REV. 0

–2–

AD7738–SPECIFICATIONS

Parameter

Min

Typ

Max

Unit

Test Conditions/Comment

ADC PERFORMANCE—

CHOPPING ENABLED

Conversion Time Rate

372

12190

Hz

Configure via Conversion Time Register

No Missing Codes

1

24

Bits

FW

≥ 6 (Conversion Time ≥ 165 µs)

See Typical Performance Characteristics

Output Noise

See Table I

Resolution

See Tables II and III

Integral Nonlinearity (INL)

±0.0015

% of FSR

AIN Range =

±2.5 V

±0.0015

% of FSR

AIN Range =

±1.25 V

Offset Error (Unipolar, Bipolar)

2

±10

µV

Before Calibration

Offset Drift vs. Temperature

1

±280

nV/

°C

Gain Error

2

±0.2

%

Before Calibration

Gain Drift vs. Temperature

1

±2.5

ppm of FS/ C

Positive Full-Scale Error

2

±0.2

% of FSR

Before Calibration

Positive Full-Scale Drift vs. Temperature

1

±2.5

ppm of FS/ C

Bipolar Negative Full-Scale Error

3

±0.0030

% of FSR

After Calibration

3

Common-Mode Rejection

80

100

dB

At DC, AIN = 1 V

Power Supply Rejection

70

80

dB

At DC, AIN = 1 V

ADC PERFORMANCE—

CHOPPING DISABLED

Conversion Time Rate

737

15437

Hz

Configure via Conversion Time Register

No Missing Codes

1

24

Bits

FW

≥ 8 (Conversion Time ≥ 117 µs)

See Typical Perfomance Charateristics

Output Noise

See Table IV

Resolution

See Tables V and VI

Integral Nonlinearity (INL)

±0.0015

% of FSR

Offset Error (Unipolar, Bipolar)

4

± 1mV

Before Calibration

Offset Drift vs. Temperature

±1.5

µV/ C

Gain Error

2

±0.2

%

Before Calibration

Gain Drift vs. Temperature

±2.5

ppm of FS/ C

Positive Full-Scale Error

2

±0.2

% of FSR

Before Calibration

Positive Full-Scale Drift vs. Temperature

±2.5

ppm of FS/ C

Bipolar Negative Full-Scale Error

3

±0.0030

% of FSR

After Calibration

3

Common-Mode Rejection

75

dB

At DC, AIN = 1 V

Power Supply Rejection

65

dB

At DC, AIN = 1 V

ANALOG INPUTS

Analog Input Voltage Ranges

1, 5

±2.5 V Range

–2.9

±2.5

+2.9

V

+2.5 V Range

0

0 to 2.5

2.9

V

±1.25 V Range

–1.45

±1.25

+1.45

V

+1.25 V Range

0

0 to 1.25 1.45

V

±0.625 V Range

–725

±625

+725

mV

+0.625 V Range

0

0 to 625

725

mV

AIN, AINCOM Common-Mode Voltage

1

0.2

AIN, AINCOM Input Current

6

200

nA

Only One Channel, Chop Disabled

AIN to MUXOUT On Resistance

1

200

Ω

REFERENCE INPUT

REFIN(+) to REFIN(–) Voltage

1, 7

2.475

2.5

2.525

V

NOREF Trigger Voltage

0.5

V

NOREF Bit in Channel Status Register

REFIN(+), REFIN(–)

Common-Mode Voltage

1

V

Reference Input Current

8

400

µA

Full Scale Calibration Limit

+1.05

FS V

Zero Scale Calibration Limit

–1.05

FS

V

Input Span

0.8

FS

2.1

FS

V

5%,

REFIN(+) = 2.5 V, REFIN(–) = 0 V, AINCOM = 2.5 V, MUXOUT(+) = ADCIN(+), MUXOUT(–) = ADCIN(–), Internal Buffer ON, AIN Range =

1.25 V,