PIC18LF4439-I/PT Equivalent & Substitute Parts

Part Overview

The PIC18LF4439-I/PT is an 8-bit microcontroller from Microchip Technology's PIC® 18F series, featuring 12KB FLASH program memory, 640 bytes of RAM, and 256 bytes of EEPROM. This device operates at 40MHz with a supply voltage range of 2V to 5.5V and is housed in a 44-TQFP surface mount package. The part is currently classified as obsolete, making identification of functionally equivalent alternatives essential for ongoing design support and production continuity.

Substiute Parts

PIC18LF4439-I/PT

Microchip TechnologyIn Stock: 1016PIC18LF4439-I/PT Datasheet

Current PartRFQ

PIC18LF4431-I/PT

Microchip TechnologyIn Stock: 1031PIC18LF4431-I/PT Datasheet

DirectRFQ

Key Parameters

Substitute Part Grouping Explanation

The PIC18LF4431-I/PT qualifies as a direct substitute based on the following alignment of critical parameters:

Matching Parameters:

• Identical manufacturer (Microchip Technology)
• Identical core processor architecture (PIC)
• Identical core size (8-Bit)
• Identical operating speed (40MHz)
• Identical package format (44-TQFP, 10x10)
• Identical supply voltage range (2V ~ 5.5V)
• Identical operating temperature range (-40°C ~ 85°C)
• Identical connectivity interfaces (I2C, SPI, UART/USART)
• Identical EEPROM capacity (256 x 8)
• Identical RoHS compliance status (ROHS3 Compliant)

Enhanced Specifications: The PIC18LF4431-I/PT provides increased program memory (16KB versus 12KB), expanded RAM (768 x 8 versus 640 x 8), additional I/O pins (36 versus 32), enhanced analog-to-digital conversion (9x10b versus 8x10b), and additional peripheral support (QEI, Power Control PWM). The substitute maintains active product status, ensuring continued availability and support.

Parameter Comparison

Engineering Selection Recommendations

The PIC18LF4431-I/PT is the appropriate substitute for the obsolete PIC18LF4439-I/PT based on the following engineering criteria:

Compliance & Certification: Both devices maintain ROHS3 compliance and identical moisture sensitivity ratings (MSL 3, 168 hours), ensuring equivalent environmental and regulatory standing.

Product Lifecycle: The PIC18LF4431-I/PT holds active product status with verified programmability through DiGi-Electronics, providing assured long-term availability and technical support. The PIC18LF4439-I/PT's obsolete classification necessitates transition to an actively supported alternative.

Electrical & Mechanical Compatibility: Identical package format (44-TQFP, 10x10), supply voltage range (2V ~ 5.5V), operating temperature range (-40°C ~ 85°C), and core architecture ensure direct functional compatibility in existing PCB layouts and firmware implementations.

Enhanced Capability: The substitute provides increased program memory, expanded RAM, and additional I/O capacity without introducing incompatibility, supporting design scalability and future feature expansion.

Frequently Asked Questions (FAQ)

Q: Can the PIC18LF4431-I/PT be used as a direct replacement for the PIC18LF4439-I/PT in existing designs?

A: Yes. Both devices share identical package format (44-TQFP), pinout compatibility within the 32 I/O pins of the original design, supply voltage range (2V ~ 5.5V), operating temperature range (-40°C ~ 85°C), and core processor architecture. Existing firmware requires no modification for basic functionality. The additional I/O pins (36 versus 32) and enhanced memory on the substitute do not create incompatibility.

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

A: The PIC18LF4431-I/PT provides 16KB program memory compared to 12KB on the PIC18LF4439-I/PT, 768 bytes of RAM versus 640 bytes, 36 I/O pins versus 32, and 9-channel analog-to-digital conversion versus 8-channel. Both operate at 40MHz with identical supply voltage and temperature specifications.

Q: Is the PIC18LF4431-I/PT available in the same package as the original part?

A: Yes. Both devices are supplied in 44-TQFP (10x10) surface mount packages with identical physical dimensions and pin spacing, enabling direct PCB compatibility without layout modifications.

Q: What is the product status difference, and why does it matter?

A: The PIC18LF4439-I/PT is classified as obsolete, indicating discontinued manufacturing and limited availability. The PIC18LF4431-I/PT maintains active product status with ongoing production and technical support from Microchip Technology, ensuring supply chain reliability and access to technical documentation.

Q: Are there any compliance or certification differences between these parts?

A: No. Both devices maintain identical ROHS3 compliance status, moisture sensitivity level (MSL 3, 168 hours), and regulatory certifications (REACH Unaffected, ECCN 3A991A2, HTSUS 8542.31.0001).

Q: Can firmware developed for the PIC18LF4439-I/PT run on the PIC18LF4431-I/PT without modification?

A: Yes. The identical core processor architecture, instruction set, and peripheral interfaces (I2C, SPI, UART/USART) ensure firmware compatibility. The increased memory resources on the substitute do not require code changes for existing applications.