CDCS503 Clock Buffers Texas Instruments CDCS503 Clock Buffers with selectable frequency multiplication stands out from other clock buffers in that it uses an LVCMOS input stage instead of a crystal input stage. The TI CDCS503 accepts a 3.3V LVCMOS signal at the input, includes an output enable pin, and has a PLL that processes the input signal. The PLL of this TI clock buffer features an output frequency either equal to the input frequency or multiplied by the factor of 4.