Summary of FTDI integrates USB 2.0 interface into UART cables
This article describes the FT232H, a USB Hi-Speed bridge chip offering flexible serial and parallel interfaces with speeds up to 40MB/s. It supports protocols like JTAG, SPI, I2C, and UART, featuring on-board voltage regulation for 3.3V/1.8V operation from a 5V source. The text also details two new cables (C232HD-DDHSP-0 and C232HD-EDHSP-0) integrating this IC, providing 1.8m length options with selectable 3.3V or 5V signal levels and optional power output.
Parts used in the FT232H Bridge Chip Project:
- FT232H Hi-Speed USB interface IC
- Serial EEPROM
- Circuit board
- USB connector
- On-board voltage regulator
- Power-on-reset function
- Receive and transmit buffers
- Header socket
Operating at USB Hi-Speed 480Mbps rate, this fast single channel bridge chip features either a flexible serial interface or parallel FIFO interface, with data transfer speeds up to 40Mbytes/s. Using a serial EEPROM interface, this device can be configured for a wide variety of asynchronous and synchronous serial standards, such as JTAG, SPI, I2C and UART as well as synchronous and asynchronous parallel FIFO interfaces. In addition, this device features the new synchronous, half-duplex FT1248 bus, which allows an engineer to trade off bandwidth for pin count using 1, 2, 4, or 8 data lines at up to 30Mbytes/s. The I/O structure is 3.3V with built-in tolerance for 5V, allowing the designer maximum flexibility when interfacing with FPGAs. On-board voltage regulation provides 3.3V and 1.8V supplies from a 5V source, as well as a power-on-reset function. FTDI provides royalty-free virtual com port and D2XX drivers for Microsoft Windows (XP – Windows7), Apple Mac OSX, and Linux. This 48 pin device is available in either LQFP or QFN packaging, and is ROHS compliant.
key hardware fatures
- Single channel USB to serial / parallel ports with a variety of configurations.
- Entire USB protocol handled on the chip. No USB specific firmware programming required.
- USB 2.0 Hi-Speed (480Mbits/Second) and Full Speed (12Mbits/Second) compatible.
- Multi-Protocol Synchronous Serial Engine (MPSSE) to simplify synchronous serial protocol (USB to JTAG, I2C, SPI or bit-bang) design.
- UART transfer data rate up to 12Mbaud. (RS232 Data Rate limited by external level shifter).
- USB to asynchronous 245 FIFO mode for transfer data rate up to 8 MByte/Sec.
- USB to synchronous 245 parallel FIFO mode for transfers up to 40 Mbytes/Sec
- Supports a half duplex FT1248 interface with a configurable width, bi-directional data bus (1, 2, 4 or 8 bits wide).
- CPU-style FIFO interface mode simplifies CPU interface design.
Future Technology Devices International (FTDI) has added two more cables to its USB to digital level serial interface product range.
The devices which interface USB 2.0 with digital level UART cables incorporate the firm’s FT232H Hi-Speed USB interface ICs mounted on a circuit board contained within the USB connector at the end of the cable.
Receive and transmit buffers with 1 kByte capacities allow efficient transfer of high levels of data. The signal levels are either +3.3 V (for the C232HD-DDHSP-0 version) or +5 V (for C232HD-EDHSP-0 version).
The integrated FT232H IC handles all the USB signalling and protocols, facilitating rapid implementation and lowering engineering overheads.
Both the C232HD-DDHSP-0 and C232HD-EDHSP-0 have an optional power output capability with a maximum output current of 200mA at their respective signal voltage level.
The cables, which are 1.8m long, can cope with data transfer rates of up to 12Mbaud.
Both of these cable products have an operational temperature range of -40 °C to +85 °C. They are housed in black cabling with a transparent connector at the end. Individual wires are terminated on to a single header socket.
Typical applications for these product include Flash card readers/writers, bar code scanners, industrial control systems, medical diagnostic equipment, set top box interfaces, USB digital camera interfaces and USB wireless modems.
For more read: FTDI integrates USB 2.0 interface into UART cables
- What is the maximum data transfer speed of the device?
The device supports data transfer speeds up to 40Mbytes/s. - Can the chip handle multiple serial protocols?
Yes, it can be configured for standards such as JTAG, SPI, I2C, and UART. - Does the device require external firmware programming for USB?
No, the entire USB protocol is handled on the chip requiring no USB specific firmware programming. - What voltage supplies does the on-board regulation provide?
It provides 3.3V and 1.8V supplies from a 5V source. - How many data lines can the FT1248 bus use?
The bus allows trade-offs using 1, 2, 4, or 8 data lines. - What are the signal level options for the C232HD cables?
The cables offer either +3.3 V or +5 V signal levels depending on the version. - What is the maximum output current for the cable power capability?
The optional power output capability has a maximum current of 200mA. - What is the operational temperature range for these cables?
The operational temperature range is -40 °C to +85 °C.

