ADS1271

SBAS306F − NOVEMBER 2004 − REVISED OCTOBER 2007

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3

ELECTRICAL CHARACTERISTICS

All specifications at TA = −40°C to +105°C, AVDD = +5V, DVDD = +1.8V, fCLK = 27MHz, VREFP = 2.5V, and VREFN = 0V, unless otherwise noted.

Specified values for ADS1271 and ADS1271B (high-grade version) are the same, except where shown in BOLDFACE type.

ADS1271

ADS1271B

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

MIN

TYP

MAX

UNITS

Analog Inputs

Full-scale input voltage (FSR(1))

VIN = (AINP – AINN)

±VREF

±VREF

V

Absolute input voltage

AINP or AINN to AGND

AGND – 0.1

AVDD + 0.1

AGND – 0.1

AVDD + 0.1

V

Common-mode input voltage

VCM = (AINP + AINN)/2

2.5

2.5

V

Differential

High-Speed mode

16.4

16.4

k

Ω

Differential

input

impedance

High-Resolution mode

16.4

16.4

k

Ω

input

impedance

Low-Power mode

32.8

32.8

k

Ω

DC Performance

Resolution

No missing codes

24

24

Bits

Data rate

High-Speed mode

105,469

105,469

SPS

Data rate

(fDATA)

High-Resolution mode

52,734

52,734

SPS

(fDATA)

Low-Power mode

52,734

52,734

SPS

Integral nonlinearity (INL)

Differential input,

VCM = 2.5V

± 0.0006

± 0.0015

± 0.0006

± 0.0015 %FSR(1)

Offset error

High-Speed mode

Without calibration

0.150

1

0.150

1

mV

Offset error

With calibration

On the level of the noise

Offset drift

1.8

1.8

µV/_C

Gain error

0.1

0.5

0.1

0.5

%FSR(1)

Gain error drift

2

2

ppm/

°C

High-Speed mode

Shorted input

9.0

20

9.0

16

µV, rms

Noise

High-Resolution mode

6.5

6.5

12

µV, rms

Noise

Low-Power mode

9.0

9.0

16

µV, rms

Common-mode rejection

fCM = 60Hz

90

100

95

110

dB

Power-supply

AVDD

f = 60Hz

80

80

dB

Power-supply

rejection

DVDD

f = 60Hz

80

80

dB

AC Performance

Signal-to-noise

(2)

High-Speed mode

99

106

101

106

dB

Signal-to-noise

ratio (SNR) (2)

(unweighted)

High-Resolution mode

109

103

109

dB

ratio (SNR)

(unweighted)

Low-Power mode

106

101

106

dB

Total harmonic distortion (THD)(3)

VIN = 1kHz, −0.5dBFS

−105

−95

−108

−100

dB

Spurious-free dynamic range

−108

−109

dB

Passband ripple

±0.005

±0.005

dB

Passband

0.453 fDATA

0.453fDATA

Hz

−3dB Bandwidth

0.49 fDATA

0.49 fDATA

Hz

Stop band attenuation

100

100

dB

High-Speed mode

0.547fDATA

63.453 fDATA

0.547 fDATA

63.453 fDATA

Hz

Stop band

High-Resolution mode

0.547fDATA

127.453 fDATA

0.547 fDATA

127.453fDATA

Hz

Stop band

Low-Power mode

0.547fDATA

63.453 fDATA

0.547 fDATA

63.453 fDATA

Hz

Group delay

High-Speed and

Low-Power modes

38/fDATA

38/fDATA

s

Group delay

High-Resolution mode

39/fDATA

39/fDATA

s

Settling time

(latency)

High-Speed and

Low-Power modes

Complete settling

76/fDATA

76/fDATA

s

(latency)

High-Resolution mode

Complete settling

78/fDATA

78/fDATA

s

(1) FSR = full-scale range = 2VREF.

(2) Minimum SNR is ensured by the limit of the DC noise specification.

(3) THD includes the first nine harmonics of the input signal.

(4) MODE and FORMAT pins excluded.

(5) See the text for more details on SCLK.