AT87F55WD-24PI Equivalent & Substitute Parts

Part Overview

The AT87F55WD-24PI is an 8051-based 8-bit microcontroller manufactured by Microchip Technology, featuring 20KB OTP Quick FLASH program memory and operating at 24MHz. This device is classified as obsolete, making equivalent and substitute parts necessary for ongoing system support, redesigns, and production continuity. Substitute parts must maintain core 8051 architecture compatibility while meeting the electrical and mechanical requirements of the original application.

Substiute Parts

AT87F55WD-24PI

Microchip TechnologyIn Stock: 880AT87F55WD-24PI Datasheet

Current PartRFQ

DS89C430-MNG+

Analog Devices Inc./Maxim IntegratedIn Stock: 20134DS89C430-MNG+ Datasheet

MFR RecommendedRFQ

DS89C430-MNL+

Analog Devices Inc./Maxim IntegratedIn Stock: 1165DS89C430-MNL+ Datasheet

MFR RecommendedRFQ

DS89C450-MNL+

Analog Devices Inc./Maxim IntegratedIn Stock: 1779DS89C450-MNL+ Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution for the AT87F55WD-24PI is determined by the following critical parameters:

Core Architecture Compatibility: All substitute parts must use the 8051 core processor to ensure instruction set and firmware compatibility.

Package Compatibility: All substitute parts must use 40-DIP through-hole packaging with identical 0.600" (15.24mm) dimensions to ensure PCB footprint compatibility.

Electrical Compatibility: All substitute parts must operate within the 4V to 5.5V supply voltage range and support the -40°C to 85°C operating temperature range.

I/O Count: All substitute parts must provide 32 I/O pins to maintain signal routing compatibility.

Connectivity: All substitute parts must include UART/USART connectivity to support serial communication requirements.

The three substitute parts listed (DS89C430-MNG+, DS89C430-MNL+, and DS89C450-MNL+) meet these core substitution criteria. Differences in program memory size, speed, and memory type represent functional enhancements or variations that may be acceptable depending on application requirements.

Parameter Comparison

Engineering Selection Recommendations

DS89C430-MNG+: This substitute maintains 8051 core compatibility, 40-DIP packaging, and 32 I/O configuration. Operating speed is 25MHz, marginally higher than the original 24MHz. Program memory is reduced to 16KB, which may require code optimization for applications originally designed for 20KB. Product status is obsolete. RoHS3 compliance provides environmental regulatory advantage over the non-compliant original part.

DS89C430-MNL+: This substitute provides identical core architecture, packaging, and I/O configuration to DS89C430-MNG+, with increased operating speed of 33MHz. Program memory remains 16KB. Product status is active, ensuring long-term availability and supply chain stability. RoHS3 compliance is maintained. This part is suitable for applications where the 16KB program memory limitation is acceptable and higher speed operation is beneficial or neutral.

DS89C450-MNL+: This substitute offers the highest program memory capacity at 64KB, accommodating applications with larger code requirements. Operating speed is 33MHz. Product status is active with confirmed availability. RoHS3 compliance is maintained. This part is recommended for applications where the original 20KB memory is insufficient or where future code expansion is anticipated. The 40-DIP package and 32 I/O configuration remain compatible.

Selection between these three substitutes depends on program memory requirements and supply chain priorities. DS89C430-MNL+ and DS89C450-MNL+ are preferred due to active product status.

Frequently Asked Questions (FAQ)

Q: Can DS89C430-MNG+ be used as a direct replacement for AT87F55WD-24PI?

A: DS89C430-MNG+ maintains 8051 core compatibility, identical 40-DIP packaging, 32 I/O pins, and compatible voltage/temperature ranges. The 16KB program memory is smaller than the original 20KB, requiring code review to confirm fit. Operating speed is 25MHz versus 24MHz. Electrical and mechanical compatibility is confirmed.

Q: What is the difference between DS89C430-MNG+ and DS89C430-MNL+?

A: Both parts share identical core architecture, packaging, and memory configuration (16KB FLASH, 1K x 8 RAM). The primary difference is operating speed: DS89C430-MNG+ operates at 25MHz while DS89C430-MNL+ operates at 33MHz. DS89C430-MNL+ has active product status versus obsolete status for DS89C430-MNG+.

Q: Why does DS89C450-MNL+ have 64KB program memory instead of 20KB?

A: DS89C450-MNL+ is a higher-capacity variant within the same 8051 family and 40-DIP package. The increased memory does not affect pin compatibility or electrical characteristics. Applications requiring more than 20KB of program memory can utilize this additional capacity without redesign.

Q: Are all substitute parts RoHS compliant?

A: Yes. DS89C430-MNG+, DS89C430-MNL+, and DS89C450-MNL+ are all ROHS3 compliant. The original AT87F55WD-24PI is RoHS non-compliant. Substitution provides regulatory compliance improvement.

Q: What is the minimum supply voltage for substitute parts?

A: DS89C430-MNG+, DS89C430-MNL+, and DS89C450-MNL+ require 4.5V minimum supply voltage, compared to 4V minimum for the original AT87F55WD-24PI. Applications operating below 4.5V require circuit modification or alternative parts.

Q: Do substitute parts support the same connectivity as the original?

A: All substitute parts include UART/USART connectivity matching the original. Substitute parts additionally support EBI/EMI and SIO connectivity, providing enhanced communication options without removing original functionality.

Q: Which substitute part has the longest supply availability?

A: DS89C430-MNL+ and DS89C450-MNL+ both have active product status, indicating ongoing manufacturing and supply availability. DS89C430-MNG+ is obsolete. For new designs or long-term production, active-status parts are recommended.