ADNB-7051-EV Avago Technologies US Inc., ADNB-7051-EV Datasheet - Page 8

• Manufacturer Part Number: ADNB-7051-EV
• Description: OPT SENSOR BUNDLE SET FOR A7050
• Manufacturer: Avago Technologies US Inc.

Specifications of ADNB-7051-EV

• Description/function: Laser Mouse Bundle
• Interface Type: SPI
• Product: Display Modules
• Touch Panel: No Touch Panel
• For Use With/related Products: ADNS-7050
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

MICROCONTROLLER
Disabling the LASER
LASER_NEN is connected to the gate of a P-channel MOS-
FET transistor which when ON connects VDD to the LA-
SER. In normal operation, LASER_NEN is low. In the case
of a fault condition (ground or VDD3 at XY_LASER), LA-
SER_NEN goes high to turn the transistor off and discon-
nect VDD3 from the LASER.
Single Fault Detection
ADNS-7050 is able to detect a short circuit or fault con-
dition at the XY_LASER pin, which could lead to exces-
sive laser power output. A path to ground on this pin will
8
Figure 6. Single fault detection and eye safety feature block diagram.
SERIAL PORT
FAULT CONTROL
VOLTAGE SENSE
CURRENT SET
BLOCK
ADNS-7050
trigger the fault detection circuit, which will turn off the
laser drive current source and set the LASER_NEN output
high. When used in combination with external compo-
nents as shown in the block diagram below, the system
will prevent excess laser power for a resistive path to
ground at XY_LASER by shutting off the laser. In addition
to the ground path fault detection described above, the
fault detection circuit is continuously checked for proper
operation by internally generating a path to ground with
the laser turned off via LASER_NEN. If the XY_LASER pin
is shorted to VDD3, this test will fail and will be reported
as a fault.
V
DD
GND
LASER_NEN
XY_LASER
V
DD
VCSEL