SC28L91A1B,551

UARTs (Universal Asynchronous Receiver Transmitter) Overview

The SC28L91A1B,551 is a single-channel Universal Asynchronous Receiver/Transmitter (UART) from the IMPACT family, manufactured by NXP Semiconductors. It operates on a single +3.3 V or +5 V power supply and supports data rates up to 1 Mbit/s. The device features 16-byte receive and transmit FIFOs to minimize overrun and underrun errors. It includes a programmable baud rate generator, a 16-bit counter/timer, and an on-chip crystal oscillator. The UART provides full-duplex asynchronous communication with configurable data formats, parity, and stop bits. It offers versatile interrupt capabilities and general-purpose I/O ports for system integration.

UARTs (Universal Asynchronous Receiver Transmitter) Feature Summary

• Supports both Intel (80xxx) and Motorola (68K) bus interfaces via pin programming.
• Includes 16-character FIFOs for both receiver and transmitter to reduce CPU overhead.
• Features a programmable baud rate generator supporting fixed rates up to 230.4 kbaud and user-defined rates up to 1 Mbit/s.
• Integrates a watchdog timer for the receiver and change-of-state detectors for input pins.

UARTs (Universal Asynchronous Receiver Transmitter) Applications

• Clustered terminal systems requiring dual-speed channel applications.
• Multi-drop serial communication networks utilizing automatic wake-up modes.
• Microprocessor-based embedded systems requiring polled or interrupt-driven serial interfaces.

UARTs (Universal Asynchronous Receiver Transmitter) Procurement Notes

Verify the specific ordering suffix against the manufacturer's current documentation to confirm package type and temperature range. Ensure compatibility with the target system's voltage levels and bus interface requirements before procurement. Cross-reference the part number with official NXP distributors to confirm availability and authenticity.

UARTs (Universal Asynchronous Receiver Transmitter) Selection Notes

Select this component when a single-channel UART with high-speed capabilities and FIFO buffering is required. It is suitable for designs needing flexible bus interface options between Intel and Motorola architectures. Consider the PQFP-44 package constraints and ensure adequate thermal management for the specified operating temperature range.

UARTs (Universal Asynchronous Receiver Transmitter) Part Context

The SC28L91 belongs to the IMPACT family of Serial Communications Controllers. It serves as an evolution of previous single-channel UARTs like the SCC2691, offering improved performance through larger FIFOs, extended baud rate capabilities, and enhanced interrupt structures while maintaining software compatibility with earlier Philips UARTs.

UARTs (Universal Asynchronous Receiver Transmitter) Replacement Considerations

The SCC2691 is explicitly noted as not being discontinued and remains a compatible alternative. Designers should verify register-level compatibility if migrating between these parts within the IMPACT family.