Original sentence: The WD1770, WD1772, and WD1773 (datasheet images) added an internal digital data separator and write precompensator, eliminating the need for external passive components but upping the clock rate requirement to 8 MHz.The WD2791-WD2797 series (datasheet) added an internal data separator using an analog phase-locked loop, with some external passive components required for the VCO
Edited sentence: The WD1770, WD1772, and WD1773 added an internal digital data separator and write precompensator, eliminating the need for external passive components but upping the clock rate requirement to 8 MHz.The WD2791-WD2797 series added an internal data separator using an analog phase-locked loop, with some external passive components required for the VCO