AT87C52X2-SLSUL Equivalent & Substitute Parts

Part Overview

The AT87C52X2-SLSUL is an 80C51-based 8-bit microcontroller manufactured by Microchip Technology, featuring 8KB OTP (One-Time Programmable) memory in a 44-PLCC surface mount package. This device operates at 30/20MHz with a supply voltage range of 2.7V to 5.5V and includes 32 I/O pins and 256 x 8 bytes of RAM.

The AT87C52X2-SLSUL is classified as obsolete. Finding equivalent or substitute parts is necessary to support legacy system maintenance, design updates, or when original inventory becomes unavailable. Substitute parts must maintain core processor compatibility (80C51 architecture), identical pinout (44-PLCC), matching I/O count (32 pins), and compatible voltage specifications to ensure drop-in replacement capability.

Substiute Parts

AT87C52X2-SLSUL

Microchip TechnologyIn Stock: 928AT87C52X2-SLSUL Datasheet

Current PartRFQ

AT89C51RB2-SLSUM

Microchip TechnologyIn Stock: 3642AT89C51RB2-SLSUM Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT87C52X2-SLSUL is determined by the following critical parameters:

Core Architecture Compatibility: Both the main part and substitute must use the 80C51 core processor to ensure instruction set compatibility and software portability.

Pinout & Package: The 44-PLCC (44-LCC J-Lead) package with 32 I/O pins must be maintained for mechanical and electrical compatibility with existing PCB layouts.

Voltage Specification: Supply voltage range of 2.7V ~ 5.5V must be supported to ensure operation within the same power supply constraints.

Memory Architecture: While program memory type and size may differ (OTP vs. FLASH), the substitute must support the same address space and memory access patterns required by 80C51-based applications.

Operating Temperature Range: The -40°C ~ 85°C specification must be maintained for thermal compatibility.

The AT89C51RB2-SLSUM qualifies as a substitute based on these criteria: it maintains the 80C51 core, uses the identical 44-PLCC package with 32 I/O pins, supports the same 2.7V ~ 5.5V supply voltage, and operates within the same temperature range. The upgrade from OTP to FLASH memory and increased program memory (16KB vs. 8KB) provides enhanced functionality while maintaining full backward compatibility.

Parameter Comparison

Engineering Selection Recommendations

AT89C51RB2-SLSUM is the qualified substitute for AT87C52X2-SLSUL based on the following engineering criteria:

Product Status: The AT87C52X2-SLSUL is obsolete, while the AT89C51RB2-SLSUM is active. Active product status ensures continued availability, manufacturing support, and compliance with current industry standards.

Compliance & Certifications: Both parts maintain ROHS3 compliance and REACH unaffected status, ensuring regulatory alignment for new designs and legacy system updates.

Functional Compatibility: The 80C51 core processor, identical pinout (44-PLCC, 32 I/O), matching voltage specification (2.7V ~ 5.5V), and equivalent operating temperature range (-40°C ~ 85°C) provide direct compatibility with existing circuit designs and firmware.

Enhanced Capabilities: The AT89C51RB2-SLSUM offers superior specifications including FLASH memory (enabling in-system reprogrammability versus one-time programming), doubled program memory (16KB vs. 8KB), and increased RAM (1.25K x 8 vs. 256 x 8), supporting more complex applications without design modification.

Frequently Asked Questions (FAQ)

Q: Can the AT89C51RB2-SLSUM be used as a direct replacement for the AT87C52X2-SLSUL?

A: Yes. Both devices share the 80C51 core processor, identical 44-PLCC pinout with 32 I/O pins, and matching voltage specifications (2.7V ~ 5.5V). The substitute is electrically and mechanically compatible for drop-in replacement on existing PCBs.

Q: What are the key differences between these two parts?

A: The primary differences are program memory type (OTP vs. FLASH), program memory size (8KB vs. 16KB), RAM capacity (256 x 8 vs. 1.25K x 8), maximum speed (30/20MHz vs. 60MHz), and product status (obsolete vs. active). The AT89C51RB2-SLSUM provides enhanced functionality while maintaining backward compatibility.

Q: Does the FLASH memory type affect compatibility?

A: No. FLASH memory is a superset of OTP functionality. Firmware designed for OTP execution operates identically on FLASH-based devices. FLASH additionally enables in-system reprogramming, which is not available on OTP parts.

Q: Are there any package or pinout differences?

A: No. Both parts use the 44-PLCC (44-LCC J-Lead) package with identical pinout and 32 I/O pins. No PCB layout modifications are required.

Q: What is the impact of the higher speed specification (60MHz vs. 30/20MHz)?

A: The AT89C51RB2-SLSUM supports higher clock frequencies, enabling faster instruction execution. Existing firmware designed for lower speeds operates correctly at the substitute's rated speed without modification. The higher speed capability does not introduce compatibility issues.

Q: Are both parts RoHS compliant?

A: Yes. Both the AT87C52X2-SLSUL and AT89C51RB2-SLSUM are ROHS3 compliant and REACH unaffected, meeting current environmental and regulatory requirements.

Q: What is the Moisture Sensitivity Level (MSL) difference?

A: The AT87C52X2-SLSUL has MSL 2 (1 Year), while the AT89C51RB2-SLSUM has MSL 3 (168 Hours). This affects storage and handling procedures. Consult component datasheets for specific moisture control requirements during storage and assembly.