AT89S53-24AC Equivalent & Substitute Parts

Part Overview

The AT89S53-24AC is an 8-bit microcontroller based on the 8051 core architecture, manufactured by Microchip Technology. This device integrates 12KB of FLASH program memory, 256 bytes of RAM, and 32 I/O pins in a 44-TQFP surface mount package. The AT89S53-24AC operates at 24MHz with a supply voltage range of 4V to 6V and an operating temperature range of 0°C to 70°C. The product is currently classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing system support and new designs.

Substiute Parts

AT89S53-24AC

Microchip TechnologyIn Stock: 2498AT89S53-24AC Datasheet

Current PartRFQ

AT89S8253-24AU

Microchip TechnologyIn Stock: 3045AT89S8253-24AU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89S53-24AC is determined by strict equivalence across the following critical parameters:

• Core Architecture: Both parts must implement the 8051 core processor
• Memory Configuration: Program memory must be 12KB FLASH with 256 x 8 RAM
• I/O Count: 32 I/O pins required
• Package: 44-TQFP (10x10) surface mount package
• Speed: 24MHz operation capability
• Connectivity: SPI and UART/USART interfaces must be present

The AT89S8253-24AU meets all these criteria and is identified as a manufacturer-recommended substitute. This part maintains full functional compatibility while offering enhanced specifications in voltage range, temperature range, and additional on-chip features.

Parameter Comparison

Engineering Selection Recommendations

The AT89S8253-24AU is the appropriate substitute for the obsolete AT89S53-24AC based on the following engineering criteria:

Functional Equivalence: Both devices share identical core architecture, memory configuration, I/O count, and package specifications. The AT89S8253-24AU maintains full pin and software compatibility with the AT89S53-24AC.

Product Status: The AT89S53-24AC is classified as obsolete, while the AT89S8253-24AU maintains active product status with verified availability. This ensures long-term supply chain reliability and continued manufacturer support.

Compliance and Certifications: The AT89S8253-24AU is ROHS3 compliant, whereas the AT89S53-24AC is non-compliant. For applications subject to RoHS regulations, the substitute part satisfies regulatory requirements.

Enhanced Specifications: The AT89S8253-24AU provides an extended voltage supply range (2.7V to 5.5V versus 4V to 6V) and expanded operating temperature range (-40°C to 85°C versus 0°C to 70°C). These enhancements support broader application environments without functional compromise.

Additional Features: The AT89S8253-24AU includes an integrated Power-On Reset (POR) circuit in addition to the Watchdog Timer (WDT) present in the original part, providing enhanced system reliability.

Frequently Asked Questions (FAQ)

Q: Are the AT89S53-24AC and AT89S8253-24AU pin-compatible?

A: Yes. Both devices use the 44-TQFP (10x10) package with identical pin assignments. Direct socket substitution is possible without PCB modifications.

Q: Can firmware developed for the AT89S53-24AC run on the AT89S8253-24AU without modification?

A: Yes. Both devices implement the same 8051 core architecture with identical program memory size (12KB FLASH) and RAM configuration (256 x 8). Existing firmware is fully compatible.

Q: What is the voltage supply difference between these parts?

A: The AT89S53-24AC operates at 4V to 6V, while the AT89S8253-24AU operates at 2.7V to 5.5V. The substitute part supports a wider voltage range, allowing operation in lower-voltage applications. Both ranges overlap at 4V to 5.5V, ensuring compatibility in standard 5V systems.

Q: Does the AT89S8253-24AU require different oscillator configuration?

A: The AT89S53-24AC uses an internal oscillator, while the AT89S8253-24AU requires an external oscillator. Circuit design must be updated to provide external clock generation for the substitute part.

Q: Is the AT89S8253-24AU suitable for new designs?

A: Yes. The AT89S8253-24AU is an active product with verified availability and ROHS3 compliance. It is the recommended choice for new designs requiring 8051-based microcontroller functionality in this memory and I/O configuration.

Q: What is the significance of the POR (Power-On Reset) feature in the AT89S8253-24AU?

A: The Power-On Reset circuit automatically initializes the microcontroller during power-up, ensuring predictable system startup behavior. This feature enhances system reliability compared to the AT89S53-24AC, which includes only the Watchdog Timer peripheral.