ltc2484 Linear Technology Corporation, ltc2484 Datasheet - Page 30

• Manufacturer Part Number: ltc2484
• Description: 24-bit Delta Sigma Adc With Easy Drive Input Current Cancellation
• Manufacturer: Linear Technology Corporation

APPLICATIO S I FOR ATIO
LTC2484
30
Figure 15. +FS Error vs R
Figure 16. –FS Error vs R
Figure 17. +FS Error vs R
–10
–10
–20
–30
–40
–50
–60
–70
–80
–90
500
400
100
300
200
90
80
70
60
50
40
30
20
10
10
0
0
0
0
0
0
V
V
V
V
F
T
V
V
V
V
F
T
V
V
V
V
F
T
O
O
A
CC
REF
IN
IN
A
CC
REF
IN
IN
O
A
CC
REF
IN
IN
= GND
= 25°C
= GND
= 25°C
+
–
+
–
= GND
= 25°C
+
–
C
= 5V
= 5V
= 5V
= 1.25V
= 3.75V
= 3.75V
= 1.25V
C
= 5V
= 5V
REF
= 3.75V
= 1.25V
= 5V
C
C
REF
200
C
10
10
REF
REF
C
U
REF
C
REF
= 0.001µF
REF
C
= 0.01µF
= 0.001µF
= 100pF
REF
= 0.01µF
= 100pF
= 0pF
= 0pF
100
R
100
R
400
R
SOURCE
SOURCE
SOURCE
U
SOURCE
SOURCE
SOURCE
C
REF
(Ω)
(Ω)
600
(Ω)
1k
1k
= 1µF, 10µF
C
at V
at V
at V
REF
C
W
REF
10k
10k
800
REF
REF
= 0.01µF
REF
= 0.1µF
2484 F15
2484 F16
2484 F17
(Small C
(Small C
(Large C
100k
100k
1000
U
REF
REF
REF
)
)
)
leakage current. This leakage current, nominally 1nA
(±10nA max), results in a small gain error. A 100Ω source
resistance will create a 0.05µV typical and 0.5µV maxi-
mum full-scale error.
Output Data Rate
When using its internal oscillator, the LTC2484 produces
up to 7.5 samples per second (sps) with a notch frequency
of 60Hz, 6.25sps with a notch frequency of 50Hz and 6.8ps
with the 50Hz/60Hz rejection mode. The actual output data
rate will depend upon the length of the sleep and data
output phases which are controlled by the user and which
can be made insignificantly short. When operated with an
Figure 18. –FS Error vs R
Figure 19. INL vs Differential Input Voltage and
Reference Source Resistance for C
–100
–400
–200
–300
–500
–10
10
–2
–4
–6
–8
0
8
6
4
2
0
– 0.5
0
V
V
V
T
C
V
V
V
V
F
T
O
A
CC
REF
IN(CM)
A
REF
CC
REF
IN
IN
= GND
= 25°C
= 25°C
C
+
–
= 5V
REF
= 5V
= 1.25V
= 3.75V
= 5V
= 10µF
= 5V
– 0.3
200
= 2.5V
= 1µF, 10µF
– 0.1
400
R
V
SOURCE
IN
/V
SOURCE
REF
600
(Ω)
0.1
(V)
C
R = 500Ω
at V
R = 100Ω
REF
C
R = 1k
REF
800
0.3
= 0.01µF
REF
= 0.1µF
REF
2484 F19
2484 F18
(Large C
> 1µF
1000
0.5
REF
)
2484fa