Datasheet

ADC1203Y
V
A
+
0.01 uF 0.1 uF 10 uF
0.01 uF 0.1 uF 10 uF
0.01 uF 0.1 uF 10 uF
LM4041-ADJ
2k
+5.0V
V
D
+
V
REF
+
V
REF
-
+2.048V
DGNDAGND
ANALOG INPUT VOLTAGE
GROUND REFERENCE
CH0
CH2
CH4
or
CH6
COM
ASSIGNED
(+) INPUT
ASSIGNED
(-) INPUT
+5.0V
ANALOG
INPUT
VOLTAGE
ANALOG INPUT
VOLTAGE RANGE
2.5V +/- 2.048V
12-BITS SIGNED
LM4040-2.5
1M
1k
+
-
ADC1203Y
V
A
+
0.01 uF 0.1 uF 10 uF
0.01 uF 0.1 uF 10 uF
0.01 uF 0.1 uF 10 uF
LM4040-2.5
1k
+5.0V
V
D
+
V
REF
+
V
REF
-
+2.5V
DGNDAGND
ANALOG INPUT VOLTAGE
GROUND REFERENCE
CH0
CH2
CH4
or
CH6
COM
ASSIGNED
(+) INPUT
ASSIGNED
(-) INPUT
1M
+
-
ANALOG
INPUT
VOLTAGE
ANALOG INPUT
VOLTAGE
RANGE
0V to 5V
ADC12030, ADC12032, ADC12034
ADC12038, ADC12H030, ADC12H032
ADC12H034, ADC12H038
SNAS080K –JULY 1999–REVISED MARCH 2013 www.ti.com
In the circuit of Figure 67, some voltage range is lost since the amplifier will not be able to swing to +5V and
GND with a single +5V supply. Using an adjustable version of the LM4041 to set the full scale voltage at exactly
2.048V and a lower grade LM4040D-2.5 to bias up everything to 2.5V as shown in Figure 68 will allow the use of
all the ADC's digital output range of −4096 to +4095 while leaving plenty of head room for the amplifier.
Fully differential operation is shown in Figure 69. One LSB for this case is equal to (4.1V/4096) = 1 mV.
Figure 67. Alternative Pseudo-Differential Biasing
Figure 68. Pseudo-Differential Biasing without the Loss of Digital Output Range
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Product Folder Links: ADC12030 ADC12032 ADC12034 ADC12038 ADC12H030 ADC12H032 ADC12H034
ADC12H038