Avnet AES-ATT-M18QWG-SK-G, Hardware User'S Manual

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Page 27
3.4.6 ADC / Ambient Light Sensor (JP2)
A single ADC input is provided on the WNC module.

This inputs to a 16 bit convertor, sampled at 2.4MHz for an ENOB of 15 bits

Analog Input Bandwidth is 100 kHz (typical)

The ADC’s input range is 0.1V to 1.7V
A shorting link across jumper JP2 connects one of the following sources to this ADC input:
Table 9
– ADC Input Source Selector (JP2)
Note!
Two issues should be noted that limit the utility of the ADC input on the initial production boards:
a) ADC input source selection via JP2 is not possible unless th
e R50 “default” resistor is removed
b)
The ADC’s input voltage limit could be exceeded if the Ambient Light Sensor is exposed to an
excessively bright light source, resulting in potential damage to the module. To prevent this, it is
recommended that light-levels must be restricted using some form of optical filter placed over the
U3 light sensor (see U3 location below)
Figure 13
– Board Detail Showing Light Sensor (U3)
JP2 Pins Signal Source for ADC Input
1 & 2 (default)
Ambient Light Sensor output (U3)
2 & 3
Expansion Connector (J1 pin 4)
(ie. driven by an external circuit)