NXP Semiconductors SC16C550BIB48,151

Overview

SC16C550BIB48 from NXP Semiconductors is a 48-pin LQFP UART IC that converts parallel data to serial and vice versa for industrial embedded communication systems, supporting up to 3 Mbit/s at 5 V, 2 Mbit/s at 3.3 V, and 1 Mbit/s at 2.5 V, with 16-byte transmit and receive FIFOs, programmable baud rate generation, and full modem control (CTS/RTS/RI/DCD/DSR/DTR).

For engineers reviewing the SC16C550BIB48 datasheet, SC16C550BIB48 pinout, SC16C550BIB48 application, or SC16C550BIB48 equivalent, this page delivers verified electrical specs, LQFP48 package mapping, FIFO-triggered interrupt behavior, auto-RTS/CTS flow control implementation, and validated alternative parts for legacy 16C550-based designs requiring stable supply and industrial temperature operation (−40 °C to +85 °C).

Technical Context

The SC16C550BIB48 implements a dual-FIFO asynchronous serial interface with independent transmitter and receiver clock domains, using a 16× oversampling architecture for reliable start/stop bit detection and parity checking. Its register set is fully backward-compatible with the 16C450 after reset, enabling drop-in software reuse.

Hardware flow control is implemented via dedicated RTS/CTS pins with four programmable receive FIFO trigger levels (1/4/8/14 bytes), while DMA signaling (RXRDY/TXRDY) operates in two modes-single-transfer and multi-transfer-controlled by FCR[3] and FCR[0]. BAUDOUT provides a 16× baud-rate clock output usable as RCLK when externally wired.

Key Specifications

Pinout & Package

LQFP48 package (7 mm × 7 mm × 1.4 mm body, SOT313-2), thermally enhanced for industrial PCB layouts with exposed pad grounding recommended per NXP layout guidelines.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL16C550CPTR and ST16C550CQ48, the SC16C550BIB48 uniquely integrates DDIS for transceiver enable control and BAUDOUT for clock fanout - critical for compact RS-485 gateways and multi-peripheral timing synchronization where board space and signal routing are constrained.

Availability

SC16C550BIB48 is available at Aetrix Electronics and suitable for industrial PLC gateways, legacy PC retrofits, telecom line card management, and medical device serial interfaces requiring stable component supply across extended product 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 focused on secure connectivity solutions for automotive, industrial, and IoT applications, with deep expertise in interface, power, and security ICs.

The SC16C550BIB48 belongs to NXP's legacy industrial UART product line, designed specifically for robust, long-lifecycle serial communication in mission-critical embedded systems operating across −40 °C to +85 °C.

FAQ

What voltage levels does the SC16C550BIB48 support, and how does it handle mixed-voltage interfacing?

The SC16C550BIB48 operates at 2.5 V, 3.3 V, or 5 V ±10 % supply, and its D0–D7, A0–A2, CS0–CS2, IOR/IOW, RESET, AS, and modem input pins are 5 V tolerant - meaning they accept 5 V logic signals even when VDD is 2.5 V or 3.3 V. This eliminates external level shifters in mixed-voltage designs, simplifying integration with legacy 5 V controllers or modern low-voltage SoCs. The SC16C550BIB48 maintains full register compatibility and timing across all three supply voltages.

Does the SC16C550BIB48 support hardware flow control, and how is auto-RTS configured?

Yes, the SC16C550BIB48 supports full hardware flow control via RTS and CTS pins. Auto-RTS is enabled by setting MCR[5] and MCR[1], causing RTS to de-assert when the RX FIFO reaches one of four user-programmable trigger levels (1, 4, 8, or 14 bytes). RTS reasserts automatically once space becomes available. This prevents RX FIFO overrun without CPU intervention - a key advantage over basic UARTs. The SC16C550BIB48 implements this logic entirely in hardware, independent of host software polling.

How does the SC16C550BIB48 differ from the original 16C450, and what software changes are needed?

The SC16C550BIB48 is functionally identical to the 16C450 after reset - all registers match, and existing 16C450 drivers execute without modification. Key enhancements include 16-byte TX/RX FIFOs (vs. none), four FIFO interrupt trigger levels, auto-RTS/CTS, and DMA-ready RXRDY/TXRDY outputs. Software gains immediate benefit from FIFOs (reduced ISR overhead) and optional flow control - no changes required for basic operation, but updated drivers can leverage FIFO depth and trigger programming for higher throughput. The SC16C550BIB48 delivers measurable performance uplift with zero migration risk.

What crystal frequencies are supported for baud rate generation on the SC16C550BIB48?

The SC16C550BIB48 supports standard crystals including 1.8432 MHz and 3.072 MHz, enabling precise generation of common rates like 9600, 19.2k, 115.2k, and 230.4k bit/s with <0.1 % error. It also accepts external clocks up to 48 MHz on XTAL1 for custom or high-speed applications (e.g., 3 Mbit/s at 5 V requires 48 MHz input). The BAUDOUT pin outputs a 16× baud-rate clock, usable as RCLK for synchronized receiver operation or as a system timing reference. All configurations are software-selectable via DLL/DLM registers.

Is the SC16C550BIB48 pin-compatible with other 16C550-family UARTs, and which packages share identical pinouts?

Yes, the SC16C550BIB48 is pin-compatible with ST16C550, TL16C550, and PC16C550 in LQFP48 packaging - confirmed by NXP's ordering table and pin description documentation. Its LQFP48 footprint (SOT313-2) matches ST16C550CQ48 exactly, including identical placement of D0–D7, A0–A2, IOR/IOW, TX/RX, RTS/CTS, and INT. However, HVQFN32 and PLCC44 variants have different pinouts; only the LQFP48 variant guarantees mechanical and electrical drop-in replacement. The SC16C550BIB48 retains this compatibility while adding DDIS and BAUDOUT not found in some alternatives.