CC864-DUAL Hardware User Guide
1vv0300791 Rev 4.4 – 2011-01-26
Reproduction forbidden without Telit Communications S.p.A’s. written authorization - All Rights Reserved.
Page 49 of 63
3.12. ADC/DAC
Interface
The CC864-DUAL provides three ADC converters and one DAC converter.
Pin No
Name
Description
37
ADC_IN1
Analog/Digital converter input
38
ADC_IN2
Analog/Digital converter input
*)
39
ADC_IN3
Analog/Digital converter input
*)
40
DAC_OUT
Digital/Analog converter output
*
Note:
ADC_IN2 and ADC_3 can not be used on product variants that have active
GPS antenna support.
3.12.1. ADC
Converter
3.12.1.1. Description
The CC864-DUAL provides three on-board ADC converters.
The actual ADC is a Sample and Hold Successive Approximation ADC shared
resource that is multiplexed between many peripherals.
Parameter
Min
Max
Input Voltage Range
0V
2.5 V
Resolution & Accuracy
8 bit
Conversion time
15.4uS
Analog measurement output or sensor output (e.g. battery voltage, temperature) can
be connected to the ADC pin with proper signal conditioning and can be read via AT-
command.
Note:
In a product variant (including the default configuration) where the CC864-
DUAL has external active GPS antenna support, only one of ADC2 or ADC3 can be
used even when the active antenna is turned off. V_ANT_GPS and I_ANT_GPS
monitoring lines are internally connected to these ADCs, and even when switched off,
the configuration will allow sufficient current leakage between channels 2 and 3 to
cause measurement errors.
The conversion time is 15.4uS. An R
in
of 5K maximum with C
in
12pF leads to a
maximum of 233K external resistance to allow proper conversion.
3.12.1.2. Using
ADC
Converter
An AT-command, AT#ADC=1,2, is available to use the ADC function.
The read value is expressed in mV
Refer to SW User Guide or AT Commands Reference Guide for the full description of
this function.
