AT90S4433-8PI Equivalent & Substitute Parts

Part Overview

The AT90S4433-8PI is an 8-bit AVR microcontroller manufactured by Microchip Technology, featuring 4KB of FLASH program memory and operating at 8MHz. This device is classified as obsolete, which necessitates identification of functionally compatible alternatives for new designs and production continuity. The part is housed in a 28-DIP package with through-hole mounting and supports SPI and UART/USART connectivity interfaces.

Substiute Parts

AT90S4433-8PI

Microchip TechnologyIn Stock: 1332AT90S4433-8PI Datasheet

Current PartRFQ

ATMEGA8L-8PU

Microchip TechnologyIn Stock: 6587ATMEGA8L-8PU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT90S4433-8PI is determined by the following critical parameters:

• Core Architecture: AVR processor family compatibility
• Package Type: 28-DIP through-hole form factor
• Operating Voltage Range: Supply voltage compatibility
• Memory Configuration: Program memory, EEPROM, and RAM capacity
• Connectivity Interfaces: SPI and UART/USART support
• Peripheral Features: Brown-out detect/reset, POR, PWM, and WDT functionality
• Operating Temperature Range: -40°C to 85°C specification

The ATMEGA8L-8PU qualifies as a substitute based on matching core architecture, package type, operating temperature range, and peripheral feature set. The substitute part maintains compatibility with the same 28-DIP package and supports the required connectivity interfaces.

Parameter Comparison

Engineering Selection Recommendations

The ATMEGA8L-8PU is the qualified substitute for the AT90S4433-8PI based on the following engineering criteria:

Product Status: The AT90S4433-8PI is obsolete, while the ATMEGA8L-8PU is in active production, ensuring long-term availability and supply chain continuity.

Compliance: The ATMEGA8L-8PU is ROHS3 compliant, meeting current regulatory requirements, whereas the AT90S4433-8PI is RoHS non-compliant.

Package Compatibility: Both devices utilize the identical 28-DIP (0.300", 7.62mm) through-hole package, enabling direct board-level substitution without layout modifications.

Electrical Compatibility: The substitute part maintains the same 8-bit AVR core architecture, 8MHz operating speed, and identical peripheral feature set (Brown-out Detect/Reset, POR, PWM, WDT). The ATMEGA8L-8PU supports a wider supply voltage range (2.7V ~ 5.5V) compared to the original part (4V ~ 6V), providing enhanced flexibility for power supply design.

Memory Enhancement: The ATMEGA8L-8PU provides doubled program memory (8KB versus 4KB), doubled EEPROM (512 x 8 versus 256 x 8), and increased RAM (1K x 8 versus 128 x 8), offering improved capability for complex applications without architectural changes.

Interface Expansion: The substitute includes I2C connectivity in addition to the SPI and UART/USART interfaces present in the original part, and provides three additional I/O pins (23 versus 20).

Frequently Asked Questions (FAQ)

Q: Can the ATMEGA8L-8PU be used as a direct replacement for the AT90S4433-8PI?

A: Yes, the ATMEGA8L-8PU is a direct substitute. Both devices share the same 28-DIP package, identical core architecture, operating speed, and peripheral feature set. No board layout modifications are required for physical substitution.

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

A: The primary differences are: (1) Product status—the AT90S4433-8PI is obsolete while the ATMEGA8L-8PU is active; (2) Memory capacity—the substitute offers doubled program memory, EEPROM, and RAM; (3) Supply voltage range—the substitute supports 2.7V to 5.5V versus 4V to 6V; (4) I/O count—the substitute provides 23 pins versus 20; (5) Connectivity—the substitute includes I2C in addition to SPI and UART/USART; (6) Compliance—the substitute is ROHS3 compliant.

Q: Are there any software compatibility concerns when switching from AT90S4433-8PI to ATMEGA8L-8PU?

A: Both devices use the same AVR instruction set architecture. Existing firmware compiled for the AT90S4433-8PI will execute on the ATMEGA8L-8PU. However, applications must account for the different memory map and peripheral register addresses specific to each device variant.

Q: Does the wider voltage range of the ATMEGA8L-8PU affect circuit design?

A: The ATMEGA8L-8PU supports operation from 2.7V to 5.5V, which encompasses the original part's 4V to 6V range. Existing power supply designs for the AT90S4433-8PI remain compatible. The wider range provides additional flexibility for low-power applications.

Q: What is the significance of the additional I/O pins on the ATMEGA8L-8PU?

A: The ATMEGA8L-8PU provides 23 I/O pins compared to 20 on the AT90S4433-8PI. These additional pins are available within the same 28-DIP package footprint and can be utilized for expanded application functionality without requiring board redesign.

Q: Is the ATMEGA8L-8PU available in the same packaging format?

A: Yes, both devices are available in the 28-DIP (0.300", 7.62mm) through-hole package. Pin-to-pin physical compatibility is maintained, allowing direct socket substitution.