NXP Semiconductors SC16C550BIBS,151

Overview

SC16C550BIBS,151 from NXP Semiconductors is a 32-pin HVQFN UART IC that converts parallel CPU data to serial streams and vice versa for industrial RS-232/RS-485 interface systems. It delivers 16-byte transmit/receive FIFOs, programmable baud rates up to 3 Mbit/s at 5 V, auto-RTS/CTS hardware flow control, and operates across 2.5 V/3.3 V/5 V supply rails in −40 °C to +85 °C ambient.

For engineers reviewing the SC16C550BIBS,151 datasheet, SC16C550BIBS,151 pinout, SC16C550BIBS,151 application, or SC16C550BIBS,151 equivalent, key selection factors include its HVQFN32 package constraints (no TXRDY/RXRDY signals), 16-byte FIFO interrupt trigger level configurability, 5 V-tolerant data bus pins, and compatibility with legacy 16C450 software stacks in embedded controller and industrial gateway designs.

Technical Context

The SC16C550BIBS,151 implements a dual-path asynchronous serial interface with independent transmitter and receiver shift registers, a shared 16× baud rate generator clocked up to 48 MHz, and register-mapped control logic compliant with industry-standard 16C450 addressing. Its internal loopback mode enables link-layer diagnostics without external hardware.

It supports four receive FIFO interrupt trigger levels (1/4/8/14 bytes), programmable character framing (5–8 data bits, 1/1.5/2 stop bits, even/odd/no parity), and modem status monitoring via DSR/DCD/RI/CTS inputs with change-detection interrupts. The HVQFN32 variant omits TXRDY and RXRDY signals and bonds BAUDOUT internally to RCLK.

Key Specifications

Pinout & Package

HVQFN32 package with 5 mm × 5 mm body, 0.5 mm pitch, and exposed thermal pad requiring soldering to PCB ground plane per NXP SOT617-1 specification.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL16C550CPTR and ST16C550CQ44, the SC16C550BIBS,151 uniquely combines HVQFN32 miniaturization, triple-voltage operation, and industrial temperature range - making it optimal for space-constrained, multi-rail embedded systems where thermal management and software compatibility are critical.

Availability

SC16C550BIBS,151 is available at Aetrix Electronics and suitable for industrial PLC backplanes, embedded gateway modem interfaces, POS terminal peripheral hubs, and ruggedized vehicle telematics units requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SC16C550BIBS,151 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.

The SC16C550BIBS,151 belongs to NXP's legacy UART product line designed specifically for industrial-grade serial communication bridging in resource-constrained embedded systems requiring long-term availability and software compatibility.

FAQ

What voltage levels does the SC16C550BIBS,151 support, and how does that affect system design?

The SC16C550BIBS,151 operates at 2.5 V, 3.3 V, or 5 V ±10 %, enabling direct integration into mixed-voltage systems without level-shifting circuitry. Its 5 V-tolerant D0–D7 inputs allow connection to legacy 5 V microcontrollers, while 2.5 V mode reduces dynamic power in battery-backed applications. This flexibility simplifies power architecture in industrial gateways where multiple voltage domains coexist.

Does the SC16C550BIBS,151 support hardware flow control, and how is it implemented?

Yes, the SC16C550BIBS,151 supports full auto-RTS and auto-CTS hardware flow control. RTS is asserted when the RX FIFO has space above a user-configurable trigger level (1/4/8/14 bytes); CTS is monitored by the TX engine to gate data emission. This eliminates RX FIFO overrun without CPU intervention - critical for reliable modem and sensor interface applications where data bursts exceed host processing latency.

Why does the SC16C550BIBS,151 lack TXRDY and RXRDY signals compared to other SC16C550B variants?

The SC16C550BIBS,151 uses the HVQFN32 package (SOT617-1), in which TXRDY and RXRDY signals are omitted per NXP's package-specific implementation. These DMA-ready signals are present only in PLCC44, LQFP48, and DIP40 variants. Designers requiring DMA handshaking must select SC16C550BIA44, SC16C550BIB48, or SC16C550BIN40 instead - the SC16C550BIBS,151 targets interrupt-driven or polled I/O architectures.

How does the SC16C550BIBS,151 ensure compatibility with legacy 16C450 software?

Upon reset, the SC16C550BIBS,151 initializes all registers to match the 16C450 register map and behavior, including identical I/O port addresses and bit definitions. This allows unmodified DOS, BIOS, and Linux kernel serial drivers to operate without patching. The 16-byte FIFOs remain disabled by default, preserving 16C450 timing until explicitly enabled via the FIFO Control Register - ensuring seamless software migration.

What thermal considerations apply to the SC16C550BIBS,151's HVQFN32 package?

The SC16C550BIBS,151's HVQFN32 package features an exposed thermal pad (pin 15) that must be soldered to a PCB ground plane with thermal vias for effective heat conduction. NXP specifies this pad as essential for electrical stability and thermal performance - omitting it risks latch-up or parametric drift at maximum junction temperature. Board layout must allocate ≥12 thermal vias (0.3 mm diameter) under the pad to meet industrial ambient requirements.