| 摘要 |
PURPOSE:To improve the accuracy of a cynchronizing type signal detecting circuit by using a multiplication type D/A converter in place of an analog multiplier. CONSTITUTION:The signal to be detected is impressed to an input terminal 14 of a multiplication type D/A converter 12 as an IF input 10 together with a reference signal 26. A clock signal 24 is supplied to a counter 22, and an ROM18 produces a digital since wave output 6 in response to the signal supplied to a counter output 15. Then the output 16 is impressed to the converter 12 through a latch circuit 20 as well as to another D/A converter 28 which compensates the demodulating signal component from the detected signal. Thus a detection output 35 is delivered through a differential integration circuit 30 and an LPF33. |
