The FT232RL is a USB to serial UART interface controller manufactured by FTDI (Future Technology Devices International). It is a part of the FTDI's FT232 family of USB-to-UART interface ICs. The FT232RL chip has an LQFP (Low-profile Quad Flat Package), with a pin count of 28 pins.
FT232RL Pinout and Function Description (28 Pins)
Here is the detailed description of the 28 pins and their functions:
Pin Number Pin Name Pin Type Function Description 1 VCC Power 3.3V or 5V power supply (depending on device configuration). 2 GND Ground Ground connection. 3 TXD Output Transmit data, sends serial data from the FT232RL to the target device. 4 RXD Input Receive data, receives serial data from the target device. 5 DTR Output Data Terminal Ready. Used in hardware flow control for communication initiation. 6 RTS Output Request To Send. Used in hardware flow control, signals readiness to transmit data. 7 CTS Input Clear To Send. Used in hardware flow control, indicates if the receiver can accept data. 8 DSR Input Data Set Ready. Used in hardware flow control to indicate if the target device is ready. 9 RI Input Ring Indicator. Used for modem connections, indicates the presence of a phone call. 10 USB- Signal Negative signal line for USB communication. 11 USB+ Signal Positive signal line for USB communication. 12 VBUS Power USB power input (typically 5V). 13 /RESET Input Reset pin, active low, used to reset the FT232RL chip. 14 SUSPEND Input Used to indicate suspend mode on the USB. 15 3V3OUT Output 3.3V output for powering low-voltage devices or logic. 16 ACBUS[0] I/O Alternate function I/O pin, used in various configurations such as GPIO. 17 ACBUS[1] I/O Alternate function I/O pin, used in various configurations such as GPIO. 18 ACBUS[2] I/O Alternate function I/O pin, used in various configurations such as GPIO. 19 ACBUS[3] I/O Alternate function I/O pin, used in various configurations such as GPIO. 20 ACBUS[4] I/O Alternate function I/O pin, used in various configurations such as GPIO. 21 ACBUS[5] I/O Alternate function I/O pin, used in various configurations such as GPIO. 22 ACBUS[6] I/O Alternate function I/O pin, used in various configurations such as GPIO. 23 ACBUS[7] I/O Alternate function I/O pin, used in various configurations such as GPIO. 24 RD# Input Read input, used for accessing data in the target device (specific to FTDI devices). 25 WR# Output Write output, used for writing data to the target device (specific to FTDI devices). 26 OE# Output Output Enable, used for controlling data flow (specific to FTDI devices). 27 ACBUS[8] I/O Alternate function I/O pin, used in various configurations such as GPIO. 28 ACBUS[9] I/O Alternate function I/O pin, used in various configurations such as GPIO.Circuit Principle and Instructions:
The FT232RL interfaces with a USB host (like a PC) via its USB port (pins 10 and 11), providing a USB-to-UART bridge, which allows data transmission to a serial device using the RXD (pin 4) and TXD (pin 3). It can support full hardware flow control using pins such as RTS, CTS, DTR, and DSR. Additionally, it has the ability to be reset using the RESET pin (pin 13) and can provide power to low-power devices with the 3.3V output (pin 15).
FT232RL Pin Function FAQ (20 Common Questions)
1. What is the purpose of the TXD pin in the FT232RL (Pin 3)?The TXD pin is used to transmit serial data from the FT232RL to the target device, such as a microcontroller or another UART device.
2. Can I use the FT232RL with a 3.3V supply?Yes, the FT232RL supports both 3.3V and 5V power supplies, depending on the configuration of the device.
3. What is the function of the DTR pin (Pin 5)?The DTR pin (Data Terminal Ready) is used for hardware flow control, indicating to the target device that the FT232RL is ready to communicate.
4. What does the RTS pin (Pin 6) do?The RTS pin (Request To Send) is used in hardware flow control to signal that the FT232RL is ready to send data to the target device.
5. How does the FT232RL handle flow control?The FT232RL uses pins such as RTS, CTS, DTR, and DSR to implement hardware flow control, ensuring reliable data transmission between devices.
6. What is the role of the RI pin (Pin 9)?The RI pin (Ring Indicator) is used in modem applications to indicate if there is an incoming call or ring signal.
7. What does the USB- (Pin 10) and USB+ (Pin 11) pins do?These pins are the differential signal lines for USB communication. USB+ is the positive signal, while USB- is the negative signal.
8. Can I use the FT232RL in low-power applications?Yes, the FT232RL can provide a 3.3V output (Pin 15), which can be used to power low-voltage devices.
9. What does the RESET pin (Pin 13) do?The RESET pin is used to reset the FT232RL device, and it is active low, meaning pulling it low will reset the chip.
10. What is the function of the SUSPEND pin (Pin 14)?The SUSPEND pin indicates whether the USB device is in suspend mode, which reduces power consumption.
11. How do I configure the FT232RL for different I/O functions?The FT232RL allows configuration of alternate function pins (ACBUS pins) for general-purpose I/O or other tasks as required by the application.
12. What is the use of the 3V3OUT pin (Pin 15)?The 3V3OUT pin provides a 3.3V output that can be used to power external low-voltage devices or components.
13. Can I use the FT232RL for modem communications?Yes, the FT232RL supports modem signals like RI, DSR, and DTR, making it suitable for communication with modems.
14. What happens if the VCC pin is not powered properly?If the VCC pin is not powered, the FT232RL will not operate and will not establish any communication with the host device.
15. How do I reset the FT232RL?To reset the FT232RL, pull the RESET pin low, which will restart the chip.
16. Can the FT232RL be used with a 5V supply?Yes, the FT232RL supports 5V supply voltages and is compatible with both 5V and 3.3V logic levels.
17. How do I use the ACBUS pins on the FT232RL?The ACBUS pins (Pins 16 to 28) are configurable for alternate functions, including GPIO or special functions depending on the configuration.
18. What is the maximum speed supported by the FT232RL?The FT232RL supports data transfer speeds up to 3 Mbps.
19. What should I do if there is no communication from the FT232RL?If there is no communication, check the power supply, ensure correct wiring, and verify that the RESET pin is not held low.
20. Is the FT232RL compatible with all operating systems?Yes, the FT232RL is supported on most major operating systems, including Windows, Linux, and macOS, with appropriate drivers installed.
This provides a comprehensive guide on the FT232RL, including its pinout, function, and a detailed FAQ.
