DESCRIPTIONThe AD9991 is a highly integrated CCD signal processor for digital still camera and camcorder applications. It includes a complete analog front end with A/D conversion, combined with a tor is capable of supporting both 4- and 6-phase vertical clocking. A Precision Timing core allows adjustment of high speed clocks with 800 ps resolution at 27 MHz operation.The AD9991 is speci ed at pixel rates of up to 27 MHz. The analog front end includes black level clamping, CDS, VGA, and a 10-bit A/D converter. The timing generator provides all the necessary CCD clocks: RG, H-clocks, V-clocks, sensor gate pulses, substrate clock, and substrate bias control. Operation is programmed using a 3-wire serial interface.Packaged in a space-saving 56-lead LFCSP, the AD9991 is speci- ed over an operating temperature range of 20 C to +85 C.FUNCTIONAL BLOCK DIAGRAMAD9991CDSVGACLAMP10-BITADC10MSHUTSTROBECLOCLIDOUTVREF6dB TO 42dBHORIZONTALDRIVERSV-HCONTROL465RGH1 H4V1 V6VSG1 VSG5VRTVRBPRECISIONTIMINGG FEATURES6-Phase Vertical Transfer Clock SupportCorrelated Double Sampler (CDS)6 dB to 42 dB 10-Bit Variable Gain Ampli er (VGA)10-Bit 27 MHz A/D ConverterBlack Level Clamp with Variable Level ControlComplete On-Chip Timing Generator Precision Timing Core with 800 ps ResolutionOn-Chip 3 V Horizontal and RG Drivers2-Phase and 4-Phase H-Clock ModesElectronic and Mechanical Shutter Modes On-Chip Driver for External CrystalOn-Chip Sync Generator with External Sync Input56-Lead LFCSP Package APPLICATIONSDigital Still CamerasDigital Video CamcordersIndustrial ImagingGENERAL DESCRIPTIONThe AD9991 is a highly integrated CCD signal processor for digital still camera and camcorder applications. It includes a complete analog front end with A/D conversion, combined with a tor is capable of supporting both 4- and 6-phase vertical clocking. A Precision Timing core allows adjustment of high speed clocks with 800 ps resolution at 27 MHz operation.The AD9991 is speci ed at pixel rates of up to 27 MHz. T SPECIFICATIONS 3 Digital Speci cations .3 Anal