ADNS-7550 Avago Technologies US Inc., ADNS-7550 Datasheet - Page 22

• Manufacturer Part Number: ADNS-7550
• Description: Optical Mouse Sensor,DIP
• Manufacturer: Avago Technologies US Inc.

Specifications of ADNS-7550

• Mounting Style: Through Hole
• Termination Style: Solder Pin
• Supply Voltage: 5 V
• Operating Temperature Range: 0 C to + 40 C
• Product: Optical
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 516-2180; ADNS-7550

SQUAL
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 changes in SQUAL,
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 23. Mean SQUAL vs. Z (White Paper)
22
Figure 22. SQUAL Values at 800cpi (White Paper)
Field
200
150
100
Bit
200
150
100
50
50
0
0
1
1.6
56 111 166 221 276 331 386 441 496 551 606 661 716 771 826
At Z=0mm; Circle = 7.5" diameter; Speed=6ips
1.8
SQ
7
7
Mean SQUAL vs Z (White Paper)
Delta from Nominal Focus (mm)
2.0
At Z=0mm; Circle = 7.5" diameter; Speed=6ips
2.2
SQ
6
SQUAL Value (White Paper)
2.4
6
2.6
Count
2.8
SQ
5
Address: 0x06
Reset Value: 0x00
5
3.0
3.2
SQ
4
4
Avg-3sigma
Avg
Avg+3sigma
SQ
3
3
SQ
2
2
SQ
1
1
SQ
0
0