BOOSTXL-ADS1219 Hardware Overview
7
SBAU316 – August 2018
Copyright © 2018, Texas Instruments Incorporated
BOOSTXL-ADS1219 BoosterPack™ User's Guide
The analog inputs can range from GND up to AVDD, which is the analog supply voltage. A maximum of
four single-ended inputs, or two differential inputs may be applied to the ADS1219. The user can configure
the input channels through the ADS1219 BoosterPack™ GUI. Each of the analog inputs have a series 1-
k
Ω
resistor with a 100-nF differential capacitor between inputs and a 10-nF common-mode capacitor to
GND for filtering noise and aliasing.
provides a schematic that details the input filtering.
3.2
Voltage Reference
The ADS1219 contains an internal 2.048-V reference and no external reference is required. The analog
supply can also be used as reference input by installing a 0-
Ω
resistor at R7. An external reference can be
applied to the terminal block REFP and REFN connections available on J6 (see the analog input terminal
block in
). The external reference input is limited by a minimum of 0.75 V and a maximum of the
analog supply voltage (AVDD). The REFN input is connected to the board ground by default through the
0-
Ω
resistor R8.
3.3
Digital Interface
The BOOSTXL-ADS1219 interfaces to the MSP-EXP432E401Y LaunchPad™, which in turn
communicates with the computer through USB. The two devices are on the BoosterPack™ and they both
communicate using I
2
C. U4 is an EEPROM used to hold device and board manufacturing information. The
EEPROM information is not currently available to the GUI. U1 is the ADS1219 and communication from
the GUI allows for register read and write as well as ADC conversion data collection.
3.4
BOOSTXL-ADS1219 Digial I/O
The BOOSTXL-ADS1219 EVM supports the I
2
C digital interface and functional modes as described in the
ADS1219 datasheet. The LaunchPad™ operates at a 3.3-V logic and I/O level. The ADS1219 has both
DVDD and AVDD. DVDD is the digital supply and is fixed to the same voltage level as the LaunchPad™
processor so no level shifting is required. The I
2
C communication is through LaunchPad™ ports PN5
(SCL) and PN4 (SDA). GPIO pin control for the
Reset
pin of the ADS1219 is controlled by port PK6. The
Reset
control pin defaults high (not in reset). GPIO port PK7 is an input port pin used to interrupt the
processor when a new conversion result is ready to be read from the ADS1219.
lists the port to
connector pin interface.
Table 4. MSP432E401Y Port to BoosterPack™ Interface
MSP-EXP432E401Y GPIO Port
BOOSTXL-ADS1219 Connector
Pin
SCL (PN5 - Output)
J1:9
SDA (PN4 - Input/Output)
J1:10
RESET (PK6 - Output)
J4:32
DRDY (PK7 - Input)
J4:31
