11C91DMQB

Overview

The National Semiconductor 11C91DMQB is a high-speed prescaler designed for ECL logic families. It operates as a divide-by-2 or divide-by-4 circuit, supporting input frequencies up to 650 MHz. The device is housed in a 16-lead ceramic dual in-line package (CDIP16). It functions as a general-purpose RF component suitable for frequency division applications requiring high-frequency performance and ECL compatibility.

Feature Summary

• Supports ECL logic family operation
• Capable of divide-by-2 and divide-by-4 frequency division
• Operates at input frequencies up to 650 MHz

Applications

• RF signal processing systems
• Frequency synthesis circuits
• High-speed clock distribution networks

Procurement Notes

Verify the specific suffix 'DMQB' against the manufacturer's official datasheet to confirm pinout and electrical characteristics. Ensure the CDIP16 package type matches the design requirements. Confirm that the ECL voltage levels are compatible with the system power supply. Check for active status or obsolescence notices from National Semiconductor or Texas Instruments before procurement.

Selection Notes

Select this component when a high-frequency prescaler operating above 650 MHz is required within an ECL-based architecture. The CDIP16 package is suitable for applications requiring robust thermal dissipation and reliable mounting in industrial environments. Consider the divide-by-2 and divide-by-4 functionality for flexible frequency scaling needs in RF front-end designs.

Part Context

The 11C91 series consists of high-speed prescalers manufactured by National Semiconductor, now part of Texas Instruments. These devices are engineered for demanding RF and microwave applications where precise frequency division is critical. The 11C91DMQB variant specifically utilizes the ECL logic standard, offering fast switching speeds and low noise performance compared to other logic families.

Replacement Considerations

Equivalent parts include the 11C91DCQB and 11C91DMQC from National Semiconductor/Fairchild. Verify pin compatibility and electrical specifications before substitution. Consult the official replacement guide for cross-reference accuracy.