Datasheet ADS1015

0.1 F (typ)
VDD
ADDR
ALERT/RDY
GND
AIN0
AIN1
SCL
SDA
VDD
AIN3
AIN2
ADS1015
Inputs Selected
from Configuration
Register
Output Codes
0-2047
1
2
3
4
10
5
9
8
7
6
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28
ADS1013 , ADS1014 , ADS1015
SBAS473E –MAY 2009–REVISED JANUARY 2018 www.ti.com
Product Folder Links: ADS1013 ADS1014 ADS1015
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Application Information (continued)
9.1.2 Single-Ended Inputs
The ADS1013 and ADS1014 can measure one, and the ADS1015 up to four, single-ended signals. The
ADS1013 and ADS1014 can measure single-ended signals by connecting AIN1 to GND externally. The
ADS1015 measures single-ended signals by appropriate configuration of the MUX[2:0] bits in the Config register.
Figure 25 shows a single-ended connection scheme for ADS1015. The single-ended signal ranges from 0 V up
to positive supply or +FS, whichever is lower. Negative voltages cannot be applied to these devices because the
ADS101x can only accept positive voltages with respect to ground. The ADS101x do not lose linearity within the
input range.
The ADS101x offer a differential input voltage range of ±FSR. Single-ended configurations use only one-half of
the full-scale input voltage range. Differential configurations maximize the dynamic range of the ADC, and
provide better common-mode noise rejection than single-ended configurations.
NOTE: Digital pin connections omitted for clarity.
Figure 25. Measuring Single-Ended Inputs
The ADS1015 also allows AIN3 to serve as a common point for measurements by appropriate setting of the
MUX[2:0] bits. AIN0, AIN1, and AIN2 can all be measured with respect to AIN3. In this configuration, the
ADS1015 operates with inputs, where AIN3 serves as the common point. This ability improves the usable range
over the single-ended configuration because negative differential voltages are allowed when
GND < V
(AIN3)
< VDD; however, common-mode noise attenuation is not offered.
9.1.3 Input Protection
The ADS101x are fabricated in a small-geometry, low-voltage process. The analog inputs feature protection
diodes to the supply rails. However, the current-handling ability of these diodes is limited, and the ADS101x can
be permanently damaged by analog input voltages that exceed approximately 300 mV beyond the rails for
extended periods. One way to protect against overvoltage is to place current-limiting resistors on the input lines.
The ADS101x analog inputs can withstand continuous currents as large as 10 mA.
9.1.4 Unused Inputs and Outputs
Either float unused analog inputs, or tie the unused analog inputs to midsupply or VDD. Connecting unused
analog inputs to GND is possible, but may yield higher leakage currents than the previous options.
Either float NC (not-connected) pins, or tie the NC pins to GND. If the ALERT/RDY output pin is not used, leave
the pin unconnected or tie the pin to VDD using a weak pullup resistor.