ite6801 驱动源码和 Programming 手册，The serial programming output ports are not real open-drain drivers. Sink current is guaranteed by I/O design under the condition of driving the output pin with 0.2V. In a real I 2 C environment, multiple devices and pull-up resistors could be present on the same bus, rendering the effective pull-up resistance much lower than that specified by the I 2 C Standard. When set at maximum current, the serial programming output ports of the IT6801FN are capable of pulling down an effective pull-up resistanc