AT89LS51-16AI Equivalent & Substitute Parts

Part Overview

The AT89LS51-16AI 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 in a 44-TQFP surface mount package. Operating at 16MHz with a supply voltage range of 2.7V to 4V, the AT89LS51-16AI is designed for embedded control applications requiring low-power operation and integrated UART/USART connectivity.

The AT89LS51-16AI carries an Obsolete product status. Locating equivalent substitute parts is necessary to maintain design continuity, ensure supply chain reliability, and support ongoing production or maintenance requirements for systems utilizing this microcontroller.

Substiute Parts

AT89LS51-16AI

Microchip TechnologyIn Stock: 2420AT89LS51-16AI Datasheet

Current PartRFQ

AT89LS51-16AU

Microchip TechnologyIn Stock: 4171AT89LS51-16AU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution eligibility for the AT89LS51-16AI 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
• Clock Speed: 16MHz operation
• I/O Count: 32 I/O pins
• Supply Voltage: 2.7V to 4V range
• Package: 44-TQFP (10x10) surface mount
• Thermal Range: -40°C to 85°C operating temperature
• Connectivity & Peripherals: UART/USART and WDT functionality

The AT89LS51-16AU meets all substitution criteria as a direct equivalent, maintaining identical electrical specifications, memory architecture, pin configuration, and functional capabilities while offering improved product status and compliance certifications.

Parameter Comparison

Engineering Selection Recommendations

The AT89LS51-16AU is the direct substitute for the AT89LS51-16AI. Both devices are electrically and functionally identical across all specified parameters. The AT89LS51-16AU offers the following advantages:

• Active Product Status: The AT89LS51-16AU maintains active production status, ensuring long-term availability and supply chain stability compared to the obsolete AT89LS51-16AI.
• RoHS3 Compliance: The AT89LS51-16AU meets ROHS3 compliance requirements, whereas the AT89LS51-16AI is RoHS non-compliant. This distinction is critical for applications subject to environmental and regulatory standards.
• Verified Programmability: The AT89LS51-16AU is verified as programmable through DiGi-Electronics channels, supporting production and field programming workflows.

Selection of the AT89LS51-16AU eliminates obsolescence risk while maintaining full electrical and functional compatibility with designs originally specified for the AT89LS51-16AI.

Frequently Asked Questions (FAQ)

Q: Are the AT89LS51-16AI and AT89LS51-16AU pin-compatible?

A: Yes. Both devices use the 44-TQFP (10x10) package with identical pin assignments, I/O configuration, and functional pinout. Direct PCB-level substitution is supported without layout modifications.

Q: What is the difference between the AT89LS51-16AI and AT89LS51-16AU?

A: The devices are electrically and functionally equivalent. The primary differences are product status (Obsolete vs. Active), RoHS compliance (non-compliant vs. ROHS3 Compliant), and programmability verification status. The AT89LS51-16AU is the recommended substitute for new designs and ongoing production.

Q: Can I use the AT89LS51-16AU as a direct replacement in existing systems?

A: Yes. The AT89LS51-16AU is a direct functional and electrical equivalent. No firmware modifications, circuit redesign, or application software changes are required. The device operates identically within the specified voltage, temperature, and clock speed parameters.

Q: What does RoHS3 compliance mean for the AT89LS51-16AU?

A: ROHS3 compliance indicates the device meets Restriction of Hazardous Substances Directive requirements, restricting the use of specific hazardous materials in electrical and electronic equipment. This is relevant for applications subject to EU environmental regulations or customer-mandated compliance standards.

Q: Is the moisture sensitivity level the same for both parts?

A: Yes. Both the AT89LS51-16AI and AT89LS51-16AU carry MSL 3 (168 Hours) rating, indicating identical moisture handling and storage requirements during manufacturing and assembly processes.

Q: What supply voltage range do these microcontrollers support?

A: Both devices operate across a 2.7V to 4V supply voltage range, supporting low-power battery-operated applications and standard 3.3V logic systems without external voltage regulation.