Texas Instruments CC2650DK Benutzerhandbuch
ADC
Digital
C
V
in
V
re
f
G
n
d
V
in
V
re
f
G
n
d
V
in
V
re
f
G
n
d
2C
32C
C
V
in
V
re
f
G
n
d
V
in
V
re
f
G
n
d
V
in
V
re
f
G
n
d
2C
32C
Switch Control
Vbias
Data[11:0]
Modules
17.4.8 Analog MUX
Between the analog I/Os and the modules connected to them, there are a set of muxes used to connect
various inputs to the module. These muxes are configured through the AUX ADI.
various inputs to the module. These muxes are configured through the AUX ADI.
These I/Os are mapped to the analog-capable sensor controller pins (AUX IO 0 to 7).
The muxes can connect peripherals to both analog I/Os and some internal signals. The supported
connections are shown
connections are shown
Table 17-19. Supported Connections
Peripheral
Connects to
ADC / Comparator B + (shared input)
AUX IO 0 to 7, GND,VDDS, VDD/DECOUPL
Comparator B -
VDDS, VDD/DECOUPL,GND
Comparator A +
AUX IO 0 to 7
Comparator A-
AUX IO 0 to 7, GND, VDDS, VDD/DECOUPL
To avoid shorting signals together internally TI is providing ROM based driverLib functions which ensure a
break-before-make switching of the internal muxes when connecting them to the analog peripherals.
break-before-make switching of the internal muxes when connecting them to the analog peripherals.
17.4.9 ADC
17.4.9.1 Introduction
The ADC is a 12-bit general-purpose successive-approximation type (SAR) ADC which can sample up to
200 kS/s, using up to 8 different input channels with a number of start triggers.
200 kS/s, using up to 8 different input channels with a number of start triggers.
The input stage consists of a switched-capacitor stage, where the input voltage is sampled and then held
before the conversion is done.
before the conversion is done.
The ADC can operate in both synchronous and asynchronous mode.
In synchronous mode, the start trigger starts the sampling for a programmable amount of time before the
conversion is performed, to allow for high-impedance sources to be properly sampled.
conversion is performed, to allow for high-impedance sources to be properly sampled.
For asynchronous mode the ADC samples continuously, then stops sampling once the start signal
triggers, to perform a conversion. This mode allows jitter-free sampling for applications that require it, such
as audio sampling.
triggers, to perform a conversion. This mode allows jitter-free sampling for applications that require it, such
as audio sampling.
The ADC is production-trimmed and it is possible to compensate for ADC gain and offset errors in
software by reading the factory configuration page.
software by reading the factory configuration page.
Figure 17-2. ADC Block Diagram
17.4.9.2 ADC Reference
The ADC supports two different internal references, one constant and one relative to VDDS.
1205
SWCU117A – February 2015 – Revised March 2015
AUX – Sensor Controller with Digital and Analog Peripherals
Copyright © 2015, Texas Instruments Incorporated