AT89LS8252-12JC Equivalent & Substitute Parts

Part Overview

The AT89LS8252-12JC is an 8051-based 8-bit microcontroller manufactured by Microchip Technology, featuring 8KB FLASH program memory, 2KB EEPROM, and 256 bytes of RAM. Operating at 12MHz with a 44-PLCC package, this device integrates SPI and UART/USART connectivity alongside Power-On Reset (POR) and Watchdog Timer (WDT) peripherals. The product is classified as obsolete, necessitating identification of functionally compatible alternatives for ongoing system support and new designs.

Substiute Parts

AT89LS8252-12JC

Microchip TechnologyIn Stock: 774AT89LS8252-12JC Datasheet

Current PartRFQ

AT89S8253-24JU

Microchip TechnologyIn Stock: 2579AT89S8253-24JU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89LS8252-12JC is determined by strict compatibility across the following parameters:

Core Architecture & Instruction Set: Both devices must utilize the 8051 core processor and 8-bit architecture to ensure firmware compatibility without recompilation.

Package & Pinout: The 44-LCC (J-Lead) package with identical pin configuration (44-PLCC 16.6x16.6) is mandatory for direct board-level replacement.

Memory Configuration: Program memory (FLASH), EEPROM, and RAM sizes must meet or exceed the original specifications to support existing firmware and data storage requirements.

Electrical Characteristics: Supply voltage range, I/O count, and peripheral set (SPI, UART/USART, POR, WDT) must be compatible with the application circuit.

Connectivity & Peripherals: SPI and UART/USART interfaces, along with POR and WDT functions, must be present to maintain system functionality.

The AT89S8253-24JU qualifies as a substitute based on these criteria, offering enhanced specifications while maintaining core compatibility.

Parameter Comparison

Engineering Selection Recommendations

AT89S8253-24JU is the qualified substitute for AT89LS8252-12JC based on the following engineering criteria:

Product Status: The AT89S8253-24JU is in active production status, ensuring long-term availability and supply chain continuity. The original AT89LS8252-12JC is obsolete, making the substitute necessary for ongoing support.

Compliance & Certifications: The AT89S8253-24JU is ROHS3 compliant and REACH unaffected, meeting current regulatory requirements. The original part is RoHS non-compliant, presenting compliance risks for new designs and procurement.

Core Compatibility: Both devices share the 8051 core architecture, identical I/O count (32), and matching peripheral sets (SPI, UART/USART, POR, WDT), ensuring firmware compatibility without modification.

Package & Pinout: Identical 44-LCC (J-Lead) package configuration enables direct board-level replacement without PCB redesign.

Memory Specifications: The substitute provides 12KB FLASH (versus 8KB original) and maintains identical EEPROM (2K x 8) and RAM (256 x 8) sizes, supporting existing firmware with additional capacity for future enhancements.

Electrical Considerations: Supply voltage range differs at the upper limit (5.5V substitute versus 6V original). Applications operating above 5.5V require circuit modification or alternative selection. Operating temperature range is extended (-40°C to 85°C versus 0°C to 70°C), providing broader environmental capability.

Speed Differential: The substitute operates at 24MHz versus 12MHz original. Applications with timing-dependent code or delay loops require functional validation to ensure correct operation at the higher clock frequency.

Frequently Asked Questions (FAQ)

Q: Can the AT89S8253-24JU directly replace the AT89LS8252-12JC without PCB modification?

A: Yes, for board-level replacement. Both devices use the 44-LCC (J-Lead) package with identical pinout and footprint. However, if the application circuit supplies voltage above 5.5V, the power supply circuit must be modified to meet the substitute's 2.7V to 5.5V specification.

Q: Will existing firmware run on the AT89S8253-24JU without recompilation?

A: Firmware compiled for the 8051 architecture will execute on the substitute without recompilation. However, code containing timing-dependent functions (delay loops, baud rate calculations, interrupt timing) must be validated at the higher 24MHz clock frequency to ensure correct operation.

Q: What are the key differences between these two parts?

A: The AT89S8253-24JU offers higher clock speed (24MHz versus 12MHz), increased FLASH memory (12KB versus 8KB), extended operating temperature range (-40°C to 85°C versus 0°C to 70°C), and current product status with RoHS3 compliance. The original AT89LS8252-12JC is obsolete and RoHS non-compliant.

Q: Is the AT89S8253-24JU suitable for applications requiring the full 6V supply voltage range?

A: No. The substitute operates within 2.7V to 5.5V. Applications requiring operation above 5.5V must either modify the power supply circuit to limit voltage to 5.5V or select an alternative component with a 6V maximum rating.

Q: What is the impact of the 24MHz clock speed on system design?

A: The doubled clock frequency increases instruction execution speed, reducing code execution time by approximately 50% for equivalent operations. Applications with timing-dependent functions (UART baud rate generation, PWM timing, sensor sampling intervals) require recalibration or functional testing to ensure correct behavior.

Q: Are the memory sizes compatible with existing firmware?

A: Yes. The substitute provides equal or greater memory capacity: 12KB FLASH (exceeds 8KB requirement), 2KB EEPROM (identical), and 256 bytes RAM (identical). Existing firmware will fit within the substitute's memory configuration.

Q: Does the substitute support the same peripheral interfaces?

A: Yes. Both devices include SPI and UART/USART connectivity, along with Power-On Reset (POR) and Watchdog Timer (WDT) peripherals. Peripheral functionality is compatible.