CC2430 Datasheet, PDF (128/212 Pages) Texas Instruments – A True System-on-Chip solution for 2.4 GHz IEEE 802.15.4 / ZigBee-TM

CC2430
13.10 ADC
Peripherals : ADC
13.10.1 ADC Introduction
The ADC supports up to 12-bit analog-to-
digital conversion. The ADC includes an
analog multiplexer with up to eight individually
configurable channels, reference voltage
generator and conversion results written to
memory through DMA. Several modes of
operation are available.
The main features of the ADC are as follows:
• Selectable decimation rates which also
sets the resolution (7 to 12 bits).
• Eight individual input channels, single-
ended or differential
• Reference voltage selectable as internal,
external single ended, external differential
or AVDD_SOC.
• Interrupt request generation
• DMA triggers at end of conversions
• Temperature sensor input
• Battery measurement capability
AIN0
AIN7
VDD/3
TMP_SENSOR
input
mux
Sigma-delta
modulator
Decimation
filter
Int 1.25V
AIN7
ref
AVDD
mux
AIN6-AIN7
Clock generation and
control
Figure 26: ADC block diagram.
13.10.2 ADC Operation
This section describes the general setup and
operation of the ADC and describes the usage
13.10.2.1 ADC Core
The ADC includes an ADC capable of
converting an analog input into a digital
representation with up to 12 bits resolution.
13.10.2.2 ADC Inputs
The signals on the P0 port pins can be used
as ADC inputs. In the following these port pin
will be referred to as the AIN0-AIN7 pins. The
input pins AIN0-AIN7 are connected to the
ADC. The ADC can be set up to automatically
perform a sequence of conversions and
optionally perform an extra conversion from
any channel when the sequence is completed.
It is possible to configure the inputs as single-
ended or differential inputs. In the case where
differential inputs are selected, the differential
inputs consist of the input pairs AIN0-1, AIN2-
3, AIN4-5 and AIN6-7. Note that no negative
of the ADC control and status registers
accessed by the CPU.
The ADC uses a selectable positive reference
voltage.
supply can be applied to these pins, nor a
supply larger than VDD (unregulated power). It
is the difference between the pairs that are
converted in differential mode.
In addition to the input pins AIN0-AIN7, the
output of an on-chip temperature sensor can
be selected as an input to the ADC for
temperature measurements.
CC2430 Data Sheet (rev. 2.1) SWRS036F
Page 128 of 211