FT232: The Ultimate USB to UART Solution

The FT232, develop by FTDI Ltd., offers a seamless solution to the old communication problem, enabling USB-equipped systems to communicate effortlessly with serial devices. In today’s digital age, USB has become the ubiquitous interface for communication between devices. However, many legacy systems and embedded devices still rely on older communication protocols such as RS-232, RS-422, and RS-485. This USB-to-serial converter has become a key component in a wide variety of industries, from industrial automation to consumer electronics. In this blog post, we will explore the FT232's history, features, applications, and why it remains one of the most popular choices for USB-to-serial communication.

1. Development History of FTDI FT232

2. What is the FT232?

3. Structure of FT232 Chip

4. FT232 IC Block Diagram

5. How Does FT232 Work?

6. Typical Applications of FT232

7. Packages of FT232

8. FT232 PCB Module Board

9. Frequently Asked Questions [FAQ]

Development History of FTDI FT232

The FT232 chip, developed by FTDI Ltd. (Future Technology Devices International), introduce in the early 2000s to address the growing need for USB-to-serial conversion in embedded systems and industrial applications. As USB became the dominant connectivity standard, many devices still relied on traditional serial communication protocols such as RS-232, RS-422, and RS-485. This created a significant gap in the market, as many legacy systems were not compatible with USB.

FTDI recognized this need and developed the FT232 as a highly integrated solution to convert USB signals into UART (Universal Asynchronous Receiver-Transmitter) signals and vice versa. The FT 232 was one of the first chips to offer a simple, cost-effective way to add USB connectivity to serial devices without requiring complex firmware programming.

Since its introduction, the circuit has become a key component in many industries, from industrial automation and embedded systems to consumer electronics. Over the years, FTDI has expanded the FT 232 family, introducing improved versions such as the FT232R, which included additional features such as an integrated EEPROM, clock generation, and configurable I/O pins. Today, the chip remains a popular choice for engineers and designers looking to bridge the gap between modern USB interfaces and legacy serial communication systems.

What is the FT232?

A USB-to-serial UART interface chip developed by FTDI, designed to facilitate seamless communication between USB-equipped devices and legacy serial devices that use protocols such as RS-232, RS-422, and RS-485. The FT232R is one of the most advanced versions in the FT232 family, integrating all the necessary components for USB to asynchronous serial data transfer in a single chip, eliminating the need for external components or USB-specific firmware programming.

The FT232R is versatile with configurable CBUS I/O pins, UART interface support for various data bits and parity settings, and synchronous/asynchronous bit-bang interface options. It operates across a wide voltage range, from +1.8V to +5V, and can configure for different logic levels. With its integrated features and compact packaging, the FT232R remains a popular choice for adding USB connectivity to serial devices across various applications.

FT232 Alternatives and Equivalents

FTDI offers several alternatives and equivalents to the FT232R, each designed to meet different needs of size, functionality, and application requirements. Here’s an overview of some key FT 232 alternatives:

FT234XD

A single-channel USB to basic UART with USB 2.0 full-speed support, capable of data rates up to 3 Mbaud. It offers 1 CBUS I/O pin and comes in a compact 12-pin DFN package (3mm x 3mm). This chip is ideal for space-constrained designs and applications that do not require the full range of I/O options available with the FT232R.

FT230X

A single-channel USB to UART with full modem control lines (RTS, CTS, DSR, DTR), supporting USB 2.0 full-speed and data rates up to 3 Mbaud. It features 4 configurable CBUS I/O pins and comes in a 16-pin QFN or 16-pin SSOP package. This chip is perfect for applications that require full modem control, such as industrial communication systems, while providing the same high data rate as the FT232R.

FT231X

Similar to the FT230X, the FT231X offers full modem control lines with a USB 2.0 full-speed interface and data rates up to 3 Mbaud. It comes in a 20-pin QFN or 20-pin SSOP package and features 4 configurable CBUS I/O pins. The FT231X suites for more complex systems that need additional I/O options for control or configuration.

FT232H

A high-speed USB to UART/FIFO interface, supporting USB 2.0 Hi-Speed with data rates up to 12 Mbaud. It offers 10 configurable CBUS I/O pins and comes in a 48-pin QFN or 48-pin LQFP package. With its higher data transfer rate, the FT232H is ideal for applications demanding high performance, such as video or audio data transfer, and systems that require more CBUS I/O pins for external devices.

Structure of FT232 Chip

The chip is a highly integrated USB-to-UART interface, designed to simplify USB-to-serial communication. It consolidates several key components into a single package, reducing external components and design complexity.

USB Transceiver: Handles USB physical layer communication, including signal transmission and reception. It also incorporates USB termination resistors.

USB Protocol Engine: Manages USB data transfer and controls USB-specific tasks such as packet framing and CRC checks according to the USB 2.0 specification.

Serial Interface Engine (SIE): Converts between parallel USB data and serial data sent to/from the UART interface, ensuring smooth data flow and proper communication.

UART Controller: Handles serial data transmission and reception, supporting standard UART features like parity, data bits, stop bits, and flow control (RTS/CTS, DTR/DSR).

FIFO Buffers: The circuit includes 128-byte receive and 256-byte transmit buffers, enabling high-speed data transfer and preventing data loss.

Clock Generation: An internal clock generation circuit provides a 12 MHz clock, which use to derive various baud rates for serial communication.

EEPROM: Stores configuration data such as device descriptors, USB identifiers (VID/PID).

CBUS I/O Pins: Configurable pins allow for additional features like LED signaling, power control, and other custom functions.

Power and Reset: The FT 232 integrates a +3.3V LDO regulator for USB operation and a power-on-reset (POR) circuit for reliable startup.

This structure allows the chip to serve as a compact, efficient USB-to-serial interface solution, ideal for various embedded and industrial applications.

FT232 Pinout SSOP-28 :

FT232RQ Pinout QFN-32

The SSOP-28 package offers a compact design with essential UART and USB connections, while the QFN-32 provides additional I/O and features like interrupt signals, reference voltage, and more general-purpose pins. Both packages retain the core functionality of the FT 232 chip, such as USB-to-UART conversion, configurable I/O pins (CBUS), and clock generation.

FT232 IC Block Diagram

The FT232R’s block diagram consists of several components that work together to facilitate USB communication. At the core of the FT232R is the USB Protocol Engine, which manages the USB data transfer protocol. The USB Transceiver handles the physical layer communication between the chip and the USB interface, converting data from USB signals to a form usable by the rest of the chip.

The FIFO RX and TX Buffers (128 bytes receive, 256 bytes transmit) use for smooth data handling between the USB interface and the UART. The Serial Interface Engine (SIE) takes care of parallel-to-serial and serial-to-parallel data conversions, while the Baud Rate Generator ensures that transmit data at the appropriate speed, from 183 baud to 3 Mbaud.

The UART Controller is the core unit that performs serial communication, handling data bit framing, start/stop bits, parity, and data transmission. It also equip with the ability to handle RS-232, RS-422, and RS-485 communication protocols.

How Does FT232 Work?

The FT232R is a versatile USB to serial UART interface chip developed by FTDI. It simplifies the process of adding USB connectivity to devices with RS232, RS485, and RS422 serial communication protocols. This device integrates key components, such as EEPROM, USB termination resistors, and a clock circuit, reducing the need for external parts and making USB to serial designs more efficient.

Key Functional Features:

Fully Integrated Components: The FT232R integrates essential components such as the EEPROM for storing device configurations, USB termination resistors, and clock generation without requiring an external crystal.

Configurable CBUS I/O Pins: It offers five configurable CBUS pins that enable control over various features, such as transmit enable (TXDEN) for RS485, LED indicators for data transmission and reception, and power control for high-power bus-powered designs.

Bit-Bang Modes: The FT232R supports synchronous and asynchronous bit-bang modes, enabling users to configure the UART pins as general-purpose I/O ports for custom applications.

FTDIChip-ID™ Security: Each FT232R device comes with a unique FTDIChip-ID™, which can use for secure software licensing and protection against unauthorized copying.

Data Communication Process:

The FT232R handles the conversion between USB and serial data through its internal Serial Interface Engine (SIE) and USB Protocol Engine. It supports baud rates from 183 baud to 3 Mbaud and can manage standard and non-standard baud rates through its Baud Rate Generator. The device also includes automatic signal inversion and high drive strength, which can configure via EEPROM for customized serial communication.

Typical Applications of FT232

The chip widely use in various applications, particularly for USB to serial communication. It facilitates USB to RS232, RS422, and RS485 conversion, allowing seamless communication between modern USB devices and older serial systems. The FT 232 also commonly use to upgrade legacy peripherals to USB, enabling connectivity for older hardware like printers, scanners, and data acquisition devices.

In the mobile industry, the FT 232 plays a key role in cellular and cordless phone USB data transfer cables and interfaces. Also frequently use to interface MCU/PLD/FPGA-based designs with USB, providing a simple and reliable way to add USB connectivity to custom designs.

Additionally, the chips find in USB audio devices, low bandwidth video data transfer applications, and for transferring data between PDAs and USB systems. They are also integral to USB smart card readers, USB instrumentation, and USB industrial control systems, where they enable reliable data transfer over USB interfaces.

Other notable applications include USB MP3 player interfaces, USB flash card readers and writers, set-top box PC interfaces, and USB digital camera connections. The chip also use in USB hardware and wireless modems, bar code readers, and as a key component in software and hardware encryption dongles, adding security to digital applications.

Packages of FT232

The circuit is available in different packages, making it versatile for various use cases. Some of the most common package types include:

The FT232RL SSOP-28 package measures 5.30mm x 10.20mm, while the FT232RQ QFN-32 has a compact 5.00mm x 5.00mm body.

FT232 Datasheet

FT232RL-R SSOP-28

SSOP28 (5.30mm x 10.20mm) features 28 pins and design for surface-mount applications. It’s ideal for compact, high-density designs.

FT232RL-REEL SSOP-28

Same as the FT232RL-R, but packaged in a reel for automated assembly, making it efficient for mass production.

FT232RL-TUBE SSOP-28

Similar to the FT232RL-R, but packaged in a tube, typically preferred for smaller orders or manual assembly.

FT232RQ QFN-32

The FT232RQ comes in a compact 5.00mm x 5.00mm QFN-32 package with 32 pins, ideal for space-constrained and high-speed USB applications.

FT232RQ-TRAY QFN-32

In a QFN-32 package (5.00mm x 5.00mm) package in a tray, suitable for manual handling and small-batch assembly.

FT232 PCB Module Board

FT232RL USB to TTL UART Driver Board

Designed for high-demand industrial applications, offering reliable USB-to-UART serial communication. It supports 5V, 3.3V, and 1.8V level switching and provides up to 500mA VCC power output, making it versatile and efficient.

Key Features:

High-Speed Performance: Supports data speeds up to 3Mbps, with standard baud rates like 2400, 9600, 115200, and 921600.

Cross-Platform Support: Compatible with Windows, Mac, and Linux (32-bit and 64-bit).

Adjustable Power Supply: Selectable VCC and signal levels (5V, 3.3V, 1.8V) for versatile integration.

High Output Current: Equipped with an independent LDO, it provides up to 500mA of output current, surpassing many similar products.

LED Indicators: Includes LEDs for power, transmission, and reception.

Overcurrent Protection: Integrated 500mA fuse for safety, automatically tripping in case of overcurrent or short circuit.

Comprehensive Pinout: All I/O pins (CTS, RTS, DTR, DSR, RI, DCD) are accessible for easy hardware flow control.

Signal Protection: Built-in protection diodes to prevent damage from abnormal voltage levels.

Compact Design: The 20mm x 50mm size fits within a single USB port, ensuring easy device integration.

Arduino Nano FT232 Driver Compatible with ATMEGA328P CH340

A compact, open-source microcontroller board based on the ATmega328P. An ultra-small platform for simple I/O applications and embedded projects, offering significant advantages in size compared to earlier versions like the Arduino Diecimila. Highly suitable for developing standalone devices or electronic products with interactive capabilities. The Arduino Nano can also use in collaboration with computer software such as Flash, Processing, Max/Msp, PD, and VVVV, allowing for a wide range of creative and interactive projects.

Technical Features of Arduino Nano:

Digital I/O Ports: 12 digital input/output ports (D2 to D13), enabling a wide range of digital operations.

Analog Input Ports: 8 analog input ports (A0 to A7), perfect for sensing analog signals.

Serial Communication: 1 TTL level serial port (RX/TX) for easy communication with other devices.

PWM Support: 6 PWM-enabled ports (D3, D5, D6, D9, D10, D11) for controlling devices like motors or LEDs with variable speeds.

Microcontroller: Powered by the Atmel ATmega328P-AU microcontroller, providing robust performance for embedded applications.

USB Connectivity: Supports USB for programming and power supply, making it easy to connect to a computer or other devices.

External Power Supply: Can power via external 5V to 12V DC or a 9V battery for versatile project designs.

ISP Support: Allows for in-system programming (ISP) for reprogramming the microcontroller.

The Arduino Nano is a highly versatile, cost-effective solution for developing a wide range of interactive and embedded applications, from robotics to sensor networks. The use of the FT232 driver allows for reliable USB-to-serial communication, ensuring seamless interaction with your computer or other USB-enabled devices.

Frequently Asked Questions [FAQ]

What is FT232 used for?

The FT232 is a USB to serial UART interface chip, commonly used to convert USB signals into asynchronous serial data for communication with microcontrollers, sensors, or other serial devices. It simplifies USB connectivity, offering high-speed data transfer (up to 3 Mbps), and widely use in USB-to-serial adapters and embedded systems.

What Is the Difference Between CH340 vs FT232?

The CH340 and FT232 are both USB-to-serial interface chips, but the FT 232 know for its higher reliability, better driver support, and more stable performance at higher data rates. The CH340 is often cheaper but have fewer features, like lower data transfer speeds, and less widespread compatibility with software and operating systems.

How to install FT232RL driver?

To install the FT232RL driver, first download the appropriate driver from the FTDI website. After downloading, run the installation executable and follow the on-screen instructions. For Windows, you need to restart your computer. For Linux or macOS, the driver already pre-install, but you can also install it manually using terminal commands.

What is the Difference Between FT232RL and FT232BL?

The FT232RL and FT232BL are similar USB-to-serial chips, but the FT232RL is the more commonly used version with a wider range of applications. The FT232BL is an earlier version, offering slightly fewer features, such as fewer configurable CBUS pins and lower maximum baud rate options. The FT232RL is more versatile and widely supported.

How does the FT232RL chip typically connect to a host computer?

The FT232RL chip connects to a host computer via a USB cable. It uses the USB interface to convert the data between the computer’s USB protocol and the serial UART protocol, allowing the computer to communicate with external devices like microcontrollers, sensors, and other peripherals that support serial communication.

What is the primary function of the FT232RL chip?

The primary function of the FT232RL chip is to act as a USB-to-serial UART bridge. It converts USB data from a host computer into asynchronous serial data for communication with devices like microcontrollers, sensors, or other serial peripherals. It enables reliable, high-speed data transfer between USB-enabled systems and serial devices.

Conclusion

The FT232 is a highly integrated and versatile solution for bridging the gap between USB and legacy serial communication protocols. Whether you are upgrading older equipment or developing new systems, the FT232 offers ease of use, reliability, and powerful features such as configurable I/O pins, high data transfer rates, and wide compatibility with various logic levels. Its integration of everything from USB protocol handling to EEPROM storage makes it a valuable tool for developers across numerous fields. As technology continues to evolve, the chip will remain an essential building block for USB-to-serial communication, simplifying designs and enhancing the functionality of countless devices.

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