Datasheet

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ADS1218
SBAS187C – SEPTEMBER 2001 – REVISED SEPTEMBER 2005
ELECTRICAL CHARACTERISTICS: AV
DD
= 3V (continued)
All specifications T
MIN
to T
MAX
, AV
DD
= +3V, DV
DD
= +2.7V to 5.25V, f
MOD
= 19.2kHz, f
OSC
= 2.4576MHz, PGA = 1, Buffer On,
R
DAC
= 75k Ω , V
REF
≡ (REF IN+) – (REF IN–) = +1.25V, and f
DATA
= 10Hz, unless otherwise specified.
ADS1218
PARAMETER CONDITIONS MIN TYP MAX UNIT
ON-CHIP VOLTAGE REFERENCE
Output Voltage REF HI = 0 at +25°C 1.245 1.25 1.255 V
Short-Circuit Current Source 3 mA
Short-Circuit Current Sink 50 µA
Short-Circuit Duration Sink or Source Indefinite
Drift 5 ppm/°C
Noise BW = 0.1Hz to 100Hz 10 µV
PP
Output Impedance Sourcing 100µA 3 Ω
Startup Time 50 µs
IDAC
Full-Scale Output Current R
DAC
= 75k Ω , Range = 1 0.5 mA
R
DAC
= 75k Ω , Range = 2 1 mA
R
DAC
= 75k Ω , Range = 3 2 mA
R
DAC
= 15k Ω , Range = 3 20 mA
Maximum Short-Circuit Current Duration R
DAC
= 10k Ω Indefinite
R
DAC
= 0 Ω 10 Minutes
Monotonicity R
DAC
= 75k Ω 8 Bits
Compliance Voltage 0 AV
DD
– 1 V
Output Impedance See Typical Characteristics
PSRR V
OUT
= AV
DD
/2 600 ppm/V
Absolute Error Individual IDAC 5 %
Absolute Drift Individual IDAC 75 ppm/°C
Mismatch Error Between IDACs, Same Range and Code 0.25 %
Mismatch Drift Between IDACs, Same Range and Code 15 ppm/°C
POWER-SUPPLY REQUIREMENTS
Power-Supply Voltage AV
DD
2.7 3.3 V
Analog Current (I
ADC
+ I
VREF
+ I
DAC
) PDWN = 0, or SLEEP 1 nA
ADC Current (I
ADC
) PGA = 1, Buffer Off 160 250 µA
PGA = 128, Buffer Off 450 700 µA
PGA = 1, Buffer On 230 325 µA
PGA = 128, Buffer On 850 1325 µA
V
REF
Current (I
VREF
) 250 375 µA
I
DAC
Current (I
DAC
) Excludes Load Current 480 675 µA
Digital Current Normal Mode, DV
DD
= 3V 90 200 µA
SLEEP Mode, DV
DD
= 3V 75 µA
Read Data Continuous Mode, DV
DD
= 3V 113 µA
PDWN = 0 1 nA
PGA = 1, Buffer Off, REFEN = 0,
Power Dissipation 0.8 1.4 mW
I
DACS
Off, DV
DD
= 3V
TEMPERATURE RANGE
Operating –40 +85 °C
Storage –60 +100 °C
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