Built-in self-test circuits and semiconductor integrated circuits including the same

A semiconductor integrated circuit comprising:

• a first input multiplexer configured to output a digital input signal by selecting one of a digital test signal and an external digital signal that is provided from an external device outside the semiconductor integrated circuit;
• a digital-to-analog converter configured to perform a first normal conversion operation to generate an analog output signal by converting the digital input signal and provide the analog output signal corresponding to the external digital signal to the external device;
• a second input multiplexer configured to output an analog input signal by selecting one of an analog test signal and an external analog signal that is provided from the external device;
• an analog-to-digital converter configured to perform a second normal conversion operation to generate a digital output signal by converting the analog input signal and provide the digital output signal corresponding to the external analog signal to the external device;
• and
• a built-in self-test circuit configured to, while the digital-to-analog converter performs the first normal conversion operation, perform a real-time monitoring operation to generate a comparison alarm signal based on the digital input signal and the analog output signal, the comparison alarm signal indicating whether the digital-to-analog converter operates normally.

A built-in self-test circuit for monitoring a digital-to-analog converter that generates an analog output signal by converting a digital input signal, the built-in self-test circuit comprising:

• an analog-to-digital converter configured to generate a digital output signal by converting the analog output signal;
• a digital test signal generator configured to generate a digital test signal;
• an input multiplexer configured to output the digital input signal by selecting one of an external digital signal and the digital test signal;
• and
• an on-time monitor configured to, while the digital-to-analog converter performs a normal conversion operation to generate the analog output signal by converting the digital input signal that is output by selecting the external digital signal, perform a real-time monitoring operation to monitor whether the digital-to-analog converter operates normally based on a result of comparing the digital input signal and the digital output signal.