Datasheet

ADS1259
www.ti.com SBAS424D –JUNE 2009– REVISED AUGUST 2011
ELECTRICAL CHARACTERISTICS
Minimum/maximum specifications are at T
A
= –40°C to +105°C. Typical specifications are at T
A
= +25°C, AVDD = +2.5V, AVSS = –2.5V,
DVDD = +3.3V, f
CLK
= 7.3728MHz, V
REF
= 2.5V, and f
DATA
= 60SPS, unless otherwise noted.
ADS1259 ADS1259B
PARAMETER TEST CONDITIONS MIN TYP MAX MIN TYP MAX UNIT
ANALOG INPUTS
Full-scale input voltage range (FSR) V
IN
= (AINP – AINN) ±V
REF
±V
REF
V
Absolute input voltage
AVSS – 0.1 AVDD + 0.1 AVSS – 0.1 AVDD + 0.1 V
(AINP, AINN to DGND)
Differential input impedance 120 120 kΩ
Common-mode input impedance 500 500 kΩ
SYSTEM PERFORMANCE
Resolution No missing codes 24 24 Bits
Data rate (f
DATA
) 10 14400 10 14400 SPS
(1)
Integral nonlinearity Best fit method ±0.0003 ±0.001 ±0.00004
(2)
±0.0003 %FSR
Offset error ±40 ±250 ±40 ±250 μV
Offset error after calibration
(3)
±1 ±1 μV
Offset drift
(4)
T
A
= –40°C to +105°C 0.05 0.25 0.05 0.25 μV/°C
Gain error
(5)
±0.05 ±0.5 ±0.05 ±0.5 %
Gain error after calibration
(3)
±0.0002 ±0.0002 %
Gain drift
(4)
T
A
= –40°C to +105°C 0.5 2.5 0.5 2.5 ppm/°C
Normal mode rejection See Figure 42
Common-mode rejection 60Hz, ac
(6)
100 120 100 120 dB
Noise See Table 1 0.7 0.7 μV
AVDD, AVSS power-supply
60Hz, ac
(6)
85 95 85 95 dB
rejection
DVDD power-supply rejection 60Hz, ac
(6)
85 110 85 110 dB
OUT-OF-RANGE DETECTION
Level ±105 ±105 %FSR
Threshold
(7)
Accuracy ±0.5 ±0.5 %FSR
VOLTAGE REFERENCE INPUTS
V
REF
= (VREFP – AVDD – AVSS + AVDD – AVSS +
Reference input range (V
REF
) 0.5 2.5 0.5 2.5 V
VREFN) 200mV 200mV
Negative reference absolute input AVSS – AVSS –
VREFP – 0.5 VREFP – 0.5 V
(VREFN to DGND) 100mV 100mV
Positive reference absolute input
VREFN + 0.5 AVDD + 100mV VREFN + 0.5 AVDD + 100mV V
(VREFP to DGND)
200nA + 200nA +
Average reference input current
(8)
60nA/V 60nA/V
Average reference input current drift Internal or external clock 0.2 0.2 nA/°C
INTERNAL VOLTAGE REFERENCE
V
REFOUT
= (REFOUT –
Reference output voltage 2.5 2.5 V
AVSS)
Accuracy T
A
= +25°C ±0.4 ±0.2 %
T
A
= –40°C to +105°C 10 40 4 12 ppm/°C
Temperature drift
(4)
T
A
= 0°C to +85°C 2 5 ppm/°C
Drive current sink and source –10 10 –10 10 mA
(9)
Load regulation 10 10 μV/mA
Turn-on settling time
(10)
±0.001% settling 1 1 s
Long-term stability 0 to 1000 hours 70 70 ppm/1000hr
Thermal hysteresis
(11)
30 30 ppm
(1) SPS = samples per second.
(2) Shaded cells indicate improved specifications of the ADS1259B.
(3) Calibration accuracy is on the level of noise (signal and ADC), reduced by the effect of 16 reading averaging.
(4) Reference drift specified by design and final production test. Drift calculated over the specified temperature range using box method.
(5) Excludes internal reference error.
(6) f
DATA
= 14.4kSPS. Placing a notch of the digital filter at 60Hz (setting f
DATA
= 10SPS or 60SPS) further improves the common-mode
rejection and power-supply rejection of this input frequency.
(7) Absolute input voltage range for out-of-range specification: AVSS + 150mV ≤ AINP or AINN ≤ AVDD – 150mV.
(8) Over the range: AVSS ≤ VREFP or VREFN ≤ AVDD. For reference voltage exceeding AVDD or AVSS, input current = 150nA/10mV.
(9) Limit the reference output current to ±10mA.
(10) C
REFOUT
= 1μF, C
REFIN
= 1μF.
(11) See the Thermal Hysteresis section.
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