qt60325 Quantum Research Group, qt60325 Datasheet - Page 34

• Manufacturer Part Number: qt60325
• Description: 32, 48, 64 Key Qmatrix Keypanel Sensor Ics
• Manufacturer: Quantum Research Group

5.7 Timing Limitations
The device requires processing time between bursts, as well
as time to handle communications with the host. With short
burst spacings, long burst lengths, and long intra-burst pulse
spacings, the device can simply run out of available
lQ
Spacing
Spacing
Pulse Spacing = 2µs
Pulse Spacing = 7µs
1,000
2,000
1,000
2,000
Burst
Burst
250
300
400
500
250
300
400
500
Max BL
Max BL
25
50
64
64
64
64
15
30
40
50
64
7
Spacing
Spacing
Pulse Spacing = 3µs
Pulse Spacing = 8µs
1,000
2,000
1,000
2,000
Burst
Burst
250
300
400
500
250
300
400
500
Table 5-2 Permissible Burst Lengths (BL’s)
Max BL
Max BL
10
20
40
64
64
64
12
25
30
50
64
7
© Quantum Research Group Ltd.
Spacing
Spacing
Pulse Spacing = 4µs
Pulse Spacing = 9µs
1,000
2,000
1,000
2,000
Burst
Burst
250
300
400
500
250
300
400
500
34
processing time. When this happens, burst timing and host
communications can slow down and become erratic.
Burst spacings should be verified on an oscilloscope during
development to be certain that the device timings are
preserved and are constant. If not, the burst length and/or
pulse spacing should be reduced.
Max BL
Max BL
10
20
40
64
64
64
12
20
30
40
64
7
Spacing
Pulse Spacing = 10µs
Spacing
Pulse Spacing = 5µs
1,000
2,000
1,000
2,000
Burst
Burst
250
300
400
500
250
300
400
500
www.qprox.com
Max BL
Max BL
10
20
40
50
64
64
10
20
30
40
64
5
Spacing
Pulse Spacing = 6µs
1,000
2,000
Burst
250
300
400
500
QT60xx5 / R1.05
Max BL
15
30
50
64
64
7