DEVICE FOR DERIVING A SAMPLING RATE

• Main Author: ZWAANS, BERNARDUS ANTONIUS MARIA
• Format: Patent
• Language: English
• Published: 05.05.1993
• Subjects: ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; PICTORIAL COMMUNICATION, e.g. TELEVISION

The device comprises a synchronizing-signal separator (20), a phase-locked loop (23), comprising a phase comparator (25), a voltage-controlled oscillator (28) and a frequency divider (31). The device further comprises a gate circuit (26) having an input (S) coupled to the output of the synchronizing-signal separator (20), and an input (5) for receiving a head-change signal (a). The output (36) of the gate circuit (26) is coupled to a control-signal input (37) of the frequency divider (31). The gate circuit (26) is adapted to generate the control signal at a first instant (t1) of a head change and to sustain this control signal until a second instant (t2) of detection of the n-th (preferably the first) synchronizing signal after the head change. The frequency divider (31), which comprises a counter (40), is adapted to inhibit the output signal (d) in response to the control signal, to set the count to a specific value, and to enable the counter at the second instant in order to realize frequency-division.