LTC2401 Linear Technology, LTC2401 Datasheet - Page 8

• Manufacturer Part Number: LTC2401
• Description: 1-/2-Channel 24-Bit uPower No Latency ADC in MSOP-10
• Manufacturer: Linear Technology

APPLICATIO S I FOR ATIO
LTC2401/LTC2402
removed by the FS
scale output of the ADC (data out = FFFFFF
at V
due to R
The absolute zero output of the ADC (data out = 000000
occurs at V
have negligible errors due to the 1nA (typ) leakage current
at pins FS
range (– 300mV to 5.3V) and low noise (0.6ppm RMS)
enable the LTC2401 or the LTC2402 to directly digitize the
output of the bridge sensor.
8
IN
I
EXCITATION
= V
P2
B
= FS
SET
are removed by the ground sense input ZS
IN
R
R
V
V
P1
P2
B
A
= V
, ZS
Figure 3. Half-Bridge Digitizer with
Zero-Scale and Full-Scale Sense
SET
I
I
I
A
DC
DC
DC
R
R
R
, see Figure 4. Similarly, the offset errors
SET
P3
P4
P5
SET
= ZS
= 0
= 0
= 0
U
2
3
5
6
input to the ADC. The absolute full-
and V
SET
FS
V
GND
ZS
IN
LTC2401
SET
SET
U
. Parasitic resistors R
THERMISTOR
V
CC
IN
1
SDO
SCK
. The wide dynamic input
CS
F
100
O
12k
9
8
7
10
W
24012 F03
3-WIRE
SPI INTERFACE
Figure 5. Isolated Temperature Measurement
COLD JUNCTION
THERMOCOUPLE
+
HEX
) will occur
U
2.7V TO 5.5V
P3
–
to R
HEX
SET
1
2
3
4
5
P5
V
FS
CH1
ZS
CH0
)
.
CC
SET
SET
LTC2402
The LTC2402 is ideal for applications requiring continu-
ous monitoring of two input sensors. As shown in
Figure 5, the LTC2402 can monitor both a thermocouple
temperature probe and a cold junction temperature sen-
sor. Absolute temperature measurements can be
performed with a variety of thermocouples using digital
cold junction compensation.
The selection between CH0 and CH1 is automatic. Initially,
after power-up, a conversion is performed on CH0. For
each subsequent conversion, the input channel selection
SDO
GND
SCK
Figure 4. Transfer Curve with Zero-Scale and Full-Scale Set
CS
F
O
10
9
8
7
6
00000
FFFFF
H
H
ISOLATION
BARRIER
ZS
SET
PROCESSOR
24012 F05
V
IN
FS
SET
24012 F04
12.5%
EXTENDED
RANGE
12.5%
EXTENDED
RANGE