Datasheet

LTC2451
16
2451fg
TYPICAL APPLICATIONS
Easy Passive InputEasy Active Input
LTC2451
100nF
PRECONDITIONED SENSOR
WITH VOLTAGE OUTPUT
1k
V+
GND
V
OUT
2451 TA02
LTC2451
100nF
R
S
< 1k
2451 TA03
Figure 15. LTC2451 Input Signal Attenuation
vs Frequency (Low Frequencies)
INPUT SIGNAL FREQUENCY (Hz)
0
INPUT SIGNAL ATTENUATIOIN (dB)
–20
–10
0
480
2451 F15
–30
–40
–25
–15
–5
–35
–45
–50
12060
240180
360 420 540
300
600
For a simple system noise analysis, the input drive cir-
cuit can be modeled as a single-pole equivalent circuit
characterized by a pole location, f
i
, and a noise spectral
density, n
i
. If the converter has an unlimited bandwidth,
or at least a bandwidth substantially larger than f
i
, then
the total noise contribution of the external drive circuit
would be:
V
n
= n
i
p / 2 • f
i
The total system noise level can then be estimated as
the square root of the sum of (V
n
2
) and the square of the
LTC2451 noise floor (~2µV
2
).
APPLICATIONS INFORMATION