Datasheet
LTC2480
33
2480fe
For more information www.linear.com/LTC2480
APPLICATIONS INFORMATION
OUTPUT DATA RATE (READINGS/SEC)
0
10
RESOLUTION (BITS)
12
16
18
20
24
10
2480 F23
14
22
30
20
V
IN(CM)
= V
REF(CM)
V
CC
= V
REF
= 5V
V
IN
= 0V
f
O
= EXT CLOCK
RES = LOG 2 (V
REF
/NOISE
RMS
)
T
A
= 25°C
T
A
= 85°C
OUTPUT DATA RATE (READINGS/SEC)
0
10
RESOLUTION (BITS)
12
16
18
22
10
2480 F24
14
20
30
20
V
IN(CM)
= V
REF(CM)
V
CC
= V
REF
= 5V
f
O
= EXT CLOCK
RES = LOG 2 (V
REF
/INL
MAX
)
T
A
= 25°C
T
A
= 85°C
OUTPUT DATA RATE (READINGS/SEC)
0
–10
OFFSET ERROR (ppm OF V
REF
)
–5
5
10
20
10
2480 F25
0
15
30
20
V
IN(CM)
= V
REF(CM)
V
IN
= 0V
f
O
= EXT CLOCK
T
A
= 25°C
V
CC
= 5V, V
REF
= 2.5V
V
CC
= V
REF
= 5V
Figure 23. Resolution (Noise
RMS
≤ 1LSB)
vs Output Data Rate and Temperature
Figure 24. Resolution (INL
MAX
≤ 1LSB)
vs Output Data Rate and Temperature
Figure 25. Offset Error vs Output
Data Rate and Reference Voltage
Figure 26. Resolution (Noise
RMS
≤ 1LSB)
vs Output Data Rate and Reference Voltage
Figure 27. Resolution (INL
MAX
≤ 1LSB)
vs Output Data Rate and Reference Voltage
OUTPUT DATA RATE (READINGS/SEC)
0
10
RESOLUTION (BITS)
12
16
18
20
24
10
2480 F26
14
22
30
20
V
IN(CM)
= V
REF(CM)
V
IN
= 0V
f
O
= EXT CLOCK
T
A
= 25°C
RES = LOG 2 (V
REF
/NOISE
RMS
)
V
CC
= 5V, V
REF
= 2.5V
V
CC
= V
REF
= 5V
OUTPUT DATA RATE (READINGS/SEC)
0
10
RESOLUTION (BITS)
12
16
18
22
10
2480 F27
14
20
30
20
V
IN(CM)
= V
REF(CM)
V
IN
= 0V
REF
–
= GND
f
O
= EXT CLOCK
T
A
= 25°C
RES = LOG 2 (V
REF
/INL
MAX
)
V
CC
= 5V, V
REF
= 2.5V
V
CC
= V
REF
= 5V
frequency. In many applications, the subsequent per-
formance degradation can be substantially reduced by
relying upon the LTC2480’
s exceptional common mode
rejection and by carefully eliminating common mode to
differential mode conversion sources in the input circuit.
The user should avoid single-ended input filters and should
maintain a very high degree of matching and symmetry
in the circuits driving the IN
+
and IN
–
pins.
Second, the increase in clock frequency will increase
proportionally the amount of sampling charge transferred
through the input and the reference pins. If large external
input and/or reference capacitors (C
IN
, C
REF
) are used,
the previous section provides formulae for evaluating the
effect of the source resistance upon the converter perfor
-
mance for any value of f
EOSC
. If small external input and/
or reference capacitors (C
IN
, C
REF
) are used, the effect of
the external source resistance upon the LTC2480 typical
performance can be inferred from Figures 13, 14, 15 and
16 in which the horizontal axis is scaled by 307200/f
EOSC
.
Typical measured performance curves for output data rates
up to 25 readings per second are shown in Figures 20 to
27. In order to obtain the highest possible level of accuracy
from this converter at output data rates above 20 readings
per second, the user is advised to maximize the power
supply voltage used and to limit the maximum ambient
operating temperature. In certain circumstances, a reduc
-
tion of the differential reference voltage may be beneficial.