NXP Semiconductors SC16C2550BIB48,128

Overview

SC16C2550BIB48 from NXP Semiconductors is a dual-channel 5 V/3.3 V/2.5 V UART IC with independent 16-byte TX/RX FIFOs, programmable baud rate generators supporting up to 5 Mbit/s at 5 V, and full modem control interface (CTS/RTS/DSR/DTR/RI/CD). It operates across the industrial temperature range and serves as a drop-in upgrade to ST16C2450 in embedded serial communication subsystems for industrial gateways and legacy protocol adapters.

For engineers reviewing the SC16C2550BIB48 datasheet, SC16C2550BIB48 pinout, SC16C2550BIB48 application, or SC16C2550BIB48 equivalent, key selection criteria include dual-channel asynchronous framing support, 4 selectable RX FIFO trigger levels (1/4/8/14 bytes), DMA-ready TXRDY/RXRDY signals, 3-state TTL bus drive, and LQFP48 package compatibility with existing 48-pin UART footprints.

Technical Context

The SC16C2550BIB48 implements two independent UART channels (A and B) with separate address decoding (A0–A2), chip select lines (CSA/CSB), and interrupt outputs (INTA/INTB), enabling concurrent serial data handling without CPU arbitration. Each channel features dedicated 16-byte FIFOs, fully programmable character formatting (5–8-bit data, 1/1.5/2 stop bits, even/odd/no parity), and false start-bit detection.

Its programmable baud rate generator accepts clock inputs up to 80 MHz and divides by any integer from 1 to 65535 to achieve precise rates from DC to 5 Mbit/s; internal loopback mode isolates TX/RX path integrity during diagnostics, while hardware flow control via CTS/RTS and software-controlled modem status registers (MSR/MCR) enable robust RS-232/RS-485 interface management.

Key Specifications

Pinout & Package

SC16C2550BIB48 is housed in a plastic low-profile quad flat package with 48 leads (LQFP48, SOT313-2), body size 7 × 7 × 1.4 mm, lead pitch 0.5 mm, and exposed pad for thermal enhancement. Pin functions are validated per NXP datasheet Rev. 05 (2009), Figure 5 and Table 3.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SC16C2550BIA44 and TL16C2550IPM, the SC16C2550BIB48 uniquely delivers 5 Mbit/s capability in an LQFP48 package with full DMA handshaking (TXRDY/RXRDY), making it optimal for high-throughput, surface-mount industrial controllers requiring minimal CPU intervention.

Availability

SC16C2550BIB48 is available at Aetrix Electronics and suitable for industrial protocol gateways, legacy equipment adapters, multi-channel POS terminals, and secure access controllers requiring stable component supply and long-term manufacturing continuity.

Supply support for SC16C2550BIB48 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 company headquartered in Eindhoven, Netherlands, specializing in secure connectivity solutions for automotive, industrial, and IoT applications.

The SC16C2550BIB48 belongs to NXP's legacy UART product line, designed specifically for robust, pin-compatible upgrades of 16C2450-based systems in industrial automation and communications infrastructure where reliability, mixed-voltage operation, and diagnostic capability are critical.

FAQ

What voltage levels does the SC16C2550BIB48 support, and are level shifters required?

The SC16C2550BIB48 operates natively at 2.5 V, 3.3 V, or 5 V supply voltages and features 5 V-tolerant inputs on data bus pins D7–D0. No external level shifters are needed when interfacing with 5 V microcontrollers or peripherals, simplifying design and reducing bill-of-materials cost. The LQFP48 package maintains consistent electrical characteristics across all three supply rails, verified per NXP datasheet Rev. 05.

How does the SC16C2550BIB48 handle interrupt prioritization between its two UART channels?

The SC16C2550BIB48 implements independent interrupt control per channel via separate INTA and INTB outputs, each driven by a prioritized internal interrupt system. Within each channel, receiver data ready has highest priority, followed by transmitter holding register empty, line status error, and modem status change. The ISR register reports only the highest-priority pending interrupt per channel, requiring sequential servicing to expose lower-priority conditions - a behavior documented in Section 6.4 of the SC16C2550BIB48 datasheet.

Can the SC16C2550BIB48 be used in DMA mode, and what signals enable it?

Yes, the SC16C2550BIB48 supports DMA Mode 1 via the FIFO Control Register (FCR) bit 3. When enabled, TXRDYA/TXRDYB and RXRDYA/RXRDYB become active-low handshaking signals indicating FIFO readiness: TXRDYn asserts when ≥1 empty location exists, RXRDYn asserts when ≥1 received byte is present. These signals directly interface with DMA controller request lines, eliminating CPU polling and enabling block transfers aligned to FIFO trigger levels - a capability confirmed in Section 6.6 of the official datasheet.

What is the function of the OP2A and OP2B pins on the SC16C2550BIB48?

OP2A and OP2B are user-configurable general-purpose outputs tied to Modem Control Register (MCR) bit 3. When MCR[3] = 1, INTA/INTB are enabled and OP2A/OP2B are driven low; when MCR[3] = 0, INTA/INTB enter high-impedance state and OP2A/OP2B are driven high. This mutual exclusion ensures either interrupt signaling or GPIO functionality per channel - a design choice explicitly defined in Table 3 (Pin Description) and Section 5.2 of the SC16C2550BIB48 datasheet.

Is the SC16C2550BIB48 pin-compatible with the ST16C2450, and what initialization behavior occurs at power-up?

Yes, the SC16C2550BIB48 is pin- and functionally compatible with the ST16C2450. At power-up or after RESET assertion, the SC16C2550BIB48 initializes to ST16C2450 compatibility mode - including identical register defaults and interrupt behavior - allowing seamless drop-in replacement without firmware changes. Enhanced features like 16-byte FIFOs and DMA handshaking must be explicitly enabled via software writes to the FCR and MCR registers, as specified in Section 6.1 of the datasheet.