SCC2681AC1A44,529

UARTs (Universal Asynchronous Receiver Transmitter) Overview

The NXP SCC2681AC1A44,529 is a Dual Universal Asynchronous Receiver/Transmitter (DUART) manufactured in a CMOS process. It provides two independent full-duplex asynchronous channels within a single package, interfacing directly with microprocessors via an 8-bit bidirectional data bus. The device supports programmable data formats including 5 to 8 data bits plus parity and 1, 1.5, or 2 stop bits. Each channel features quadruple buffered receiver data registers and selectable baud rates ranging from 50 to 115.2 kbps using fixed rates, a 16x clock derived from a programmable counter/timer, or external clocks. It operates on a single +5 V supply and includes a multipurpose 7-bit input port and an 8-bit output port for general I/O or specific control functions.

UARTs (Universal Asynchronous Receiver Transmitter) Feature Summary

• Dual full-duplex asynchronous receiver/transmitter channels with independent programming capabilities
• Quadruple buffered receiver data registers to minimize overrun potential and reduce interrupt overhead
• Programmable baud rate generator supporting fixed rates up to 115.2 kbps and user-defined rates via a 16-bit counter/timer
• Integrated multipurpose 7-bit input port with change-of-state detection and 8-bit output port with individual bit set/reset

UARTs (Universal Asynchronous Receiver Transmitter) Applications

• Clustered terminal systems requiring dual-speed channel applications
• Polled or interrupt-driven microprocessor communication systems
• Multidrop applications utilizing automatic wake-up mode

UARTs (Universal Asynchronous Receiver Transmitter) Procurement Notes

Verify the exact ordering suffix against the manufacturer's current documentation to confirm package type and temperature range. The part number indicates a PLCC44 package with commercial temperature specifications. Confirm availability status as legacy components may have limited distribution channels. Ensure compatibility with existing system voltage levels and interface requirements before procurement.

UARTs (Universal Asynchronous Receiver Transmitter) Selection Notes

Select this component when dual independent asynchronous channels are required within a single integrated circuit. Consider the PLCC44 package if surface mount assembly is preferred over DIP variants. Verify that the required baud rates align with the available fixed options or can be generated by the internal counter/timer. Ensure the system design accommodates the +5 V power supply requirement and utilizes the available I/O ports effectively.

UARTs (Universal Asynchronous Receiver Transmitter) Part Context

The SCC2681 series belongs to the Philips/NXP Semiconductors DUART family, serving as a direct replacement for older NMOS-based devices like the SCN2681. This CMOS version offers lower power consumption while maintaining functional compatibility. The AC1A44 variant specifically denotes the commercial temperature grade housed in a 44-lead plastic leaded chip carrier package, distinguishing it from industrial grade or DIP package alternatives.

UARTs (Universal Asynchronous Receiver Transmitter) Replacement Considerations

SCC2681AE1A44 serves as the industrial temperature grade equivalent in the same PLCC44 package. For DIP packages, SCC2681AC1N40 (DIP40) and SCC2681AC1N28 (DIP28) are available alternatives. Direct pin-compatible replacements should be verified against the latest datasheet revisions to ensure electrical parameter alignment.