Datasheet

ADS1242, 1243
21
SBAS235H
www.ti.com
APPLICATION EXAMPLES
GENERAL-PURPOSE WEIGHT SCALE
Figure 8 shows a typical schematic of a general-purpose
weight scale application using the ADS1242. In this ex-
ample, the internal PGA is set to either 64 or 128 (depending
on the maximum output voltage of the load cell) so that the
ADS1242
V
REF+
DRDY
SCLK
D
OUT
D
OUT
CS
X
IN
V
DD
GND
A
IN
0
V
DD
2.7V ~ 5.25V
GND
MCLK
A
IN
1
EMI Filter
Load Cell
MSP430x4xx
or other
Microprocessor
V
REF
SPI
X
OUT
EMI Filter
EMI Filter
EMI Filter
load cell output can be directly applied to the differential
inputs of ADS1242.
HIGH PRECISION WEIGHT SCALE
Figure 9 shows the typical schematic of a high-precision
weight scale application using the ADS1242. The front-end
differential amplifier helps maximize the dynamic range.
ADS1242
ADS1243
V
REF+
DRDY
SCLK
D
OUT
D
IN
CS
X
IN
V
DD
GND
A
IN
0
V
DD
2.7V ~ 5.25V
GND
MCLK
A
IN
1
EMI Filter
EMI Filter
Load Cell
OPA2335
G = 1 + 2 R
F
/R
G
MSP430x4xx
or other
Microprocessor
V
REF
SPI
X
OUT
2.7V ~ 5.25V
EMI Filter
EMI Filter
OPA2335
R
F
C
I
R
G
R
F
R
I
R
I
FIGURE 8. Schematic of a General-Purpose Weight Scale.
FIGURE 9. Block Diagram for a High-Precision Weight Scale.