LM9831

• 14 bit ADC digitizes at up to 6Mpixels/s (2M RGB pixels/sec).
• Digital Pixel Processing provides 1200, 800, 600, 400, 300, 200, 150, and 100dpi horizontal resolution from a 1200dpi sensor and 600, 400, 300, 200, 150, 100, 75, and 50dpi horizontal resolution from a 600dpi sensor.
• Provides 50-2400dpi vertical resolution in 1 dpi increments.
• Pixel rate error correction for gain (shading) and offset errors.
• Supports 4 or 16Mbit external DRAMs.
• Multiple CCD clocking rates allows matching of CCD clock to scan resolution and pixel depth for maximum scan speed.
• 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

• Color Flatbed Document Scanners
• Color Sheetfed Document Scanners

Positive Supply Voltage (V+=V_A=V_D=V_DRAM)
With Respect to GND=AGND=DGND ...........................................................6.5V
Voltage On Any Input or Output Pin .......................................-0.3V to V⁺+0.3V
Input Current at any pin (Note 3) ..........................................................±25mA
Package Input Current (Note 3) .............................................................±50mA
Package Dissipation at T_A = 25°C (Note 4)
ESD Susceptibility (Note 5)
Human Body Model ..................................................................................2000 V
Machine Model ...........................................................................................250 V
Soldering Information
Infrared, 10 seconds (Note 6) .................................................................235°C
Storage Temperature ................................................................-65°C to +150°

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.