AM79C940BJI

Overview

The AM79C940BJI is a Media Access Controller (MACE) designed for Ethernet applications, manufactured by Rochester Electronics. It supports standard Ethernet protocols and interfaces with external physical layer devices. The component is housed in a 100-pin PQFP package. Key electrical specifications include a maximum operating frequency of 25 MHz, ensuring reliable data transmission for networked systems. It operates within a supply voltage range typical for CMOS logic, providing low power consumption suitable for embedded networking solutions.

Feature Summary

• Integrated Media Access Control functionality for Ethernet networks
• Supports standard IEEE 802.3 protocol compliance
• Interfaces directly with external PHY devices via MII or similar standards
• Designed for high reliability in embedded communication systems

Applications

• Embedded Ethernet controllers in industrial automation
• Network interface cards for legacy computing systems
• Communication modules requiring robust MAC layer processing
• IoT gateways and edge devices with wired connectivity needs

Procurement Notes

Verify the specific suffix 'BJI' against official Rochester Electronics documentation to confirm pinout compatibility and temperature grade. Ensure the source provides traceability to original Advanced Micro Devices specifications. Request detailed test reports if used in safety-critical applications. Confirm RoHS status as this part may be lead-free or leaded depending on production batch. Validate package integrity upon receipt.

Selection Notes

Select this component when a dedicated hardware MAC controller is required for Ethernet integration. Compare performance metrics such as throughput and latency against software-based solutions. Consider package availability and footprint constraints during PCB design. Evaluate thermal requirements for the PQFP package in enclosed environments. Verify compatibility with existing system bus architectures before finalizing the selection.

Part Context

This part belongs to the AM79C940 family of Ethernet Media Access Controllers originally developed by Advanced Micro Devices. Rochester Electronics continues production of legacy components through licensing agreements. The AM79C940 series is widely recognized for its role in enabling Ethernet connectivity in various embedded systems. It serves as a bridge between the digital baseband processing and the analog physical layer.

Replacement Considerations

Direct replacements may include other variants within the AM79C940 family, such as AM79C940B, subject to pinout verification. Cross-reference with National Semiconductor DP83815 for integrated MAC/PHY solutions if space reduction is needed. Ensure any substitute maintains compatible voltage levels and interface timing characteristics.