Datasheet
ADS1291
ADS1292
ADS1292R
www.ti.com
SBAS502B –DECEMBER 2011–REVISED SEPTEMBER 2012
ELECTRICAL CHARACTERISTICS (continued)
Minimum and maximum specifications apply from –40°C to +85°C. Typical specifications are at +25°C. All specifications are
at DVDD = 1.8 V, AVDD – AVSS = 3 V
(1)
, V
REF
= 2.42 V, external f
CLK
= 512 kHz, data rate = 500 SPS, C
FILTER
= 4.7 nF
(2)
,
and gain = 6, unless otherwise noted.
ADS1291, ADS1292, ADS1292R
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
INTERNAL REFERENCE
Register bit CONFIG2.VREF_4V = 0 2.42 V
Output voltage
Register bit CONFIG2.VREF_4V = 1 4.033 V
Output current drive Available for external use 100 µA
V
REF
accuracy ±0.5 %
Internal reference drift –40°C ≤ T
A
≤ +85°C 45 ppm/°C
Settled to 0.2% with 10-µF capacitor on
Start-up time 100 ms
VREFP pin
Quiescent current consumption 20 µA
SYSTEM MONITORS
Analog supply reading error 1 %
Digital supply reading error 1 %
From power-supply ramp after power-on
32 ms
reset (POR) to DRDY low
Device wake up
From power-down mode to DRDY low 10 ms
From STANDBY mode to DRDY low 10 ms
VCAP1 settling time 1% accuracy 0.5 s
Voltage T
A
= +25°C 145 mV
Temperature sensor
reading
Coefficient 490 μV/°C
TEST SIGNAL
Signal frequency See Register Map section for settings At dc and 1 Hz Hz
Signal voltage See Register Map section for settings ±1 mV
Accuracy ±2 %
CLOCK
Internal oscillator clock frequency Nominal frequency 512 kHz
T
A
= +25°C ±0.5 %
Internal clock accuracy
–40°C ≤ T
A
≤ +85°C ±1.5 %
Internal oscillator start-up time 32 μs
Internal oscillator power consumption 30 μW
CLKSEL pin = 0, CLK_DIV = 0 485 512 562.5 kHz
External clock input frequency
CLKSEL pin = 0, CLK_DIV = 1 1.94 2.048 2.25 MHz
DIGITAL INPUT/OUTPUT
DVDD = 1.8 V to
V
IH
0.8 DVDD DVDD + 0.1 V
3.6 V
DVDD = 1.8 V to
V
IL
–0.1 0.2 DVDD V
3.6 V
DVDD = 1.7 V to
V
IH
DVDD – 0.2 V
1.8 V
Logic level DVDD = 1.7 V to
V
IL
0.2 V
1.8 V
DVDD = 1.7 V to
V
OH
I
OH
= –500 μA 0.9 DVDD V
3.6 V
DVDD = 1.7 V to
V
OL
I
OL
= +500 μA 0.1 DVDD V
3.6 V
I
IN
Input current 0 V < V
DigitalInput
< DVDD –10 +10 μA
POWER-SUPPLY REQUIREMENTS
AVDD Analog supply AVDD – AVSS 2.7 3 5.25 V
DVDD Digital supply DVDD – DGND 1.7 1.8 3.6 V
AVDD – DVDD –2.1 3.6 V
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