ADNS-7530 Avago Technologies US Inc., ADNS-7530 Datasheet - Page 24

• Manufacturer Part Number: ADNS-7530
• Description: Optical Mouse Sensor,DIP
• Manufacturer: Avago Technologies US Inc.

Specifications of ADNS-7530

• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SQUA
Access: Read
Data Type: Upper 8 bits of a 9-bit unsigned integer.
USAGE: SQUAL (Surface Quality) is a measure of the number of valid features visible by the sensor in the current frame.
The maximum SQUAL register value is 242. Since small changes in the current frame can result in
variations in SQUAL when looking at a surface are expected. The graph below shows 800 sequentially acquired SQUAL
values, while a sensor was moved slowly over white paper. SQUAL is nearly equal to zero, if there is no surface below
the sensor. SQUAL is typically maximized when the navigation surface is at the optimum distance from the imaging
lens (the nominal Z-height).
Figure 3. SQUA alues at 00cpi ( hite Paper)
Fig ure . Mean SQUA vs. ( hite Paper)
24
200
150
100
200
150
100
Field
50
50
Bit
0
0
1
1.6
56
Distance of Lens Reference Plane to Surface, Z (mm)
111 166 221 276 331 386 441 496 551 606 661 716 771 826 881
1.8
Address: 0x0
Reset Value: 0x00
SQ
800dpi, Circle@7.5" diameter, Speed-6ips
7
7
2.0
Mean SQUAL vs. Z (White Paper)
At Z = 0 mm, Circle@7.5" diameter, Speed-6ips
2.2
SQ
SQUAL Value (White Paper)
2.4
6
2.6
Count
SQ
2.8
5
5
3.0
3.2
SQ
4
Avg-3sigma
Avg
Avg+3sigma
SQ
3
3
SQ
2
SQ
1
1
changes in SQUAL,
SQ
0
0