HE920 Hardware User Guide
1vv0301014 Rev.9 – 2014-01-23
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Page 62 of 84
12.
DAC and ADC section
12.1.
DAC Converter
12.1.1.
Description
The HE920 module provides a Digital to Analog Converter. The signal (named DAC_OUT)
is available on pad E14 of the HE920 module.
The on board DAC is in the range from 0 to 1023.
However, an external low-pass filter is necessary.
Min
Max
Units
Voltage range (filtered)
0
1.8
Volt
Range
0
1023
Steps
The precision is 1023 steps, so if we consider that the maximum voltage is 1.8V, the
integrated voltage could be calculated with the following formula:
Integrated output voltage = 1.8 * value / 1023
DAC_OUT line must be integrated (for example with a low band pass filter) in order to obtain
an analog voltage.
12.1.2.
Enabling DAC
An AT command is available to use the DAC function.
The command is:AT#DAC[=<enable>[,<value>]]
<value> - scale factor of the integrated output voltage (0..1023 - 10 bit precision)
it must be present if <enable>=1
Refer to SW User Guide or AT Commands Reference Guide for the full description of this
function.
NOTE:
The DAC frequency is selected internally. D/A converter must not be used during
POWERSAVING.
