LAN91C94TQFP

Application Specific Microcontrollers Overview

The LAN91C94TQFP is a single-chip Ethernet controller integrating ISA and PCMCIA interfaces, manufactured by SMSC. It combines MAC and physical layer functions with 4608 bytes of on-chip RAM to implement high-performance 10BASE-T nodes. The device supports IEEE 802.3 standards and features simultaneous early transmit and receive capabilities. It utilizes a flat memory structure for low CPU overhead and includes a hardware memory management unit. The component operates on a single +5V supply and is housed in a 100-pin TQFP package.

Application Specific Microcontrollers Feature Summary

• Integrates ISA and PCMCIA interfaces with 4608 bytes of on-chip packet RAM
• Supports 10BASE-T twisted pair implementations directly; interfaces to external transceivers for 10BASE5, 10BASE2, and 10BASE-F via AUI port
• Features Simultasking™ Early Transmit and Early Receive functions for enhanced performance
• Includes hardware Memory Management Unit (MMU) and dynamic memory allocation between transmit and receive buffers

Application Specific Microcontrollers Applications

• ISA bus expansion cards for desktop computers
• PCMCIA network interface cards for portable systems
• Diskless workstation boot applications requiring Boot PROM support

Application Specific Microcontrollers Procurement Notes

Verify the specific suffix 'TQFP' confirms the 100-pin thin quad flat package variant. Confirm the manufacturer origin as SMSC or its successors, as product lines may have been transferred. Ensure the component meets the required single +5V power supply specification and check for lead-free compliance if necessary for modern assembly processes.

Application Specific Microcontrollers Selection Notes

Select this controller when both ISA and PCMCIA compatibility are required within a single chip solution. It is suitable for designs needing integrated 10BASE-T transceiver functions without external PHY components for standard twisted-pair connections. Consider the 4KB internal RAM limit for buffer requirements compared to higher-capacity controllers like the LAN91C111.

Application Specific Microcontrollers Part Context

The LAN91C94 belongs to the SMSC 91C series of Ethernet controllers, designed primarily for legacy PC architectures. It serves as a pin-compatible alternative to the LAN91C92 in ISA mode while adding PCMCIA support. This integration reduces board space and component count for embedded networking solutions requiring dual-interface flexibility.

Application Specific Microcontrollers Replacement Considerations

The LAN91C92 is noted as pin-compatible in ISA mode but lacks PCMCIA functionality. For upgrades requiring higher speeds or PCI interfaces, the LAN91C111 offers 10/100 Mbps capability but requires different interface logic.