VT5363

Design notes

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2.7

Driving the navigation LED

The VT5363 provides an output (NAV_LED) for driving the LED used to illuminate the

mousing surface. This output is active HIGH but cannot be used to drive the navigation LED

directly. An external NPN bipolar transistor is recommended as shown in the reference

schematic. The maximum current through the LED is controlled by a resistor (R1 on the

Reference Schematic).

2.8

LNK_LED output

The VT5363 has an output (LNK_LED) which is high whenever the mouse is active (i.e.

connected to a PC which is not in a suspend state).

The user does not need to use this output to produce a working mouse but it may be used to

drive an additional LED for cosmetic purposes. An external bipolar transistor is required in

the same way as the navigation LED.

2.9

Optical centre

The optical centre of the VT5363 is NOT in the centre of the package, it is offset by -

0.243mm in the X-axis and 0.215mm in the Y axis with respect to the centre of the package

as shown below. The PCB designer must take this into account when laying out the PCB.

Figure 4.

VT5363 optical centre

Optical centre (-0.243mm, +0.215mm)

mechanical centre

of package (0,0)

pin 1 marking

TOP VIEW OF VT5363