11

LTC2420

APPLICATIO S I FOR ATIO

Table 3. Typical Performance of the LTC2420 ADC When Used with the

LT1920 Instrumentation Amplifiers in Figure 9’s Differential Digitizing Circuit

PARAMETER

TOTAL (UNITS)

Differential Input Voltage Range

– 30 to 400

– 3 to 40

– 30 to 500

– 3 to 50

mV

Zero Error

–160

– 2650

– 213

– 2625

µV

Maximum Input Current

2.0

nA

Nonlinearity

±8.2

±7.4

±6.5

±6.1

ppm

Noise (Without Averaging)

1.8*

0.25*

1.5*

0.27*

Noise (Averaged 64 Readings)

0.2*

0.03*

0.19*

0.03*

Resolution (with Averaged Readings)

21

20.6

21.3

20.5

Bits

Overall Accuracy (Uncalibrated)

17.2

17.3

17.5

18.2

Bits

Common Mode Rejection Ratio

≥120

dB

Common Mode Range

2/–1.5**

2.2/–1.7**

11.5/–11**

11.7/–11.2**

V

*Input referred noise for the respective gain. **Typical values based on single lab tested sample of each amplifier.

Table 4. Typical Performance of the LTC2420 ADC When Used with the

LT1167 Instrumentation Amplifiers in Figure 9’s Differential Digitizing Circuit

PARAMETER

TOTAL (UNITS)

Differential Input Voltage Range

– 30 to 400

– 3 to 40

– 30 to 500

– 3 to 50

mV

Zero Error

–94

– 1590

– 110

– 1470

µV

Maximum Input Current

0.5

nA

Nonlinearity

±4.1

±4.4

±4.1

±3.7

ppm

Noise (Without Averaging)

1.4*

0.19*

1.5*

0.18*

Noise (Averaged 64 Readings)

0.18*

0.02*

0.19*

0.02*

Resolution (with Averaged Readings)

21.4

21.0

21.3

21.1

Bits

Overall Accuracy (Uncalibrated)

18.2

18.1

18.2

19.4

Bits

Common Mode Rejection Ratio

≥120

dB

Common Mode Range

2/–1.5**

2.2/–1.7**

11.5/–11**

11.7/–11.2**

V

*Input referred noise for the respective gain. **Typical values based on single lab tested sample of each amplifier.