LM9831CCVJDX

LM9831 42-Bit Color 1200dpi USB Image Scanner October 1999 N Image Scanner LM9831 42-Bit Color, 1200dpi USB General Description The LM9831 is a complete USB image scanner system on a single IC. The LM9831 provides all the functions (image sensor control, illumination control, analog front end, pixel processing function image data buffer/DRAM controller, microstepping motor controller, and USB interface) necessary to create a high performance color scanner. The LM9831 scans images in 42 bit color/14 bit gray, and has output data formats for 24 bit color/8 bit gray. The LM9831 supports sensors with pixel counts of up to 16384 pixels x 3 colors (1200 dpi x 13.6 inches). The LM9831’s low operating and suspend mode supply currents allow design of USB bus-powered scanners. The only additional active components required are an external 4Mbit or 16Mbit DRAM for data buffering and power transistors for the stepper motor. • Stepper motor control tightly coupled with image data buffer management to maximize data transfer efficiency. • PWM stepper motor current control allows microstepping for the price of fullstepping. • USB interface for Plug and Play operation on USB-equipped computers. • Serial EEPROM option for custom Vendor and Product IDs. • Support for USB bus-powered 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 3 channel CCDs and 1 channel CIS sensors. • 3 (R, G, and B) 12-bit, user-programmable gamma correction tables. • Compatible with a wide range of color linear CCDs and Contact Image Sensors (CIS). • Operates with 48MHz external crystal. • Internal bandgap voltage reference. • 100 pin TQFP package Applications • • Color Flatbed Document Scanners Color Sheetfed Document Scanners Key Specifications • • • • • • • Analog to Digital Converter Resolution Maximum Pixel Conversion Rate A4 Color 150dpi scan time A4 Color 300dpi scan time A4 Color 600dpi scan time Supply Voltage - LM9831 - LM9831 DRAM I/O Typical Operating Current Consumption 14 Bits 6MHz