The HT6740 is an RF transponder IC with 13.56MHz RF carrier, which provides a low cost batteryless transponder solution when combined with an external inductor. The inductor and internal capacitor form an LC tank which induce voltage from the radiated 13.56MHz carrier signal generated from the reader antenna. HT6740 has a built-in low power RC oscillator which is activated if the induced carrier field strength is high enough to supply the operating current and the response signal (pre-programmed in the OTP memory) is serially transmitted out. The response data is transmitted using PWM/ASK modulation. Modulation of 13.56MHz is accomplished by damping the LC tank with a fixed baud rate.