AT89S8253-24AI Equivalent & Substitute Parts

Part Overview

The AT89S8253-24AI is an 8-bit microcontroller from Microchip Technology's 89S series, featuring 12KB FLASH program memory, 2KB EEPROM, and 256 bytes of RAM. This device operates at 24MHz with a supply voltage range of 2.7V to 5.5V and is housed in a 44-TQFP surface mount package. The part is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing system support and new design implementations where this architecture remains applicable.

Substiute Parts

AT89S8253-24AI

Microchip TechnologyIn Stock: 3686AT89S8253-24AI Datasheet

Current PartRFQ

AT89S8253-24AU

Microchip TechnologyIn Stock: 3045AT89S8253-24AU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89S8253-24AI is determined by strict equivalence across the following critical parameters:

• Core processor architecture (8051)
• Core size (8-Bit)
• Operating frequency (24MHz)
• Program memory capacity and type (12KB FLASH)
• EEPROM capacity (2K x 8)
• RAM capacity (256 x 8)
• I/O count (32 pins)
• Connectivity interfaces (SPI, UART/USART)
• Peripheral features (POR, WDT)
• Supply voltage range (2.7V ~ 5.5V)
• Operating temperature range (-40°C ~ 85°C)
• Package type (44-TQFP)

The AT89S8253-24AU meets all these criteria and is therefore a direct functional equivalent. The primary distinction between these parts lies in packaging format (tray vs. standard) and product status (active vs. obsolete).

Parameter Comparison

Engineering Selection Recommendations

The AT89S8253-24AU is the direct functional equivalent of the AT89S8253-24AI. Both devices are pin-compatible and electrically identical across all specified parameters. Selection between these parts should be based on the following factors:

Product Status: The AT89S8253-24AU carries an active product status, ensuring continued availability and manufacturer support. The AT89S8253-24AI is obsolete and subject to inventory depletion.

Regulatory Compliance: The AT89S8253-24AU is ROHS3 compliant, meeting current environmental and regulatory requirements for new designs and procurement. The AT89S8253-24AI is RoHS non-compliant.

Packaging: The AT89S8253-24AU is supplied in tray packaging, while the AT89S8253-24AI uses standard packaging. Packaging selection depends on assembly process requirements and handling procedures.

For new designs or systems requiring long-term component availability and regulatory compliance, the AT89S8253-24AU is the appropriate selection. For legacy system maintenance where existing inventory of the AT89S8253-24AI is available, direct substitution is electrically and functionally valid.

Frequently Asked Questions (FAQ)

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

A: Yes. Both devices use the 44-TQFP (10x10) package with identical pinout and electrical characteristics. Direct substitution on the PCB is possible without design modification.

Q: What is the difference between the two part numbers?

A: The primary differences are product status (obsolete vs. active), RoHS compliance (non-compliant vs. ROHS3 compliant), and packaging format (standard vs. tray). All electrical and functional parameters are identical.

Q: Can I use the AT89S8253-24AU as a replacement in existing systems designed for the AT89S8253-24AI?

A: Yes. The AT89S8253-24AU is a direct functional equivalent with identical electrical specifications, memory configuration, I/O count, and peripheral features. No firmware or hardware modifications are required.

Q: What does the packaging format difference mean for assembly?

A: Tray packaging is typically used for automated pick-and-place assembly processes, while standard packaging may be used for manual or alternative assembly methods. The actual component is identical; only the delivery format differs.

Q: Why is the AT89S8253-24AI classified as obsolete?

A: Microchip Technology has transitioned this product line to the active AT89S8253-24AU variant. The obsolete designation indicates that the original part number is no longer in active production, though existing inventory may remain available.

Q: Are there any performance differences between these parts?

A: No. Both parts operate at 24MHz, support the same voltage range (2.7V ~ 5.5V), provide identical memory resources (12KB FLASH, 2KB EEPROM, 256 bytes RAM), and include the same peripheral features (SPI, UART/USART, POR, WDT).