LTC2408CG Linear Technology, LTC2408CG Datasheet - Page 25

• Manufacturer Part Number: LTC2408CG
• Description: IC A/D CONV 24BIT 8-CHAN 28-SSOP
• Manufacturer: Linear Technology

Specifications of LTC2408CG

• Number Of Bits: 24
• Sampling Rate (per Second): 7.5
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 1
• Power Dissipation (max): 1mW
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 28-SSOP (0.200", 5.30mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIONS
Reference Current (V
Similar to the analog input, the reference input has a
dynamic input current. This current has negligible effect
on the offset. However, the reference current at V
is similar to the input current at full-scale. For large values
of reference capacitance (C
error shift is 0.3ppm/ of external reference resistance
independent of the capacitance at V
the capacitance tied to V
input resistance of up to 20k (20pF parasitic capacitance
at V
Unlike the analog input, the integral nonlinearity of the
device can be degraded with excessive external RC time
REF
) may be tolerated, see Figure 20.
Figure 19. Full-Scale Error vs R
Figure 20. Full-Scale Error vs R
–10
–20
600
500
400
300
200
100
50
40
30
20
10
0
0
1
0
V
V
V
T
V
V
V
T
A
CC
REF
IN
CC
REF
IN
A
= 25 C
= 25 C
= 5V
= 5V
= 5V
= 5V
= 5V
= 5V
200
C
C
10
C
U
VREF
VREF
VREF
RESISTANCE AT V
RESISTANCE AT V
C
VREF
REF
= 1000pF
= 0.01 F
= 100pF
REF
400
100
C
INFORMATION
= 10 F
)
VREF
U
C
VREF
is small (C
VREF
= 0.01 F
600
1k
= 0.1 F
C
REF
REF
> 0.01 F), the full-scale
VREF
( )
( )
C
W
VREF
REF
VREF
= 1 F
VREF
800
10k
VREF
= 0pF
24048 F20
, see Figure 19. If
24048 F19
(Large C)
(Small C)
100k
1000
< 0.01 F), an
U
IN
= V
REF
constants tied to the reference input. If the capacitance at
node V
can tolerate large external resistances without reduction
in INL, see Figure 21. If the external capacitance is large
(C
0.15ppm/
Figure 22.
In addition to the dynamic reference current, the V
protection diodes have a temperature dependent leakage
current. This leakage current, nominally 1nA ( 10nA max),
results in a fixed full-scale shift of 10 V for a 10k source
resistance.
VREF
REF
> 0.01 F), the linearity will be degraded by
160
140
120
100
–20
–10
80
60
20
40
50
40
30
20
10
is small (C
0
Figure 21. INL Error vs R
Figure 22. INL Error vs R
0
0
1
independent of capacitance at V
V
V
V
T
V
T
A
A
CC
REF
CC
REF
= 25 C
= 25 C
= 5V
= 5V
= 5V
= 5V
C
200
C
10
VREF
C
VREF
RESISTANCE AT V
VREF
RESISTANCE AT V
C
C
VREF
C
VREF
VREF
= 0.01 F
= 1000pF
C
VREF
= 100pF
VREF
LTC2404/LTC2408
100
400
= 0pF
= 0.1 F
= 10 F
= 1 F
< 0.01 F), the reference input
600
1k
REF
REF
C
VREF
VREF
VREF
( )
( )
10k
= 0.01 F
800
(Small C)
(Large C)
24048 F22
24048 F21
1000
100k
REF
REF
25
, see
ESD