PixArt Imaging Inc.
ADNS-7530 Integrated Molded Lead-Frame DIP Sensor
VCSEL’s Typical Characteristics
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2.5
V = C
V = A,V
V = C
2.0
40
V = A,V
30
20
10
0
1.5
1.0
0.5
0.0
0
2
4
6
8
10
10
9
11 12 13 14 15
0
1
2
3
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Forward Current, IF (mA)
Forward Current, IF (mA)
Figure 13. Forward Voltage vs. Forward Current for VCSEL
Figure 14. Junction Temperature Rise vs. Forward Current for VCSEL
Motion Pin Timing
Chip Select Operation
The motion pin is a level-sensitive output that signals the
micro-controller when motion has occurred. The motion
pin is lowered whenever the motion bit is set; in other
words, whenever there is data in the Delta_X or Delta_Y
registers. Clearing the motion bit (by reading Delta_X
and Delta_Y, or writing to the Motion register) will put
the motion pin high.
The serial port is activated after NCS goes low. If NCS
is raised during a transaction, the entire transaction is
aborted and the serial port will be reset. This is true for
all transactions. After a transaction is aborted, the normal
address-to-data or transaction-to-transaction delay is
still required before beginning the next transaction. To
improve communication reliability, all serial transac-
tions should be framed by NCS. In other words, the port
should not remain enabled during periods of non-use
because ESD and EFT/B events could be interpreted as
serial communication and put the chip into an unknown
state. In addition, NCS must be raised after each burst-
mode transaction is complete to terminate burst-mode.
The port is not available for further use until burst-mode
is terminated.
LASER Mode
For power savings, the VCSEL will not be continuously on.
ADNS-7530 will flash the VCSEL only when needed.
Synchronous Serial Port
The synchronous serial port is used to set and read pa-
rameters in the ADNS-7530, and to read out the motion
information. The port is a four-wire port. The host
micro-controller always initiates communication; the
ADNS-7530 never initiates data transfers. SCLK, MOSI,
and NCS may be driven directly by a micro-controller.
The port pins may be shared with other SPI slave devices.
When the NCS pin is high, the inputs are ignored and the
output is tri-stated.
The lines that comprise the SPI port:
SCLK: Clock input. It is always generated by the master
(the micro-controller).
MOSI: Input data. (Master Out/Slave In)
MISO: Output data. (Master In/Slave Out)
NCS:
Chip select input (active low). NCS needs to be
low to activate the serial port; otherwise, MISO
will be high Z, and MOSI & SCLK will be ignored.
NCS can also be used to reset the serial port in
case of an error.
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PixArt Imaging Inc.
E-mail: fae_service@pixart.com.tw
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