AT90S8535-8AC Equivalent & Substitute Parts

Part Overview

The AT90S8535-8AC is an 8-bit AVR microcontroller manufactured by Microchip Technology, featuring 8KB FLASH program memory, 512 bytes EEPROM, and 32 I/O pins in a 44-TQFP package. This device is classified as obsolete and has been superseded by newer AVR microcontroller variants. Finding equivalent substitute parts is necessary due to the discontinued status of this component, which impacts long-term availability and supply chain reliability for new designs and production runs.

Substiute Parts

AT90S8535-8AC

Microchip TechnologyIn Stock: 1726AT90S8535-8AC Datasheet

Current PartRFQ

ATMEGA8535L-8AU

Microchip TechnologyIn Stock: 7750ATMEGA8535L-8AU Datasheet

MFR RecommendedRFQ

Key Parameters

Substitute Part Grouping Explanation

Substitution of the AT90S8535-8AC is determined by the following critical parameters:

Core Architecture & Memory Configuration: The substitute must maintain the AVR core processor architecture with identical program memory size (8KB FLASH), EEPROM capacity (512 x 8), and RAM size (512 x 8) to ensure firmware compatibility without modification.

Electrical Specifications: The substitute must support the same operating frequency (8MHz) and maintain compatible I/O pin count (32 pins) with identical peripheral functionality including SPI, UART/USART, PWM, WDT, and Brown-out Detect/Reset capabilities.

Package & Physical Compatibility: The substitute must use the 44-TQFP (10x10) surface mount package to ensure PCB layout compatibility and mechanical fit without redesign.

Voltage Supply Range: While the original part operates at 4V ~ 6V, substitute parts with extended voltage ranges (such as 2.7V ~ 5.5V) remain compatible as they encompass the original operating window.

The ATMEGA8535L-8AU meets all substitution criteria through identical core architecture, memory configuration, I/O count, package format, and peripheral set.

Parameter Comparison

Engineering Selection Recommendations

The ATMEGA8535L-8AU is the direct functional equivalent and recommended substitute for the obsolete AT90S8535-8AC. Selection is based on the following engineering criteria:

Product Status & Availability: The AT90S8535-8AC is classified as obsolete, creating supply chain risk. The ATMEGA8535L-8AU maintains active product status with verified availability, ensuring long-term procurement reliability.

Regulatory Compliance: The ATMEGA8535L-8AU is ROHS3 compliant, meeting current environmental and regulatory requirements. The original AT90S8535-8AC is RoHS non-compliant, making the substitute preferable for new designs and production environments subject to compliance mandates.

Functional Equivalence: Both devices share identical core architecture, memory configuration, I/O count, package format, and peripheral set. The ATMEGA8535L-8AU includes additional I2C connectivity as a superset feature, providing enhanced functionality without compromising backward compatibility.

Electrical Compatibility: The ATMEGA8535L-8AU operates within an extended voltage supply range (2.7V ~ 5.5V) that encompasses the original device's operating window (4V ~ 6V), ensuring compatibility across existing power supply designs. Extended operating temperature range (-40°C ~ 85°C) provides additional environmental margin compared to the original specification (0°C ~ 70°C).

Frequently Asked Questions (FAQ)

Q: Can the ATMEGA8535L-8AU be used as a direct replacement for the AT90S8535-8AC without firmware modification?

A: Yes. Both devices share identical AVR core architecture, program memory size (8KB FLASH), EEPROM capacity (512 x 8), RAM size (512 x 8), I/O pin count (32), and peripheral functionality. Existing firmware compiled for the AT90S8535-8AC will execute without modification on the ATMEGA8535L-8AU.

Q: Are there any package or pinout differences between these devices?

A: No. Both devices use the 44-TQFP (10x10) surface mount package with identical pinout. PCB layouts designed for the AT90S8535-8AC require no modification to accommodate the ATMEGA8535L-8AU.

Q: What is the significance of the extended voltage supply range in the ATMEGA8535L-8AU?

A: The ATMEGA8535L-8AU operates across 2.7V ~ 5.5V, which fully encompasses the original device's 4V ~ 6V range. This extended specification provides design flexibility and compatibility with a broader range of power supply configurations without compromising the original operating window.

Q: Does the ATMEGA8535L-8AU include additional features compared to the AT90S8535-8AC?

A: The ATMEGA8535L-8AU includes I2C connectivity in addition to the SPI and UART/USART interfaces present in the original device. This represents a functional superset that maintains full backward compatibility while providing enhanced communication options.

Q: What is the impact of the extended operating temperature range?

A: The ATMEGA8535L-8AU operates across -40°C ~ 85°C compared to the original 0°C ~ 70°C specification. This extended range provides additional environmental margin and compatibility with applications requiring operation in wider temperature extremes.

Q: Why is RoHS3 compliance important for the substitute part?

A: RoHS3 compliance ensures the ATMEGA8535L-8AU meets current environmental and regulatory requirements for electronic components. The original AT90S8535-8AC is RoHS non-compliant, making the substitute mandatory for new designs and production environments subject to RoHS directives.

Q: Is the ATMEGA8535L-8AU available in the same packaging format?

A: Yes. The ATMEGA8535L-8AU is supplied in 44-TQFP (10x10) surface mount packaging, identical to the original device. No PCB redesign or assembly process modification is required.