NXP SC16IS740IPW: A Deep Dive into the Single UART with I2C-bus/SPI Interface Bridge IC
In the world of embedded electronics, efficient communication between microcontrollers and peripheral devices is paramount. Often, a design requires a simple UART (Universal Asynchronous Receiver/Transmitter) interface, but the host controller may have a limited number of serial ports or might only offer digital serial buses like I²C or SPI. This is where bridge ICs become invaluable, and the NXP SC16IS740IPW stands out as a robust and flexible solution for converting between these protocols.
The SC16IS740IPW is a single-channel high-performance UART bridge that provides a complete solution for extending the UART capabilities of a system through either an I²C-bus or SPI serial interface. Its primary function is to seamlessly translate between I²C/SPI and UART protocols, allowing a host microcontroller to communicate with UART-based devices such as sensors, modems, GPS modules, or other legacy equipment without dedicating a precious hardware UART.
Key Features and Architectural Insights
At its core, the SC16IS740IPW contains a powerful UART core capable of data rates up to 5 Mbit/s, which is sufficient for the vast majority of applications. It includes a 64-byte FIFO for both transmit and receive paths, significantly reducing the interrupt loading on the host processor and improving overall system efficiency by minimizing the need for constant attention to data flow.
A critical advantage of this IC is its dual-bus interface capability. The host system can configure the device to communicate over either the I²C-bus (up to 400 kbit/s in Fast-mode) or the SPI interface (up to 4 Mbit/s), offering designers the flexibility to choose the bus that best fits their application's speed requirements or available microcontroller pins. This dual-interface design makes it an exceptionally adaptable component.
Furthermore, the SC16IS740IPW is not just a simple protocol converter. It incorporates full modem control signals (RTS, CTS, DSR, DTR, RI, CD), enabling it to interface directly with modems and other communication equipment. Its register set is fully compatible with the widely used 16C450, making software driver integration straightforward and familiar to engineers.
Typical Applications and System Integration
The versatility of the SC16IS740IPW makes it suitable for a broad range of applications. It is extensively used in:
Embedded Systems: Adding extra UART ports to resource-constrained microcontrollers.
Industrial Automation and Control: Interfacing with legacy industrial equipment that uses RS-232 or RS-485 (with an external transceiver) over a robust I²C or SPI network.
Consumer Electronics: Enabling communication with Bluetooth or Wi-Fi modules that utilize a UART interface.
Telecom Infrastructure: Managing and monitoring subsystems via a central controller using a simple two-wire I²C bus.
Integration into a design is simplified by its small TSSOP-16 package, conserving board space. Operation from a 2.5V to 3.6V supply voltage makes it ideal for modern low-power systems.
ICGOODFIND: The NXP SC16IS740IPW is an indispensable bridge IC that masterfully solves the common problem of UART port scarcity. Its high-speed performance, deep FIFOs, and selectable I²C/SPI host interface provide a future-proof and efficient method for integrating serial devices into digital bus-oriented systems, ensuring design flexibility and reducing processor overhead.
Keywords: UART Bridge, I²C-bus, SPI Interface, FIFO, Protocol Converter.
