NXP Semiconductors SC16C550BIA44,518

Overview

SC16C550BIA44,518 from NXP Semiconductors is a 5 V/3.3 V/2.5 V industrial-grade UART IC with 16-byte transmit and receive FIFOs, supporting up to 3 Mbit/s serial data rates at 5 V, pin-compatible with ST16C550/TL16C550/PC16C550, and housed in a PLCC44 package for embedded communication interfaces in legacy industrial control systems.

For engineers reviewing the SC16C550BIA44,518 datasheet, SC16C550BIA44,518 pinout, SC16C550BIA44,518 application, or SC16C550BIA44,518 equivalent, key selection criteria include FIFO-triggered interrupt levels, auto-RTS/CTS hardware flow control, programmable baud rate generator (up to 48 MHz input), 3-state TTL bus interface, and industrial temperature operation (−40 °C to +85 °C).

Technical Context

The SC16C550BIA44,518 implements a full asynchronous serial transceiver 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 functionally identical to the 16C450 after reset, ensuring backward software compatibility.

It supports four programmable receive FIFO interrupt trigger levels (1/4/8/14 bytes), DMA-ready signaling via RXRDY/TXRDY (enabled in PLCC44), and automatic modem handshaking through dedicated RTS/CTS/DSR/DCD/RI/DTR pins - all managed via the Modem Control Register (MCR) and Line Control Register (LCR).

Key Specifications

Pinout & Package

SC16C550BIA44,518 is packaged in plastic leaded chip carrier (PLCC44), SOT187-2, with 44 leads, 1.27 mm pitch, and body size 16.58 × 16.58 × 4.06 mm. The package supports through-hole mounting and provides thermal and mechanical stability for long-life industrial deployment.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL16C550CPN and ST16C550CQ44, SC16C550BIA44,518 delivers broader voltage flexibility (2.5 V/3.3 V/5 V), wider temperature range (−40 °C to +85 °C), and higher sustained data rates - making it the only option qualified for harsh-environment industrial serial infrastructure.

Availability

SC16C550BIA44,518 is available at Aetrix Electronics and suitable for industrial PLC serial gateways, legacy POS terminal interfaces, telecom remote management ports, and medical device diagnostic interfaces requiring stable component supply across extended product lifecycles.

Supply support for SC16C550BIA44,518 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 headquarters in Eindhoven, Netherlands.

The SC16C550BIA44,518 belongs to NXP's legacy industrial UART product line, designed specifically for drop-in replacement of 16C450/16C550-based systems while adding FIFO buffering, hardware flow control, and multi-voltage support for modernization of aging infrastructure.

FAQ

What is the maximum serial data rate supported by the SC16C550BIA44,518?

The SC16C550BIA44,518 supports up to 3 Mbit/s at 5 V with a 48 MHz external clock input. At 3.3 V, the maximum rate is 2 Mbit/s, and at 2.5 V it is 1 Mbit/s. These limits are defined by internal timing margins and are verified per NXP's Product Data Sheet Rev. 6. The SC16C550BIA44,518 achieves this using a 16× oversampled receiver architecture and programmable baud rate divisor registers (DLL/DLM).

Does the SC16C550BIA44,518 support hardware flow control, and how is it configured?

Yes, the SC16C550BIA44,518 supports automatic hardware flow control via RTS and CTS signals. Auto-RTS is enabled by setting bit 5 of the Modem Control Register (MCR), and auto-CTS by setting bit 1 of MCR. When enabled, RTS de-asserts when the RX FIFO reaches a programmed trigger level (1/4/8/14 bytes), and CTS controls transmitter readiness. This behavior is fully implemented in the PLCC44 package used by SC16C550BIA44,518.

Is the SC16C550BIA44,518 pin-compatible with older 16C450-based designs?

Yes, the SC16C550BIA44,518 is pin-compatible with ST16C550, TL16C550, and PC16C550, and powers up to be functionally equivalent to the 16C450. Its PLCC44 footprint matches legacy layouts, and register initialization sequence remains identical. Software written for 16C450 will run unchanged on SC16C550BIA44,518, making it a true drop-in upgrade for FIFO-enhanced performance.

What are the key differences between the SC16C550BIA44,518 and the HVQFN32 variant of the SC16C550B?

The SC16C550BIA44,518 (PLCC44) retains full functionality including TXRDY and RXRDY DMA signaling, BAUDOUT and RCLK pins, and all modem control signals. In contrast, the HVQFN32 variant omits TXRDY/RXRDY, bonds BAUDOUT and RCLK internally, and removes several control pins (AS, CS0–CS2, OUT1/OUT2). Thus, SC16C550BIA44,518 is required for designs needing discrete DMA handshaking or flexible bus decoding.

How does the SC16C550BIA44,518 handle false start-bit detection and framing errors?

The SC16C550BIA44,518 implements hardware-level false start-bit detection to reject spurious transitions that mimic valid start bits, preventing misframing. It also reports framing errors (missing stop bit), parity errors, and break conditions in the Line Status Register (LSR). Each error flag persists until explicitly cleared by reading the corresponding status register, ensuring no fault condition is missed in interrupt-driven applications using SC16C550BIA44,518.