EGS5 Hardware Interface Description
3.16 Analog-to-Digital Converter (ADC)
75
EGS5_HD_v02.004
Page 71 of 123
2012-02-09
Confidential / Released
3.16
Analog-to-Digital Converter (ADC)
The ADC of the EGS5 consists of 2 independent, unbalanced, multiplexed analog inputs that
can be used for measuring external DC voltages in the range of 0mV…+2400 mV. The ADC
has a resolution of 12 bits.
Use the command AT^SRADC described in
to select the analog inputs ADC1_IN or
ADC2_IN, to set the measurement mode and read out the measurement results. The mea-
sured values are indicated in mV with a resolution of 1mV.
There is no out of range detection. Voltages beyond these limits cannot be measured:
•
Underflow: Values
<
-25 mV
•
Overflow: Values > 2425 mV
The measurement repetition interval is adjustable from 100ms up to 30s using AT^SRADC.
When sampling is taking place (for a time ts~400ìs) the conversion switch is closed.
Figure 34:
Analog-to-Digital Converter (ADC)
Please make sure that during Power-down mode the ADCx_IN input voltage does not exceed
±0.3V. Use a RC network as shown in
to reduce the reverse current.
Ri
ADC2_IN
AGND
V1
V2
GSM Module
Application
V1,2 = 0mV...2400mV
=
1.2V
Conversion
Switch
~750k
A
D
ts~400µs
ADC
2x100k
2x100n
Recommended
ADC1_IN
Baseband controller
PORT0
PORT1
KEYC2
KEYC1
AUXADC2
Interface
