: Yes. Both devices utilize the 8051 core processor with identical instruction sets. Firmware compiled for the AT89LS8252-12AC executes on the AT89S8253-24AU without modification. The increased clock speed and program memory of the substitute provide performance benefits without compatibility issues.

Q: What is the impact of the different voltage supply ranges?

A: The AT89LS8252-12AC operates at 2.7V ~ 6V, while the AT89S8253-24AU operates at 2.7V ~ 5.5V. If your application requires operation above 5.5V, the substitute is not suitable. For standard 3.3V or 5V supply designs, both parts are compatible.

Q: Does the external oscillator requirement of the AT89S8253-24AU affect circuit design?

A: The AT89LS8252-12AC uses an internal oscillator, while the AT89S8253-24AU requires an external oscillator. This represents a circuit design change requiring oscillator component addition and PCB layout modification for clock signal routing.

Q: Are the 44-TQFP packages mechanically identical?

A: Yes. Both parts use 44-TQFP (10x10) surface mount packaging with identical pin pitch, body dimensions, and lead configuration. No PCB footprint changes are required.

Q: What are the EEPROM and RAM implications for substitution?

A: Both devices provide identical EEPROM (2K x 8) and RAM (256 x 8) configurations. Applications utilizing these memory resources require no modification for the substitute part.

Q: How does the extended operating temperature range of the AT89S8253-24AU affect selection?

A: The AT89LS8252-12AC operates at 0°C ~ 70°C, while the AT89S8253-24AU operates at -40°C ~ 85°C. The substitute supports wider temperature extremes, providing design flexibility for industrial or extended-range applications without performance degradation.