Holtek has released the HT42B5xx-1 series USB Bridge ICs, designed for various USB product applications. The HT42B5xx-1 series includes four products: HT42B532-1 (USB to I²C), HT42B533-1 (USB to SPI), HT42B534-1 (USB to UART), and HT42B564-1 (USB to UART). The first three, HT42B53x-1, work with USB CDC Class protocols, while HT42B564-1 works with USB HID Class protocols. All of them do not require driver installation.

For old UART product solutions, the HT42B534-1 (USB to UART) can be used to upgrade old products via USB, such as traditional RS-232 blood pressure monitors and electronic scales. The HT42B533-1 (USB to SPI) and HT42B532-1 (USB to I²C), where SPI and I²C can be set in command mode as Master or Slave, can be applied to other data transfer products, such as RF Dongles and other applications.

The HT42B5xx-1 series USB Bridge ICs support Windows XP (SP2)/Vista/7/8/8.1/10, Mac OS X, and Android 4.2 or later operating systems. Holtek offers small package options, including 8-pin SOP, 10-pin SOP, 10-pin MSOP, and 16-pin NSOP, which can save PCB space and simplify product development and upgrading for engineers.