USB bus interface chip: CH374


CH374 is a USB bus universal interface chip, supports USB-HOST host mode and USB-DEVICE/SLAVE device mode, built-in 3-port root hub, supports low-speed and full-speed control transfer, bulk transfer, interrupt transfer and isochronous transfer. At the local end, CH374 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 addition, CH374 also provides SPI serial communication mode for saving I/O pins, which is connected to MCU/DSP/MPU through 3-wire or 4-wire SPI serial interface and interrupt output.


  • Low-speed and full-speed USB-HOST host interface, compatible with USB V2.0, peripheral components only require crystals and capacitors;
  • Supports 1.5Mbps low speed and 12Mbps full speed USB communication, compatible with USB V2.0, peripheral components only need crystal and capacitor;
  • Support USB-HOST host interface and USB-DEVICE device interface, support dynamic switching host mode and device mode;
  • CH374U chip has built-in 3-port USB ROOT-HUB, which can connect and manage 3 USB devices at the same time;
  • Supports control transfer, bulk transfer, interrupt transfer, isochronous transfer of commonly used low-speed and full-speed USB devices;
  • Automatically detects the connection and disconnection of low-speed and full-speed USB devices, providing interrupt notification for device connection and disconnection;
  • Impedance matching series resistor, pull-up resistor on USB device side, pull-down resistor on USB host side of built-in USB signal line;
  • Optional two MCU interfaces: 8-bit passive parallel interface with 6MB speed and SPI serial interface with 3.5MB/28MHz speed;
  • Parallel interface includes 8-bit data bus, 1-bit address, 3-wire control: chip select input, write operation, and optional read operation;
  • The parallel interface only occupies two address bits: the index address port and the data port. The internal index address is automatically incremented after the data port is read or written;
  • The SPI serial interface includes SPI chip select, serial clock, serial input and output, and the SPI output can be connected in parallel with the input;
  • The interrupt output pin is an optional connection that is active low and can be replaced by the interrupt flag bit in the Query Register;
  • Auxiliary functions are provided: programmable clock output, power-on reset output, and optional watchdog reset;
  • Provide U disk file-level subroutine library of FAT12/FAT16/FAT32 file system, enable the MCU to read and write U disk files;
  • Support 5V power supply voltage and 3.3V power supply voltage and even 3V power supply voltage;
  • Available in SOP-28, SSOP-20, SSOP-24 and SOP-16 lead-free packages, compatible with RoHS, DIP28 conversion board available, pin compatible with CH375 and CH372 chips.