AT87C51RB2-3CSUM Equivalent & Substitute Parts

Part Overview

The AT87C51RB2-3CSUM is an 80C51-based 8-bit microcontroller featuring 16KB OTP (One-Time Programmable) memory, manufactured by Microchip Technology. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing design support and production continuity. The part operates at 40/20MHz with 32 I/O pins in a 40-PDIL package and supports standard 8051 peripherals including UART/USART, PWM, and watchdog timer functionality.

Substiute Parts

AT87C51RB2-3CSUM

Microchip TechnologyIn Stock: 2230AT87C51RB2-3CSUM Datasheet

Current PartRFQ

AT89C51RB2-3CSUM

Microchip TechnologyIn Stock: 1225AT89C51RB2-3CSUM Datasheet

MFR RecommendedRFQ

DS87C520-MCL+

Analog Devices Inc./Maxim IntegratedIn Stock: 2458DS87C520-MCL+ Datasheet

MFR RecommendedRFQ

DS87C520-MNL+

Analog Devices Inc./Maxim IntegratedIn Stock: 1279DS87C520-MNL+ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the AT87C51RB2-3CSUM is determined by the following critical parameters: 80C51-compatible core processor architecture, 16KB program memory capacity, 40-pin DIP package format, and through-hole mounting. The substitute parts are grouped into two categories based on memory technology:

Category 1 - FLASH Memory Technology (Active Status): AT89C51RB2-3CSUM represents an active-status alternative with FLASH memory instead of OTP, offering higher speed (60MHz) and extended voltage range (2.7V ~ 5.5V). This part maintains 80C51 core compatibility and identical I/O count.

Category 2 - OTP Memory Technology (Active Status): DS87C520-MCL+ and DS87C520-MNL+ are 8051-based alternatives with OTP memory matching the original technology. Both maintain 16KB program memory, 40-pin DIP packaging, and core processor compatibility. These parts operate at 33MHz with extended connectivity options (EBI/EMI, SIO).

Parameter Comparison

Engineering Selection Recommendations

AT89C51RB2-3CSUM Selection Criteria: This substitute is recommended for applications requiring FLASH memory reprogrammability and extended voltage tolerance (2.7V ~ 5.5V). The active product status ensures long-term availability and manufacturing support. Higher operating speed (60MHz) and improved RAM capacity (1.25K x 8) provide performance advantages. MSL rating of 1 indicates superior moisture resistance compared to the original part.

DS87C520-MCL+ Selection Criteria: This substitute maintains OTP memory technology identical to the original part, suitable for applications where FLASH capability is not required. Active product status and ROHS3 compliance ensure regulatory compliance. Operating temperature range is limited to 0°C ~ 70°C, requiring verification against application requirements. MSL rating of 1 provides improved moisture handling.

DS87C520-MNL+ Selection Criteria: This substitute provides OTP memory technology with extended operating temperature range (-40°C ~ 85°C) matching the original part specification. Active product status and ROHS3 compliance are maintained. MSL rating of 1 indicates superior moisture resistance. This option is optimal for temperature-critical applications requiring OTP memory.

Frequently Asked Questions (FAQ)

Q: Can AT89C51RB2-3CSUM directly replace AT87C51RB2-3CSUM in existing designs? A: Yes, with design considerations. Both parts share 80C51 core architecture, 16KB program memory, 32 I/O pins, and 40-DIP packaging. The primary difference is memory technology (FLASH vs. OTP). Voltage supply range differs (2.7V ~ 5.5V vs. 4.5V ~ 5.5V), allowing operation at lower voltages. Code compatibility is maintained for standard 8051 instruction sets.

Q: What are the key differences between OTP and FLASH memory substitutes? A: OTP (One-Time Programmable) memory cannot be erased after programming, suitable for production-locked designs. FLASH memory is reprogrammable, enabling field updates and development flexibility. AT89C51RB2-3CSUM uses FLASH technology, while DS87C520 variants use OTP. Select based on reprogramming requirements.

Q: Are the DS87C520 variants interchangeable with each other? A: DS87C520-MCL+ and DS87C520-MNL+ are functionally equivalent with identical electrical specifications. The primary difference is operating temperature range: DS87C520-MCL+ operates 0°C ~ 70°C, while DS87C520-MNL+ operates -40°C ~ 85°C. Select based on application temperature requirements.

Q: Does the 40-DIP package format remain consistent across all substitutes? A: Yes. All substitute parts maintain the 40-DIP (0.600", 15.24mm) package format with through-hole mounting, ensuring direct PCB compatibility without layout modifications.

Q: What compliance certifications apply to these substitute parts? A: All substitute parts are ROHS3 compliant and REACH unaffected, matching the original part's regulatory status. Moisture sensitivity levels vary: original part MSL 3 (168 hours), substitutes MSL 1 (unlimited), indicating improved moisture resistance in substitute options.

Q: How does RAM capacity affect substitution suitability? A: Original part provides 512 x 8 RAM. AT89C51RB2-3CSUM offers 1.25K x 8, and DS87C520 variants offer 1K x 8. Increased RAM capacity in substitutes provides additional working memory without affecting core functionality. Applications requiring specific RAM sizes should verify compatibility.