USB bus interface chip: CH375


The CH375 is a universal interface chip for the USB bus that supports the USB-HOST host mode and the USB-DEVICE/SLAVE device mode. On the local side, the CH375 has an 8-bit data bus and read, write, chip select control lines and interrupt output, which can be easily attached to the system bus of the microcontroller/DSP/MCU/MPU controller. In the USB host mode, the CH375 also provides serial communication mode, which is connected to the MCU/DSP/MPU through serial input, serial output and interrupt output.

The CH375's USB device is fully compatible with the CH372 chip, and the CH375 includes all the features of the CH372. The description of CH375 in USB device mode is not provided in this manual. For related information, please refer to CH372 manual CH372DS1.PDF

The USB host mode of the CH375 supports commonly used USB full-speed devices. The external MCU can communicate with the USB device through the CH375 according to the corresponding USB protocol. The CH375 also has built-in firmware for handling the dedicated communication protocol of the Mass-Storage device. The external MCU can directly read and write common USB storage devices (including USB hard disk/USB flash disk/U disk) in sector-based units.


  • Low-speed and full-speed USB-HOST host interface, compatible with USB V2.0, peripheral components only require crystals and capacitors;
  • Low-speed and full-speed USB device interface, fully compatible with CH372 chip, support dynamic switching host and device mode;
  • Host endpoint input and output buffers are 64 bytes each, supporting 12Mbps full-speed USB devices and 1.5Mbps low-speed devices;
  • Supports control transfer, bulk transfer, and interrupt transfer of USB devices;
  • Automatically detect the connection and disconnection of USB devices, providing event notification for device connection and disconnection;
  • Built-in protocol processor for control transfer, simplifying common control transfers;
  • Built-in firmware handles dedicated communication protocols for mass storage devices, supports USB storage devices with Bulk-Only transport protocol and SCSI, UFI, RBC or equivalent command set (including USB hard drive/USB flash drive/U disk/USB card reader);
  • The MCU reads and writes files in the USB storage device through the U disk file level subroutine library;
  • Parallel interface includes 8-bit data bus, 4-wire control: read operation, write operation, chip select input, interrupt output;
  • The serial interface includes serial input, serial output, interrupt output, and supports dynamic adjustment of communication baud rate;
  • Supports 5V supply voltage and 3.3V supply voltage, supporting low power mode;
  • SOP28 lead-free package, compatible with RoHS, SOP28 to DIP28 conversion board, pin compatible with CH374 chip.


relation files

file name file content
CH374DS1.PDF CH374 datasheet. CH374 is a USB-HOST&DEVICE general interface chip. It supports USB host and USB device, supports 12M USB full-speed communication and 1.5M low-speed communication, supports 8-bit parallel interface or SPI interface, supports all types of USB transmission and Hub operation, etc.
CH372DS1.PDF CH372/CH375/CH376 (device mode) datasheet. Easy-to-use USB-DEVICE general interface chip, used for users to quickly develop USB products. This datasheet introduces the basic transfer commands of USB devices.
CH315DS1.PDF CH315 datasheet. CH315G is a USB1.1 extension cable control chip. The extension distance of network cable can be up to 300 meters. CH315H is a USB signal isolation control chip, used for optoelectronic isolator.
CH376DS1.PDF CH376 datasheet. Easy-to-use USB flash disk and SD card file management chip, supports host-slave USB applications, supports FAT32/FAT16/FAT12, supports SPI/8-bit parallel port/asynchronous serial port. MCU resource occupies less memory. This datasheet introduces USB flash disk and SD card file read/write and management.