AT89C55WD-24JC Equivalent & Substitute Parts

Part Overview

The AT89C55WD-24JC is an 8-bit microcontroller from Microchip Technology's 89C series, featuring 20KB of FLASH program memory, 256 bytes of RAM, and 32 I/O pins. This device operates at 24MHz with a supply voltage range of 4.5V to 5.5V and includes UART/USART connectivity and watchdog timer peripherals. The AT89C55WD-24JC is classified as obsolete, making equivalent substitute parts necessary for ongoing production and maintenance applications. The primary substitute maintains identical core functionality while offering improved product status and compliance certifications.

Substiute Parts

AT89C55WD-24JC

Microchip TechnologyIn Stock: 1499AT89C55WD-24JC Datasheet

Current PartRFQ

AT89C55WD-24JU

Microchip TechnologyIn Stock: 8972AT89C55WD-24JU Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT89C55WD-24JC is based on strict equivalence across all critical electrical and mechanical parameters. The allowed substitute must maintain identical specifications for core processor architecture (8051), core size (8-Bit), operating frequency (24MHz), program memory capacity and type (20KB FLASH), RAM configuration (256 x 8), I/O count (32 pins), supply voltage range (4.5V ~ 5.5V), connectivity interfaces (UART/USART), peripheral features (WDT), and physical packaging (44-LCC J-Lead, 44-PLCC 16.6x16.6mm).

The substitute part AT89C55WD-24JU meets all these criteria. Differences in product status, compliance certifications, and packaging format (tube versus unspecified) do not affect functional or electrical compatibility.

Parameter Comparison

Engineering Selection Recommendations

The AT89C55WD-24JU is the direct functional equivalent of the AT89C55WD-24JC. Both devices are electrically and mechanically identical across all core specifications. Selection between these parts should be based on product availability and compliance requirements.

The AT89C55WD-24JC is classified as obsolete with limited inventory availability (1427 pcs). The AT89C55WD-24JU maintains active product status with significantly higher inventory (8875 pcs), ensuring supply chain continuity. The substitute part carries ROHS3 compliance certification, whereas the main part is RoHS non-compliant. The substitute also provides an extended operating temperature range (-40°C to 85°C versus 0°C to 70°C), offering broader environmental tolerance for industrial applications.

Frequently Asked Questions (FAQ)

Q: Are AT89C55WD-24JC and AT89C55WD-24JU pin-compatible?

A: Yes. Both devices use identical 44-LCC J-Lead packaging with 44-PLCC (16.6x16.6mm) physical dimensions. Pin assignments, electrical characteristics, and functional behavior are identical.

Q: Can AT89C55WD-24JU replace AT89C55WD-24JC in existing designs?

A: Yes. The substitute part maintains identical electrical specifications, memory configuration, I/O count, and peripheral features. No design modifications are required.

Q: What is the difference between the operating temperature ranges?

A: The AT89C55WD-24JC operates from 0°C to 70°C, while the AT89C55WD-24JU operates from -40°C to 85°C. The substitute provides extended temperature coverage suitable for wider environmental conditions.

Q: Why is RoHS compliance different between these parts?

A: The AT89C55WD-24JC predates RoHS3 requirements and is non-compliant. The AT89C55WD-24JU is manufactured to current ROHS3 standards, making it suitable for applications requiring regulatory compliance.

Q: What does the packaging designation "Tube" mean for AT89C55WD-24JU?

A: Tube packaging indicates the parts are supplied in plastic tube containers for automated handling and assembly. This does not affect electrical or mechanical compatibility.

Q: Are there any firmware or software compatibility issues between these parts?

A: No. Both devices implement the identical 8051 core architecture with identical instruction sets, memory organization, and peripheral interfaces. Firmware and software are fully compatible.