Overview

The LC89950 is an IC that provides 1H delay processing for color difference signals used in PAL and SECAM format TV. The LC89950 has two CCD systems, one for the R-Y and one for the B-Y signal, and drives these CCDs with a 4-MHz clock generated within the IC. It uses a sandcastle-shaped three-value input clock with a 1 H (64µs) period.

Features

• 5-V single-voltage power supply

• Two input and output systems, one each for R-Y and B-Y signals

• Takes a sandcastle pulse (SCP) as the input clock, and converts that to a burst gate pulse (BGP) signal internally.

• Generates the CCD drive pulses (4 MHz) from the input clock using a PLL circuit.

• Uses BGP as clamp pulses and clamps the no signal section (back porch) once every horizontal scan period.

• The output signal is in-phase with the input signal