A signal transmitting circuit and a signal receiving circuit for serial communication, and an electronic device are provided. The signal transmitting circuit includes a control module, a first transmitter, a second transmitter, a first differential pin, and a second differential pin, wherein the control module is configured to control the first transmitter to output a first signal via the first differential pin, and control the second transmitter to output a second signal via the second differential pin to record target information with a target signal after differentiating between the first signal and the second signal; and wherein if the target information includes data information and instant information, the data information is recorded in the target signal with a third signal with a first frequency while recording the instant information with a fourth signal with a second frequency, the first frequency is different from the second frequency.