LTC2453

12

2453f

from high frequency signals, and as such provides

simple antialiasing and input noise reduction.

3) Switching transients generated by the ADC are attenu-

ated before they go back to the signal source.

helping reduce reflections back to the signal source.

during an outside-the-rails fault condition.

to the point that significant measurement errors exist.

product too much may unacceptably attenuate the signal

at frequencies of interest.

a high-quality 0.1

capacitor should be located as close as possible to the

by this circuit path, as well as the path length, should be

minimized.

In the case of a 2-wire sensor that is not remotely

resistors in the ADC input line as well as in the sensor

Figure 10. Measured INL vs Input Voltage,

ground return line, which should be tied to the ADC GND

pin using a star connection topology.

Figure 10 shows the measured LTC2453 INL vs Input

The input current is zero when the ADC is either in sleep

or I/O modes. Thus, if the time constant of the input RC

circuit

longer than the time periods between actual conversions,

then one can consider the input current to be reduced

correspondingly.

These considerations need to be balanced out by the input

signal bandwidth. The 3dB bandwidth ≈ 1/(2

for the user’s specific application, an alternate strategy is to

this configuration corresponds to a low impedance sensor

directly connected to the ADC through minimum length

traces. Actual applications include current measurements

through low value sense resistors, temperature measure-

ments, low impedance voltage source monitoring, and so

responding to a minimum sized layout pad and a minimum

width input trace of about 1 inch length.

Figure 11. Measured INL vs Input Voltage,

APPLICATIONS INFORMATION

DIFFERENTIAL INPUT VOLTAGE (V)

–5

2

6

10

3

2453 F10

–2

–6

0

4

8

–4

–8

–10

–3

–4

–1

–2

12

4

0

5

DIFFERENTIAL INPUT VOLTAGE (V)

–5

2

6

10

3

2453 F11

–2

–6

0

4

8

–4

–8

–10

–3

–4

–1

–2

12

4

0

5