AT89S51-24AI Equivalent & Substitute Parts

Part Overview

The AT89S51-24AI is an 8-bit microcontroller from Microchip Technology's 89S series, featuring 4KB FLASH program memory and operating at 24MHz. This device is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing design support and production requirements. The part is housed in a 44-TQFP surface mount package and operates across the industrial temperature range of -40°C to 85°C.

Substiute Parts

AT89S51-24AI

Microchip TechnologyIn Stock: 3939AT89S51-24AI Datasheet

Current PartRFQ

AT89S51-24AU

Microchip TechnologyIn Stock: 3052AT89S51-24AU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89S51-24AI is determined by strict equivalence across the following critical parameters:

• Core Architecture: 8051-based processor
• Memory Configuration: 4KB FLASH program memory, 128 x 8 RAM
• Operating Frequency: 24MHz
• Electrical Specifications: 4V ~ 5.5V supply voltage range
• I/O Count: 32 I/O pins
• Package Format: 44-TQFP (10x10) surface mount
• Peripheral Set: UART/USART connectivity and WDT functionality
• Temperature Range: -40°C to 85°C

The AT89S51-24AU meets all these criteria and is identified as a direct substitute. Both parts share identical base product number (AT89S51), core specifications, and functional capabilities.

Parameter Comparison

Engineering Selection Recommendations

The AT89S51-24AU is the direct functional equivalent of the AT89S51-24AI. Selection of the substitute part is supported by the following factors:

Product Status: The AT89S51-24AU carries Active product status, ensuring continued availability and manufacturer support, whereas the AT89S51-24AI is classified as Obsolete.

Regulatory Compliance: The AT89S51-24AU is ROHS3 compliant, meeting current environmental and regulatory requirements. The AT89S51-24AI is RoHS non-compliant, presenting potential compliance barriers for new designs and production.

Electrical and Functional Equivalence: Both parts maintain identical core specifications, memory configuration, operating frequency, supply voltage range, I/O count, package format, and peripheral functionality. No circuit redesign is required for substitution.

Programmability Verification: The AT89S51-24AU is verified as programmable through DiGi-Electronics, confirming production readiness and programming compatibility.

Frequently Asked Questions (FAQ)

Q: Can the AT89S51-24AU be used as a direct replacement for the AT89S51-24AI in existing designs?

A: Yes. Both parts are electrically and functionally identical across all specified parameters. No circuit modifications are required. The substitute part uses the same 44-TQFP package, operates at identical voltage and frequency specifications, and provides equivalent I/O and peripheral functionality.

Q: What is the difference between the AT89S51-24AI and AT89S51-24AU packaging?

A: The AT89S51-24AI is supplied in standard packaging, while the AT89S51-24AU is supplied in Tray packaging. Both use the same 44-TQFP (10x10) case format. The packaging difference does not affect electrical performance or pin compatibility.

Q: Why is the AT89S51-24AU preferred over the AT89S51-24AI?

A: The AT89S51-24AU is preferred due to Active product status and ROHS3 compliance. The AT89S51-24AI is Obsolete and RoHS non-compliant, which may create supply chain and regulatory challenges for new production.

Q: Are there any temperature or voltage operating differences between these parts?

A: No. Both parts operate identically across the -40°C to 85°C temperature range and 4V to 5.5V supply voltage range.

Q: What is the moisture sensitivity level for these parts?

A: Both the AT89S51-24AI and AT89S51-24AU have a Moisture Sensitivity Level (MSL) of 3, requiring storage and handling in accordance with 168-hour exposure limits.