PIC17LC44-08I/PQ Equivalent & Substitute Parts

Part Overview

The PIC17LC44-08I/PQ is an 8-bit microcontroller from Microchip Technology's PIC® 17C series, featuring 16KB OTP program memory and operating at 8MHz. This device is classified as Active product status and remains in production. Substitute parts are identified when original inventory becomes unavailable, when design requirements shift toward enhanced capabilities, or when supply chain constraints necessitate alternative sourcing while maintaining functional compatibility within the 44-pin MQFP/TQFP package class.

Substiute Parts

PIC17LC44-08I/PQ

Microchip TechnologyIn Stock: 1912PIC17LC44-08I/PQ Datasheet

Current PartRFQ

PIC18F4420-I/PT

Microchip TechnologyIn Stock: 2752PIC18F4420-I/PT Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the PIC17LC44-08I/PQ is evaluated based on the following critical parameters:

• Core Processor Family: Both main and substitute parts must be PIC architecture from Microchip Technology
• Core Size: 8-bit processing capability required
• Program Memory Size: 16KB (8K x 16) minimum capacity
• Package Class: 44-pin surface mount packages (MQFP or TQFP variants)
• Operating Temperature Range: -40°C ~ 85°C compatibility
• Compliance: ROHS3 compliance maintained

The PIC18F4420-I/PT qualifies as a direct substitute based on these parameters. While it introduces enhanced specifications (FLASH memory instead of OTP, higher speed, expanded I/O), it maintains the core functional envelope and package compatibility required for drop-in replacement scenarios.

Parameter Comparison

Engineering Selection Recommendations

PIC18F4420-I/PT as Primary Substitute

The PIC18F4420-I/PT is qualified as a substitute based on:

• Active product status with verified availability (2700 pcs in stock)
• ROHS3 compliance maintained across both parts
• Identical operating temperature range (-40°C ~ 85°C)
• Matching MSL rating (3, 168 Hours)
• Compatible 44-pin surface mount package footprint
• Identical program memory capacity (16KB)

Design considerations when implementing this substitute:

• Voltage supply range narrows from 2.5V ~ 6V to 4.2V ~ 5.5V; verify power supply specifications
• FLASH memory replaces OTP; firmware update capability is now available
• Processing speed increases from 8MHz to 40MHz; timing-dependent code may require validation
• RAM expands from 454 x 8 to 768 x 8; additional buffer capacity available
• I/O count increases from 33 to 36; additional pins available for expansion

Frequently Asked Questions (FAQ)

Q: Can the PIC18F4420-I/PT directly replace the PIC17LC44-08I/PQ without PCB modifications?

A: The 44-pin MQFP and 44-TQFP packages share identical pin counts and footprints. PCB layout compatibility is maintained. However, verify that your power supply meets the narrower 4.2V ~ 5.5V range of the substitute part.

Q: What is the primary difference between OTP and FLASH memory in these parts?

A: The PIC17LC44-08I/PQ uses OTP (One-Time Programmable) memory, which cannot be erased after programming. The PIC18F4420-I/PT uses FLASH memory, which supports multiple erase/program cycles. This enables in-system firmware updates on the substitute part.

Q: Are there connectivity differences between these microcontrollers?

A: The PIC17LC44-08I/PQ provides UART/USART connectivity. The PIC18F4420-I/PT expands this with I2C and SPI interfaces, offering greater communication protocol flexibility.

Q: Does the speed increase from 8MHz to 40MHz require firmware changes?

A: Firmware will execute faster on the PIC18F4420-I/PT. Timing-dependent code sections (delays, PWM frequencies, serial communication baud rates) must be validated and adjusted if necessary to maintain intended system behavior.

Q: Are both parts RoHS compliant?

A: Yes. Both the PIC17LC44-08I/PQ and PIC18F4420-I/PT are ROHS3 compliant and maintain identical MSL ratings (3, 168 Hours).