PixArt Imaging Inc.
PAN301BSI-208
CMOS Optical Mouse Sensor
5. Quadrature Mode
The quadrature state of the PAN301BSI-208 tells mouse controller which direction the mouse is moving
in. The output format is two channels quadrature (X and Y direction), which emulates encoder
phototransistors. The DSP generates the ꢀx and ꢀy relative displacement values that are converted into
two channel quadrature signals. The following diagrams show the timing for positive X motion, to the
right or positive Y motion, up.
5.1 Quadrature Output Timing
X motion to the right
Y motion up
XA/YA
83.3us
83.3us
83.3us
83.3us
83.3us
83.3us
FOUR
THREE
TWO
XB/YB
XA/YA
83.3us
166.7us
XB/YB
XA/YA
250us
XB/YB
XA/YA
333.3us
ONE
XB/YB
333.3us @ 3000frames/second
Figure 6. Quadrature output timing
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PixArt Imaging Inc.
13
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V1.1, MAY. 2004