PAW3601DH-NF Datasheet, PDF (4/35 Pages) Pixart Imaging Inc. – laser diode form a complete and compact laser mouse tracking system

PixArt Imaging Inc.
PAW3601DH-NF
2. Block Diagram and Operation
LD
VSS_LD
CPI
LD
DRIVE
CPI CTRL
XA
QUADRATURE
XB
OUTPUTS
YA
YB
POWER ON
RESET
CMOS
IMAGE
SENSOR
DIGITAL
SIGNAL
PROCESSOR
CMOS Laser Mouse Sensor
VDD
VDDD
VDDA
VSSD
VSSA
5.0V
POWER
3.3V
POWER
PD
SERIAL
INTERFACE
SCLK
SDIO
SERIAL
INTERFACE
CONTROL
REGISTER
OSCILLATOR
Figure 3. Block Diagram
OSCIN
OSCOUT ^RESONATOR
In the traditional optical mouse, it uses LED as a light source. The light illuminates on the working surface and
generates the bright and dark shadow that shows the micro-texture of the surface. The imaging sensor in the
optical mouse chip captures sequential this micro-texture images of the working surface. Based on the captured
images, the optical chip can determine the speed and direction when the optical mouse is moving. Thus, for the
more rough surface, the more obvious shadow image will be generated and much easier to determine the
movement and direction.
The PAW3601DH-NF is a CMOS laser mouse sensor with DSP integration chip that serves as a non-mechanical
motion estimation engine for implementing a computer mouse. It is based on new laser speckle navigation
technology. In the laser mouse, it uses laser diode (LD), specially uses VCSEL (Vertical Cavity Surface Emitting
Laser) as light source, where laser is one kind of coherent light. When this light illuminates on the working
surface, the surface will reflect and diffuse the incident light and generates speckle pattern. The imaging sensor
in the laser mouse chip detects the speckle pattern that generated from the working surface and determines the
movement and direction. Since the speckle pattern can be generated on the most of the surface if this surface is
not perfect smooth or transparent, the laser mouse can adapt on more surfaces as compared with traditional LED-
based optical mouse. The mouse sensor is in a 20-pin optical package. The output format is two-channel
quadrature (X and Y direction), which emulates encoder phototransistors. The current X and Y information are
also available in registers accessed via a serial port. The word "mouse sensor," instead of PAW3601DH-NF, is
used in the document.
All rights strictly reserved any portion in this paper shall not be reproduced, copied or transformed to any other forms without permission.
4
PixArt Imaging Inc.
E-mail: [e-mail]
V2.2, Aug. 2007