AD9844A

a FEATURES 20 MSPS Correlated Double Sampler (CDS) 4 dB ؎ 6 dB Variable CDS Gain with 6-Bit Resolution 2 dB to 36 dB 10-Bit Variable Gain Amplifier (VGA) Low Noise Clamp Circuits Analog Preblanking Function 12-Bit 20 MSPS A/D Converter Auxiliary Inputs with VGA and Input Clamp 3-Wire Serial Digital Interface 3 V Single Supply Operation Low Power: 65 mW @ 2.7 V Supply 48-Lead LQFP Package APPLICATIONS Digital Still Cameras Digital Video Camcorders PC Cameras Complete 12-Bit 20 MSPS CCD Signal Processor AD9844A PRODUCT DESCRIPTION The AD9844A is a complete analog signal processor for CCD applications. It features a 20 MHz single-channel architecture designed to sample and condition the outputs of interlaced and progressive scan area CCD arrays. The AD9844A’s signal chain consists of an input clamp, correlated double sampler (CDS), digitally controlled variable gain amplifier (VGA), black level clamp, and 12-bit A/D converter. Additional input modes are provided for processing analog video signals. The internal registers are programmed through a 3-wire serial digital interface. Programmable features include gain adjustment, black level adjustment, input configuration, and power-down modes. The AD9844A operates from a single 3 V power supply, typically dissipates 78 mW, and is packaged in a 48-lead LQFP. FUNCTIONAL BLOCK DIAGRAM PBLK AVDD AVSS CLPOB DRVDD 4dB؎6dB 2dB~36dB CCDIN CDS 2:1 MUX CLP CLPDM 10 AUX1IN 2:1 MUX AUX2IN CLP INTERNAL REGISTERS DVDD BUF 6 8 BANDGAP REFERENC...