1, four MOS tubes to achieve four 3V and 5V levels of bidirectional conversion, the 2, power input with anti-reverse connection protection, integrated 3.3VLDO, and can provide no more than 150mA external current 3, with power indicator, work or not at a glance 4, can realize UART, IIC, 1-wire, SPI and other bus signals 3V-5V level of bidirectional conversion 1, power input with anti-reverse connection protection, integrated 3.3VLDO, and can provide no more than 150mA external current 2, with power indicator, work or not at a glance 3, can realize UART, IIC, 1-wire, SPI and other bus signals 3V-5V level of bidirectional conversion