LM9830VJDX

LM9830 36-Bit Color Document Scanner November 1998 N General Description LM9830 36-Bit Color Document Scanner The LM9830 is a complete document scanner system on a single IC. The LM9830 provides all the functions (CCD control, illumination control, analog front end, pixel processing function image data buffer/SRAM controller, microstepping motor controller, and EPP parallel port interface) necessary to create a high performance color scanner. The LM9830 scans images in 36 bit color, and has output data formats for 36 bits, 30 bits, and 24 bits. The only additional active components required are an external SRAM for data buffering and power transistors for the stepper motor. Parallel port pass-through requires two additional TTL/CMOS logic ICs. scan resolution and pixel depth for maximum scan speed. • Stepper motor control tightly coupled with buffer management to maximize data transfer efficiency. • PWM stepper motor current control allows microstepping for the price of fullstepping. • Supports 64k, 128k, or 256k x8 external SRAMs. • Parallel Port interface supports EPP PS2 (bidirectional), or , SPP (nibble) modes of operation. • Pixel depths of 1, 2, or 4 bits are packed into bytes for faster scans of line art and low pixel depth images. • Supports 1 and 3 channel CIS and CCD devices. • 3 (R, G, and B) user-programmable gamma correction tables. • Able to transmit an arbitrary range of pixels to speed up scanning of smaller items (business cards, etc.) by zooming in on a subset of CCD pixels. • Compatible with a wide range of color linear CCDs and Contact Image Sensors (CIS) • Internal bandgap voltage reference. • 100 pin TQFP package Applications • • Color Flatbed Document Scanners Color Sheetfed Document Scanners Features • Scans at up to 6Mpixels/s (2M RGB pixels/sec). • Digital Pixel Processing provides 300, 200, 150, 100, 75, and 50 dpi horizontal resolution from 300dpi sensor, and 600, 400, 300, 200, 150, 100, 75, and 50 dpi horizontal resolution from a 600dpi sensor. • Provides 50-600dpi vertical resolution in 1 dpi increments. • Pixel rate error correction for gain (shading) and offset errors. • Output formats include 12 bit linear, 10 bit linear with shading and offset, or 8 bit gamma corrected, all with 12 bit accuracy. • Multiple CCD clocking rates allows matching of CCD clock to Key Specifications • • • • • • • Analog to Digital Converter Resolution 12 Bits Maximum Pixel Conversion Rate 6MHz A4 Color 150dpi scan (typical, EPP Interface)