Abstract: The present invention provides a detection circuit, which comprises a first detection path and a second detection path for detecting the state of a power source under test. A first current is generated on the first detection path according to power source under test; a second current is generated on the second detection path according to the power source under test. The detection circuit generates a detection signal according to the first current and the second current. The detection signal represents the state of the power source under test.

Abstract: The present invention relates to a transmission interface device capable of calibrating the transmission frequency automatically, which comprises a clock generating unit, a data transmission unit, and a control unit. The clock generating unit is used for generating an operating clock, which determines a transmission frequency. The data transmission unit is used for connecting to a host and transmitting a plurality of data to the host or receiving the plurality of data from the host according to the operating clock. When the host or the data transmission unit detects transmission errors in the plurality of data, the host or the data transmission unit generates an error handling. The control unit generates an adjusting signal according to the error handling and transmits the adjusting signal to the clock generating unit for adjusting the transmission frequency of the operating clock.