AT89LS8252-12PC Equivalent & Substitute Parts

Part Overview

The AT89LS8252-12PC is an 8051-based 8-bit microcontroller manufactured by Microchip Technology, featuring 8KB of FLASH program memory, 256 bytes of RAM, and 2KB of EEPROM. This device operates at 12MHz with a supply voltage range of 2.7V to 6V and includes integrated peripherals such as Power-On Reset (POR), Watchdog Timer (WDT), SPI, and UART/USART connectivity across 32 I/O pins in a 40-DIP package.

The AT89LS8252-12PC is classified as obsolete. Locating equivalent or substitute components is necessary for ongoing system maintenance, design updates, or production continuity when original inventory becomes unavailable.

Substiute Parts

AT89LS8252-12PC

Microchip TechnologyIn Stock: 1062AT89LS8252-12PC Datasheet

Current PartRFQ

AT89S52-24PU

Microchip TechnologyIn Stock: 10945AT89S52-24PU Datasheet

MFR RecommendedRFQ

AT89S8253-24PU

Microchip TechnologyIn Stock: 5635AT89S8253-24PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

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

Core Architecture Compatibility: All substitute parts must use the 8051 core processor and maintain 8-bit core size to ensure instruction set compatibility and firmware portability.

Memory Configuration: Program memory must be equal to or greater than 8KB FLASH. EEPROM presence (2KB x 8) is beneficial but not mandatory for basic substitution. RAM size of 256 x 8 bytes is standard across the 8051 family.

Electrical Compatibility: Supply voltage range must overlap with or encompass the original 2.7V ~ 6V specification. Operating temperature range should support the application's thermal requirements.

Package and Pinout: All substitutes must use the 40-DIP package with identical pinout to ensure direct board-level replacement without layout modifications.

I/O and Connectivity: 32 I/O pins and UART/USART connectivity are baseline requirements. SPI support is desirable but not mandatory.

Peripherals: Watchdog Timer (WDT) is standard. Power-On Reset (POR) support is beneficial for system reliability.

Parameter Comparison

Engineering Selection Recommendations

AT89S52-24PU is suitable for applications where EEPROM is not required and SPI connectivity is not essential. This part operates at 24MHz, providing doubled processing speed compared to the original. The supply voltage range of 4V ~ 5.5V is narrower than the original specification; applications requiring operation below 4V are not compatible. This device is active and ROHS3 compliant, supporting long-term availability and regulatory compliance.

AT89S8253-24PU is the preferred substitute when EEPROM retention and SPI connectivity are required. This part maintains the 2KB x 8 EEPROM and includes both SPI and UART/USART interfaces, matching the original peripheral set. The supply voltage range of 2.7V ~ 5.5V encompasses the lower voltage operation of the original specification. Operating temperature range extends to -40°C ~ 85°C, supporting wider thermal environments. This device is active and ROHS3 compliant. Program memory is increased to 12KB, providing additional code space without architectural changes.

Both substitutes maintain the 40-DIP package, 32 I/O pins, and 8051 core architecture, ensuring direct replacement capability at the board level.

Frequently Asked Questions (FAQ)

Q: Can AT89S52-24PU directly replace AT89LS8252-12PC?

A: Direct replacement is possible from a pinout and package perspective. However, the absence of EEPROM in the AT89S52-24PU requires firmware verification if the original application relies on EEPROM storage. The narrower supply voltage range (4V ~ 5.5V versus 2.7V ~ 6V) must be evaluated against system power requirements.

Q: What is the impact of the 24MHz speed increase in substitute parts?

A: The doubled clock frequency in both AT89S52-24PU and AT89S8253-24PU increases instruction execution speed proportionally. Timing-dependent code, interrupt handlers, and serial communication baud rates may require adjustment. Firmware recompilation is not necessary, but timing validation is recommended.

Q: Why does AT89S8253-24PU have 12KB program memory instead of 8KB?

A: The AT89S8253-24PU is a higher-capacity variant within the 89S series. The additional 4KB of FLASH memory does not affect compatibility; existing firmware compiled for 8KB operates without modification. The expanded memory space is available for future code expansion.

Q: Is the absence of Power-On Reset (POR) in AT89S52-24PU a compatibility issue?

A: POR is a system initialization feature that automatically resets the microcontroller during power-up. The AT89S52-24PU lacks integrated POR; external reset circuitry may be required depending on application requirements. AT89S8253-24PU includes POR, matching the original specification.

Q: Are both substitute parts RoHS compliant?

A: Yes. Both AT89S52-24PU and AT89S8253-24PU are ROHS3 compliant. The original AT89LS8252-12PC is RoHS non-compliant. Substitution with either active part satisfies RoHS regulatory requirements for new designs or production updates.

Q: What is the difference between oscillator types (Internal vs. External)?

A: The original AT89LS8252-12PC uses an internal oscillator. AT89S8253-24PU specifies external oscillator type, requiring an external crystal or clock source for operation. AT89S52-24PU uses an internal oscillator. External oscillator configuration may require PCB modifications if the original design does not include crystal support.