AT89LS51-16AC Equivalent & Substitute Parts

Part Overview

The AT89LS51-16AC is an 8-bit microcontroller based on the 8051 core architecture, manufactured by Microchip Technology. This device integrates 4KB of FLASH program memory, 128 bytes of RAM, and 32 I/O pins, operating at 16MHz with a supply voltage range of 2.7V to 4V. The part is classified as obsolete, which necessitates identification of functionally equivalent alternatives for ongoing design support and production requirements.

Substiute Parts

AT89LS51-16AC

Microchip TechnologyIn Stock: 17774AT89LS51-16AC Datasheet

Current PartRFQ

AT89LS51-16AU

Microchip TechnologyIn Stock: 4171AT89LS51-16AU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89LS51-16AC is determined by strict equivalence across the following critical parameters:

• Core Architecture: 8051-based processor
• Memory Configuration: 4KB FLASH program memory, 128 bytes RAM
• Clock Speed: 16MHz operation
• I/O Count: 32 I/O pins
• Package: 44-TQFP (10x10) surface mount
• Supply Voltage: 2.7V ~ 4V range
• Connectivity: UART/USART interface
• Peripherals: Watchdog Timer (WDT)

The AT89LS51-16AU meets all these criteria and is identified as a manufacturer-recommended substitute. Both parts share identical core functionality, memory architecture, and pinout configuration, enabling direct replacement in existing designs.

Parameter Comparison

Engineering Selection Recommendations

The AT89LS51-16AU is the direct functional equivalent of the AT89LS51-16AC and serves as the manufacturer-recommended substitute. Selection of the AT89LS51-16AU is justified on the following grounds:

Product Status: The AT89LS51-16AC is classified as obsolete, while the AT89LS51-16AU maintains active product status with ongoing manufacturer support and availability.

Regulatory Compliance: The AT89LS51-16AU is ROHS3 compliant, meeting current environmental and regulatory requirements. The original AT89LS51-16AC is RoHS non-compliant, presenting compliance risks for new designs and production.

Operating Temperature Range: The AT89LS51-16AU provides an extended operating temperature range of -40°C to 85°C, compared to the AT89LS51-16AC range of 0°C to 70°C. This extended range accommodates broader application environments without functional degradation.

Functional Equivalence: Both devices share identical core architecture, memory configuration, I/O count, clock speed, and package specifications, ensuring pin-for-pin and code-level compatibility.

Packaging: The AT89LS51-16AU is supplied in Tray packaging, while the AT89LS51-16AC designation reflects different packaging. Both use the 44-TQFP (10x10) surface mount package.

Frequently Asked Questions (FAQ)

Q: Can the AT89LS51-16AU be used as a direct replacement for the AT89LS51-16AC?

A: Yes. Both devices are functionally equivalent with identical core processor architecture, memory configuration, I/O pin count, clock speed, and 44-TQFP package. No circuit modifications are required for substitution.

Q: What is the primary reason for substituting the AT89LS51-16AC?

A: The AT89LS51-16AC is classified as obsolete. The AT89LS51-16AU is the active equivalent, ensuring continued availability, manufacturer support, and compliance with current regulatory standards.

Q: Are there differences in operating temperature specifications?

A: Yes. The AT89LS51-16AU operates across -40°C to 85°C, while the AT89LS51-16AC operates across 0°C to 70°C. The extended range of the AT89LS51-16AU provides greater flexibility for temperature-sensitive applications.

Q: Does the AT89LS51-16AU meet RoHS compliance requirements?

A: Yes. The AT89LS51-16AU is ROHS3 compliant. The AT89LS51-16AC is RoHS non-compliant. For new designs and production requiring RoHS compliance, the AT89LS51-16AU is the appropriate selection.

Q: Are the pin configurations identical between these parts?

A: Yes. Both devices use the 44-TQFP (10x10) surface mount package with identical pinout and I/O configuration. No PCB layout modifications are necessary.

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

A: Both the AT89LS51-16AC and AT89LS51-16AU have a Moisture Sensitivity Level (MSL) of 3, with a floor life of 168 hours. Identical handling and storage protocols apply to both devices.

Q: Is firmware compatibility maintained between these parts?

A: Yes. Both devices use the identical 8051 core architecture with the same instruction set, memory organization, and peripheral configuration. Existing firmware requires no modification.