NXP Semiconductors SC16C550BIB48,157

Overview

SC16C550BIB48 from NXP Semiconductors is a 5 V / 3.3 V / 2.5 V universal asynchronous receiver/transmitter (UART) with 16-byte transmit and receive FIFOs, supporting up to 3 Mbit/s at 5 V, 2 Mbit/s at 3.3 V, and 1 Mbit/s at 2.5 V. It implements full modem control (CTS/RTS/DSR/DTR/RI/DCD), auto-RTS/CTS hardware flow control, and programmable baud rate generation for industrial serial communication interfaces.

For engineers reviewing the SC16C550BIB48 datasheet, SC16C550BIB48 pinout, SC16C550BIB48 application, or SC16C550BIB48 equivalent, key selection considerations include LQFP48 package compatibility, FIFO trigger level configuration (1/4/8/14 bytes), DMA-ready RXRDY/TXRDY signaling, 3-state TTL bus interface, and industrial temperature range (−40 °C to +85 °C) operation.

Technical Context

The SC16C550BIB48 integrates a 16× baud-rate clock generator with programmable divisor latches (DLL/DLM), enabling precise baud rates up to 3 Mbit/s using a 48 MHz input clock. Its dual 16-byte FIFO architecture decouples CPU servicing from serial data timing, reducing interrupt overhead in multi-channel embedded systems.

It supports register-level compatibility with the legacy 16C450 upon reset and maintains pin compatibility with ST16C550, TL16C550, and PC16C550 families. The LQFP48 package provides full access to all control signals-including AS, CS0–CS2, IOR/IOW variants, and RCLK-enabling direct integration into 8-bit parallel bus microcontroller systems.

Key Specifications

Pinout & Package

LQFP48 package (SOT313-2), 7 mm × 7 mm × 1.4 mm body, 0.5 mm lead pitch, exposed thermal pad (VSS-connected). All 48 pins are electrically defined per NXP datasheet Rev. 6.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar UART applications.

Compared with TL16C550CPM and ST16C550CQ48, the SC16C550BIB48 uniquely delivers triple-voltage operation (2.5/3.3/5 V), industrial temperature rating, and full LQFP48 signal access - making it the only option for new designs requiring voltage scalability and extended environmental qualification.

Availability

SC16C550BIB48 is available at Aetrix Electronics and suitable for industrial PLC gateways, medical device interfaces, POS terminal hubs, and network equipment console ports requiring stable component supply across long production lifecycles.

Supply support for SC16C550BIB48 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

NXP Semiconductors is a global semiconductor leader specializing in secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in interface ICs and embedded processing.

The SC16C550BIB48 belongs to NXP's legacy industrial UART product line, designed specifically for robust, drop-in replacement of 16C450/550-family devices in mission-critical serial communication subsystems.

FAQ

What voltage levels does the SC16C550BIB48 support, and how does that affect system design?

The SC16C550BIB48 operates at 2.5 V, 3.3 V, or 5 V ±10 %, allowing direct integration into mixed-voltage embedded systems without external level-shifting circuitry. This simplifies power domain partitioning and reduces BOM count in industrial controllers where legacy 5 V peripherals coexist with modern 3.3 V or ultra-low-power 2.5 V MCUs. All I/O pins are 5 V tolerant on inputs only - critical for interfacing with higher-voltage transceivers while maintaining safe logic-level signaling.

Does the SC16C550BIB48 support hardware flow control, and how is it implemented?

Yes, the SC16C550BIB48 supports full hardware flow control via programmable auto-RTS and auto-CTS modes. Auto-RTS asserts/de-asserts the RTS output based on RX FIFO fill level (configurable at 1/4/8/14 bytes), while auto-CTS gates the transmitter using the CTS input signal. These functions are enabled via MCR[5] and MCR[1] bits and eliminate software-managed handshaking - reducing CPU overhead and preventing data loss during high-throughput transfers in SC16C550BIB48-based systems.

What is the maximum serial data rate achievable with the SC16C550BIB48, and what clock frequency is required?

The SC16C550BIB48 supports up to 3 Mbit/s at 5 V, 2 Mbit/s at 3.3 V, and 1 Mbit/s at 2.5 V. To achieve 3 Mbit/s, a 48 MHz clock must be applied to XTAL1 (or generated internally via crystal across XTAL1/XTAL2). The internal baud rate generator divides this 16× clock by a programmable divisor (1–65535) to produce the final serial rate; BAUDOUT outputs the exact 16× baud clock for synchronization of external receivers or transceivers in SC16C550BIB48 designs.

How does the SC16C550BIB48 handle interrupt prioritization and multiple pending conditions?

The SC16C550BIB48 uses a fixed-priority interrupt scheme where Receive Data Ready and Receive Time-Out share the highest priority, followed by Transmit Holding Register Empty, then Modem Status Change. The Interrupt Status Register (ISR) reports only the highest-pending condition; lower-priority interrupts become visible only after servicing the current one. This ensures deterministic response to time-critical events like FIFO overflow or line errors - essential for real-time SC16C550BIB48 implementations in industrial control loops.

Is the SC16C550BIB48 pin-compatible with older 16C450/550 UARTs, and what initialization behavior occurs after reset?

Yes, the SC16C550BIB48 is pin-compatible with ST16C550, TL16C550, and PC16C550 devices and powers up functionally equivalent to the 16C450 - meaning all registers match the 16C450 map upon reset and it runs with existing 16C450 software without modification. This enables seamless drop-in upgrades in legacy systems, preserving firmware investment while gaining 16-byte FIFOs, auto-flow control, and triple-voltage operation in the SC16C550BIB48.