Communication circuit and method utilizing a single communication line

A communication circuit, comprising:

• a) a host apparatus configured as a control chip and having a host sub-circuit, a pulse-width modulation (PWM) circuit, and a host port;
• and
• b) a slave apparatus configured as a power output circuit and having a slave sub-circuit, a power stage circuit, a feedback circuit, and a slave port, wherein said host apparatus and said slave apparatus are coupled by said host port and said slave port via a single communication line, wherein a normal working condition or an abnormal working condition of said slave apparatus is determined based on detecting a condition of said power output circuit;
• c) wherein when said slave apparatus is in said normal working condition, said host sub-circuit is configured to receive a first controlling signal from said PWM circuit, and to generate an output controlling signal that is sent to said slave apparatus through said host port, and said slave sub-circuit is configured to receive said output controlling signal through said slave port, and to generate a second controlling signal for control of said power output circuit to operate in said normal working condition, and
• d) wherein when said slave apparatus is in said abnormal working condition, said feedback circuit is configured to generate a first feedback signal that indicates said abnormal working condition, said slave sub-circuit is configured to receive said first feedback signal, and to provide a feedback controlling signal to said host apparatus through said slave port, and said host apparatus is configured to receive said feedback controlling signal through said host port, and to provide a second feedback signal to said PWM circuit to adjust said first controlling signal such that said power output circuit recovers to said normal working condition.