NXP Semiconductors SC16C750BIB64,128

Overview

SC16C750BIB64 from NXP Semiconductors is a single-channel 5 V / 3.3 V / 2.5 V UART IC with 64-byte transmit and receive FIFOs, programmable auto-RTS/CTS hardware flow control, and up to 3 Mbit/s serial data rate at 5 V. It serves as a parallel-to-serial/serial-to-parallel bridge in embedded host interfaces requiring high-throughput asynchronous communication with modems or industrial peripherals.

For engineers reviewing the SC16C750BIB64 datasheet, SC16C750BIB64 pinout, SC16C750BIB64 application, or SC16C750BIB64 equivalent, this page delivers verified technical context, LQFP64 package mapping, FIFO-triggered interrupt behavior, DMA-ready TXRDY/RXRDY signaling, and validated alternative options for legacy 16C450/550 upgrade paths.

Technical Context

The SC16C750BIB64 implements a register-mapped UART core with dual 64-byte FIFOs, independent TX/RX baud rate generation via 16× clock division (up to 48 MHz input), and hardware flow control logic that monitors CTS for transmit suspension and asserts RTS based on receive FIFO threshold levels. Its internal loopback mode isolates TX/RX path integrity without external cabling.

It supports three voltage domains (2.5 V, 3.3 V, 5 V), operates across −40 °C to +85 °C, and maintains full software compatibility with 16C450 register sets post-reset while enabling enhanced features-including four selectable FIFO trigger levels, sleep mode (IER[4]), and 3-state TTL bus drivers-via configuration of the Line Control Register (LCR), FIFO Control Register (FCR), and Modem Control Register (MCR).

Key Specifications

Pinout & Package

LQFP64 package (10 × 10 × 1.4 mm, SOT314-2), 64-pin quad flat lead frame with exposed thermal pad; compatible with standard reflow profiles for industrial PCB assembly.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TL16C750IPN, SC16C750BIB64 adds multi-voltage operation critical for power-sensitive industrial designs; versus SC16C752BIB64, it offers lower cost and simpler software initialization for single-link applications where channel density is not required.

Availability

SC16C750BIB64 is available at Aetrix Electronics and suitable for industrial PLC communication, legacy PC serial port upgrades, telecom modem interfaces, and embedded network gateways requiring stable component supply across long product lifecycles.

Supply support for SC16C750BIB64 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 management, and RF technologies.

The SC16C750BIB64 belongs to NXP's legacy UART product line designed specifically for robust, drop-in replacement of 16C450/550-based systems while adding FIFO depth, voltage flexibility, and hardware flow control for industrial and telecom infrastructure.

FAQ

What voltage levels does the SC16C750BIB64 support, and how does it handle mixed-voltage interfacing?

The SC16C750BIB64 operates at 2.5 V, 3.3 V, or 5 V ±10 % supply voltage and features 5 V-tolerant inputs on D7–D0 data pins. This allows direct connection to 5 V logic buses while powered from 3.3 V or 2.5 V rails - eliminating level shifters in mixed-voltage industrial control systems. The SC16C750BIB64 maintains full register compatibility and timing specifications across all three voltage grades without derating.

How does the SC16C750BIB64's auto-RTS/CTS hardware flow control differ from software-based XON/XOFF?

The SC16C750BIB64 implements dedicated hardware logic that monitors CTS input to suspend transmission within one character time and asserts RTS output based on programmable receive FIFO thresholds - all without CPU intervention. Unlike XON/XOFF, which consumes bandwidth and introduces latency, this hardware method prevents FIFO overflow deterministically and supports full 3 Mbit/s throughput. The SC16C750BIB64 achieves this using MCR[5] and MCR[1] bit settings and requires no driver-layer modification.

Can the SC16C750BIB64 replace a 16C450 or 16C550 in an existing design without firmware changes?

Yes - the SC16C750BIB64 powers up in 16C450-compatible mode with identical register addresses and default values. All standard 16C450 software drivers function unchanged. Enhanced features (64-byte FIFO, auto-flow control) are enabled only after writing to specific control registers (e.g., FCR[0], MCR[5]), ensuring zero-impact migration. The SC16C750BIB64 retains pin compatibility with TL16C750 and functional equivalence to 16C450 at power-on reset.

What are the key timing parameters for achieving 3 Mbit/s operation with the SC16C750BIB64?

To achieve 3 Mbit/s, the SC16C750BIB64 requires a 48 MHz clock input (XTAL1 or external source), as its baud generator divides the 16× clock by integer divisors. At 5 V, setup/hold times for D0–D7 relative to IOR/IOW are 10 ns/5 ns; TX rise/fall times are ≤15 ns. The SC16C750BIB64 specifies maximum data rate as 3 Mbit/s only at 5 V - at 3.3 V it is 2 Mbit/s, and at 2.5 V it is 1 Mbit/s - per absolute maximum ratings.

Does the SC16C750BIB64 support DMA transfers, and how are TXRDY/RXRDY signals configured?

Yes - the SC16C750BIB64 supports DMA via TXRDY and RXRDY active-low handshake signals. Their behavior is selected by FCR[3]: in DMA mode 0 (FCR[3]=0), TXRDY goes LOW when FIFO is non-empty and RXRDY goes LOW when ≥1 byte is present; in DMA mode 1 (FCR[3]=1), they assert on FIFO trigger level or timeout. The SC16C750BIB64 supports both single- and multi-transfer DMA bursts without CPU involvement.