Flow speed detection circuit and associated chip and flow meter

A chip, comprising:

• a flow speed detection circuit, coupled to a first transducer and a second transducer that are external to the flow speed detection circuit, wherein a distance between the first transducer and the second transducer is greater than zero, and a fluid having a flow speed sequentially flows through the first transducer and the second transducer, wherein the flow speed detection circuit comprises:
• a transmitter, coupled to the first transducer, and configured to provide a front signal and a main signal to the first transducer, wherein the first transducer transforms the front signal and the main signal into a transduced signal to the second transducer, and the second transducer transforms the transduced signal into a receiving front signal and a receiving main signal to a receiver;
• and
• the receiver, coupled to the second transducer, wherein the receiver comprises:
• a front signal detection circuit, configured to enable a main signal processing circuit after receiving the receiving front signal;
• and
• the main signal processing circuit, configured to determine the flow speed based on the receiving main signal after being enabled.