AT89S51-24AC Equivalent & Substitute Parts

Part Overview

The AT89S51-24AC 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 is suitable for embedded applications requiring UART/USART connectivity and watchdog timer functionality.

Substiute Parts

AT89S51-24AC

Microchip TechnologyIn Stock: 1093AT89S51-24AC Datasheet

Current PartRFQ

AT89S51-24AU

Microchip TechnologyIn Stock: 3052AT89S51-24AU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89S51-24AC 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 and WDT functionality

The AT89S51-24AU meets all these criteria and is therefore a direct functional equivalent. Both parts share identical core specifications, memory architecture, and pinout configuration, enabling direct substitution at the component level.

Parameter Comparison

Engineering Selection Recommendations

The AT89S51-24AU is the direct substitute for the AT89S51-24AC. Both parts are functionally identical across all electrical and mechanical parameters specified for this product category.

Product Status Consideration: The AT89S51-24AC is obsolete, while the AT89S51-24AU is active. Selection of the AT89S51-24AU ensures continued availability and manufacturing support.

Compliance Advantage: The AT89S51-24AU is ROHS3 compliant, whereas the AT89S51-24AC is non-compliant. This distinction is relevant for applications subject to RoHS regulations.

Operating Temperature Range: The AT89S51-24AU supports an extended operating temperature range of -40°C ~ 85°C compared to the AT89S51-24AC range of 0°C ~ 70°C. This provides greater thermal flexibility for demanding environments.

Packaging: The AT89S51-24AU is supplied in Tray packaging, while the AT89S51-24AC packaging is unspecified. Both maintain identical 44-TQFP (10x10) case geometry.

Frequently Asked Questions (FAQ)

Q: Can the AT89S51-24AU directly replace the AT89S51-24AC in existing designs?

A: Yes. Both parts share identical core architecture, memory configuration, I/O count, and package format. No design modifications are required for substitution.

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

A: The primary differences are product status (obsolete vs. active), RoHS compliance (non-compliant vs. ROHS3 compliant), and operating temperature range (0°C ~ 70°C vs. -40°C ~ 85°C). All functional and electrical specifications are identical.

Q: Are there any pinout differences between these parts?

A: No. Both parts use the 44-TQFP (10x10) package with identical pinout configuration and 32 I/O pins.

Q: Does the extended temperature range of the AT89S51-24AU affect compatibility?

A: No. The extended range of the AT89S51-24AU is a superset of the AT89S51-24AC range. Applications designed for 0°C ~ 70°C operation remain fully compatible.

Q: Is the AT89S51-24AU suitable for RoHS-regulated applications?

A: Yes. The AT89S51-24AU is ROHS3 compliant, making it suitable for applications subject to RoHS directives. The AT89S51-24AC is not RoHS compliant.

Q: What packaging options are available for the substitute part?

A: The AT89S51-24AU is supplied in Tray packaging. Both parts maintain the same 44-TQFP (10x10) case geometry for PCB assembly.