The MAX3691 serializer is ideal for converting 4-bitwide, 155Mbps parallel data to 622Mbps serial data in ATM and SDH/SONET applications. Operating from a single +3.3V supply, this device accepts low-voltage differential-signal (LVDS) clock and data inputs for interfacing with high-speed digital circuitry, and delivers a 3.3V PECL serial-data output. A fully integrated PLL synthesizes an internal 622Mbps serial clock from a 155.52MHz reference clock.