AT87F51RC-24PI Equivalent & Substitute Parts

Part Overview

The AT87F51RC-24PI is an 8-bit microcontroller from Microchip Technology based on the 8051 core architecture. This device features 32KB of OTP Quick FLASH program memory, 512 x 8 bytes of RAM, and operates at 24MHz with a supply voltage range of 4V to 6V. The part is mounted in a 40-DIP package and includes UART/USART connectivity and watchdog timer peripherals.

The AT87F51RC-24PI is classified as obsolete. Equivalent and substitute parts are necessary to support ongoing system maintenance, production continuity, and design updates where the original part is no longer available from primary sources.

Substiute Parts

AT87F51RC-24PI

Microchip TechnologyIn Stock: 1428AT87F51RC-24PI Datasheet

Current PartRFQ

W78E058DDG

Nuvoton Technology CorporationIn Stock: 7496W78E058DDG Datasheet

MFR RecommendedRFQ

W78E516DDG

Nuvoton Technology CorporationIn Stock: 3670W78E516DDG Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT87F51RC-24PI is determined by the following critical parameters:

Core Architecture Compatibility: Both substitute parts use the 8052 core processor, which is backward compatible with 8051-based designs. The 8052 core includes all 8051 instruction set functionality with extended capabilities.

Memory Configuration: The AT87F51RC-24PI requires 32KB program memory. Substitute parts must provide a minimum of 32KB program memory capacity. The W78E058DDG provides exactly 32KB, while the W78E516DDG provides 64KB, which is compatible for applications requiring equal or greater memory.

Package and Pin Configuration: Both substitute parts are housed in 40-DIP packages with identical pin counts and I/O configuration (32 I/O lines), ensuring mechanical and electrical compatibility with existing PCB layouts.

Voltage Supply Range: The AT87F51RC-24PI operates at 4V to 6V. The substitute parts operate at 2.4V to 5.5V, which encompasses the original operating range and provides extended low-voltage capability.

Operating Temperature Range: Both substitute parts maintain the -40°C to 85°C operating temperature range, matching the original specification.

Memory Type: The original part uses OTP Quick FLASH. Substitute parts use standard FLASH memory, which is functionally equivalent for application purposes.

Parameter Comparison

Engineering Selection Recommendations

W78E058DDG is the direct functional equivalent for applications requiring exactly 32KB program memory. This part is currently in active production status with ROHS3 compliance certification. The W78E058DDG operates at 40MHz, providing performance headroom above the original 24MHz specification. The extended voltage range (2.4V to 5.5V) accommodates the original 4V to 6V requirement. This part is suitable for direct replacement in existing designs without memory expansion requirements.

W78E516DDG is appropriate for applications where expanded program memory capacity (64KB) is beneficial or required. This part is also in active production status with ROHS3 compliance certification and operates at 40MHz. The W78E516DDG is compatible with the AT87F51RC-24PI pin configuration and operating parameters, with the advantage of doubled program memory capacity. This part is suitable for designs requiring additional code space or future firmware expansion.

Both substitute parts are manufactured by Nuvoton Technology Corporation and maintain active product status, ensuring long-term availability and supply chain continuity compared to the obsolete original part.

Frequently Asked Questions (FAQ)

Q: Can the W78E058DDG or W78E516DDG be used as direct replacements for the AT87F51RC-24PI?

A: Yes. Both parts are compatible replacements. The W78E058DDG provides equivalent 32KB program memory capacity. The W78E516DDG provides 64KB program memory, which is compatible for any application using the original 32KB part. All three parts share identical 40-DIP package configuration, 32 I/O lines, 512 x 8 RAM, and -40°C to 85°C operating temperature range.

Q: What is the difference between the two substitute parts?

A: The primary difference is program memory capacity. The W78E058DDG provides 32KB (matching the original), while the W78E516DDG provides 64KB. Both operate at 40MHz and are pin-compatible with the AT87F51RC-24PI. The W78E516DDG is suitable for applications requiring additional code space.

Q: Are there voltage supply differences between the original and substitute parts?

A: The AT87F51RC-24PI operates at 4V to 6V. Both substitute parts operate at 2.4V to 5.5V. The substitute range encompasses the original specification and extends lower voltage capability. Designs operating within the original 4V to 6V range are fully compatible with both substitute parts.

Q: What is the significance of the 8052 core in the substitute parts versus the 8051 core in the original?

A: The 8052 core is backward compatible with 8051 instruction set and architecture. All 8051 software and firmware execute identically on 8052-based devices. The 8052 core includes additional features such as Power-On Reset (POR) functionality, which is present in both substitute parts.

Q: Are the substitute parts RoHS compliant?

A: Yes. Both W78E058DDG and W78E516DDG are ROHS3 compliant. The original AT87F51RC-24PI is RoHS non-compliant. Designs requiring RoHS compliance must use one of the substitute parts.

Q: What is the operating speed difference, and does it affect compatibility?

A: The original part operates at 24MHz, while both substitute parts operate at 40MHz. The higher speed of the substitute parts is compatible with the original design. Applications designed for 24MHz operation function correctly at 40MHz. The increased speed provides performance headroom and does not introduce compatibility issues.

Q: Can firmware developed for the AT87F51RC-24PI run on the substitute parts without modification?

A: Yes. Firmware developed for the 8051 core executes on the 8052-based substitute parts without modification. The 8052 core maintains full backward compatibility with 8051 instruction set and memory organization.