An integrated digital BTSC encoder with an improved pilot signal generator
substantially implemented on a single CMOS integrated circuit. By
digitally generating a sinusoid that is frequency locked to a two-state
input reference signal using a high rate internal clock, a
hardware-efficient BTSC pilot signal generator is provided with good
acquisition and tracking performance. Implemented efficiently as a simple
phase detector, a low-complexity loop filter, a pilot frequency offset
adder, a phase accumulator and a sinusoidal generator, the invention
enables lower-rate post-processing of the pilot tone without a costly
variable interpolator decimator structures.