LTC2410CGN Linear Technology, LTC2410CGN Datasheet - Page 34

• Manufacturer Part Number: LTC2410CGN
• Description: IC ADC 24BIT DIFF INP/REF 16SSOP
• Manufacturer: Linear Technology

Specifications of LTC2410CGN

• Number Of Bits: 24
• Sampling Rate (per Second): 7.5
• Data Interface: MICROWIRE™, Serial, SPI™
• Number Of Converters: 2
• Power Dissipation (max): 1mW
• Voltage Supply Source: Single Supply
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 16-SSOP (0.150", 3.90mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Q894257

APPLICATIO S I FOR ATIO
LTC2410
Traditional high order delta-sigma modulators, while pro-
viding very good linearity and resolution, suffer from po-
tential instabilities at large input signal levels. The propri-
etary architecture used for the LTC2410 third order modu-
lator resolves this problem and guarantees a predictable
stable behavior at input signal levels of up to 150% of full
scale. In many industrial applications, it is not uncommon
to have to measure microvolt level signals superimposed
over volt level perturbations and LTC2410 is eminently
suited for such tasks. When the perturbation is differential,
the specification of interest is the normal mode rejection
for large input signal levels. With a reference voltage
V
range of 5V peak-to-peak. Figures 43 and 44 show mea-
surement results for the LTC2410 normal mode rejection
ratio with a 7.5V peak-to-peak (150% of full scale) input
34
REF
Figure 43. Measured Input Normal Mode Rejection vs Input Frequency with Input Perturbation of 150% Full Scale (60Hz Notch)
Figure 44. Measured Input Normal Mode Rejection vs Input Frequency with Input Perturbation of 150% Full Scale (50Hz Notch)
= 5V, the LTC2410 has a full-scale differential input
U
U
–100
–120
–100
–120
– 60
– 60
–20
–40
–80
–20
–40
–80
0
0
0
0
12.5 25 37.5 50 62.5 75 87.5 100 112.5 125 137.5 150 162.5 175 187.5 200
15
W
30
45
60
U
75
90
INPUT FREQUENCY (Hz)
INPUT FREQUENCY (Hz)
105 120 135 150 165 180 195 210 225 240
signal superimposed over the more traditional normal mode
rejection ratio results obtained with a 5V peak-to-peak (full
scale) input signal. In Figure 43, the LTC2410 uses the
internal oscillator with the notch set at 60Hz (F
and in Figure 44 it uses the internal oscillator with the
notch set at 50Hz (F
rejection performance is maintained with no compromises
in this extreme situation. When operating with large input
signal levels, the user must observe that such signals do
not violate the device absolute maximum ratings.
SYNCHRONIZATION OF MULTIPLE LTC2410s
Since the LTC2410’s absolute accuracy (total unadjusted
error) is 5ppm, applications utilizing multiple synchro-
nized ADCs are possible.
V
V
(150% OF FULL SCALE)
V
V
(150% OF FULL SCALE)
IN(P-P)
IN(P-P)
IN(P-P)
IN(P-P)
= 5V
= 7.5V
= 5V
= 7.5V
O
V
REF
REF
V
F
T
V
REF
REF
V
F
T
= HIGH). It is clear that the LTC2410
O
O
A
A
CC
INCM
CC
INCM
= GND
= 25 C
= 5V
= 25 C
+
–
+
–
= 5V
= 5V
= 5V
= 5V
= GND
= GND
= 2.5V
= 2.5V
2410 F43
2410 F44
O
= LOW)