LTC2411-1IMS#TRPBF Linear Technology, LTC2411-1IMS#TRPBF Datasheet - Page 30

• Manufacturer Part Number: LTC2411-1IMS#TRPBF
• Description: IC A/DCONV DIFF INPUT&REF 10MSOP
• Manufacturer: Linear Technology

Specifications of LTC2411-1IMS#TRPBF

• Number Of Bits: 24
• Sampling Rate (per Second): 6.8
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 2
• Power Dissipation (max): 1mW
• Voltage Supply Source: Single Supply
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-TFSOP, 10-MSOP (0.118", 3.00mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

APPLICATIO S I FOR ATIO
LTC2411/LTC2411-1
internal calibration and filtering. The noise of the driving
amplifier referred to the converter input and including all
these effects can be calculated as N = n
system noise (referred to the LTC2411/LTC2411-1 input)
can now be obtained by summing as square root of sum
of squares the three ADC input referred noise sources: the
LTC2411/LTC2411-1 internal noise (1.45 V), the noise of
the IN
amplifier.
If the F
f
x-axis is scaled by f
ratio f
decrease, but in the same time the LTC2411/LTC2411-1
30
EOSC
Figure 29. Input Referred Noise Equivalent Bandwidth
of an Input Connected White Noise Source
, Figure 29 can still be used for noise calculation if the
EOSC
+
O
driving amplifier and the noise of the IN
pin is driven by an external oscillator of frequency
Figure 30. Input Normal Mode Rejection,
Internal Oscillator and 50Hz Notch (LTC2411)
1000
–100
–110
–120
100
–10
–20
–30
–40
–50
–60
–70
–80
–90
/153600, the Figure 29 plot accuracy begins to
0.1
10
1
0
0.1
0 f
DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz)
S
INPUT NOISE SOURCE SINGLE POLE
F
1
O
2f
EQUIVALENT BANDWIDTH (Hz)
= HIGH
S
U
EOSC
3f
10
S
4f
S
/153600. For large values of the
100
5f
U
S
F
F
O
O
6f
= HIGH
= LOW
S
1k
7f
S
8f
10k 100k 1M
S
W
9f
S
10f
i
2411 G29
S
11f
• freq
2411 F30
S
12f
S
U
i
. The total
–
driving
noise floor rises and the noise contribution of the driving
amplifiers lose significance.
Normal Mode Rejection and Antialiasing
One of the advantages delta-sigma ADCs offer over con-
ventional ADCs is on-chip digital filtering. Combined with
a large oversampling ratio, the LTC2411/LTC2411-1 sig-
nificantly simplifies antialiasing filter requirements.
The sinc
mode rejection at all frequencies except DC and integer
multiples of the modulator sampling frequency (f
LTC2411/LTC2411-1’s autocalibration circuits further sim-
plify the antialiasing requirements by additional normal
mode signal filtering both in the analog and digital domain.
Independent of the operating mode, f
• f
the maximum output data rate. In the internal oscillator
mode, for the LTC2411, F
setting and f
LTC2411-1, f
oscillator mode, f
The combined normal mode rejection performance is
shown in Figure 30 for the internal oscillator with 50Hz
notch setting (F
oscillator with F
mode. The regions of low rejection occurring at integer
multiples of f
details of the normal mode rejection curves are shown in
OUTMAX
–100
–110
–120
–10
–20
–30
–40
–50
–60
–70
–80
–90
0
0
DIFFERENTIAL INPUT SIGNAL FREQUENCY (Hz)
Figure 31. Input Normal Mode Rejection, Internal
Oscillator and F
4
f
S
digital filter provides greater than 120dB normal
where f
2f
S
S
S
= 15360Hz with a 60Hz notch setting. For the
S
3f
have a very narrow bandwidth. Magnified
O
= 13980Hz (F
S
O
= HIGH) and in Figure 31 for the internal
N
S
4f
= LOW and for the external oscillator
S
is the notch frequency and f
= f
5f
O
S
EOSC
= LOW or External Oscillator
6f
S
S
7f
/10.
= 12800Hz with a 50Hz notch
S
8f
O
S
= LOW). In the external
9f
2411 F31
S
10f
S
S
F
F
f
EOSC
O
O
= 256 • f
= LOW OR
= EXTERNAL OSCILLATOR,
= 10 • f
S
OUTMAX
N
S
= 2048
). The
is