Datasheet

(V )(Gain)
IN
2
AVSS 0.1V+ +
AVDD 0.1V- -
(V )(Gain)
IN
2
ADS1146
ADS1147
ADS1148
www.ti.com SBAS453F –JULY 2009–REVISED APRIL 2012
ELECTRICAL CHARACTERISTICS
Minimum/maximum specifications apply from –40°C to +105°C. Typical specifications are at +25°C. All specifications at
AVDD = +5V, DVDD = +3.3V, AVSS = DGND = 0V, V
REF
= +2.048V, and oscillator frequency = 4.096MHz, unless otherwise
noted.
ADS1146, ADS1147, ADS1148
PARAMETER CONDITIONS MIN TYP MAX UNIT
ANALOG INPUTS
Full-scale input voltage
±V
REF
/PGA
(1)
V
(V
IN
= ADCINP – ADCINN)
Common-mode input range V
Differential input current 100 pA
1, 2, 4, 8, 16, 32,
PGA gain settings
64, 128
Burnout current source 0.5, 2, or 10 μA
Bias voltage (AVDD + AVSS)/2 V
Bias voltage output impedance 400 Ω
SYSTEM PERFORMANCE
Resolution No missing codes 16 Bits
5, 10, 20, 40, 80,
Data rate 160, 320, 640, SPS
1000, 2000
Integral nonlinearity (INL) Differential input, end point fit, PGA = 1 ±0.5 ±1 LSB
Offset error After calibration 1 LSB
PGA = 1 100 nV/°C
Offset drift
PGA = 128 15 nV/°C
Gain error Excluding V
REF
errors ±0.5 %
PGA = 1, excludes V
REF
drift 1 ppm/°C
Gain drift
PGA = 128, excludes V
REF
drift –3.5 ppm/°C
ADC conversion time Single-cycle settling See Table 12
Noise See Table 1 and Table 2
Normal-mode rejection See Table 5
At dc, PGA = 1 90 dB
Common-mode rejection
At dc, PGA = 32 100 dB
Power-supply rejection AVDD, DVDD at dc 100 dB
VOLTAGE REFERENCE INPUT
Voltage reference input (AVDD –
0.5 V
(V
REF
= V
REFP
– V
REFN
) AVSS) – 1
Negative reference input (REFN) AVSS – 0.1 REFP – 0.5 V
Positive reference input (REFP) REFN + 0.5 AVDD + 0.1 V
Reference input current 30 nA
ON-CHIP VOLTAGE REFERENCE
Output voltage 2.038 2.048 2.058 V
Output current
(2)
±10 mA
Load regulation 50 μV/mA
Drift
(3)
T
A
= –40°C to +105°C 20 50 ppm/°C
Startup time See Table 6 μs
(1) For V
REF
> 2.7V, the analog input differential voltage should not exceed 2.7V/PGA
(2) Do not exceed this loading on the internal voltage reference.
(3) Specified by the combination of design and final production test.
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