Datasheet AD7708, AD7718 (Analog Devices) - 7

AD7708/AD7718 Parameter B Grade Unit Test Conditions AD7708 (CHOP ENABLED
) Output Update Rate 5.4 Hz min CHOP = 1 105 Hz max 0.732 ms Increments No Missing Codes2 16 Bits min 20 Hz Update Rate Resolution 13 Bits p-p ±20 mV Range, 20 Hz Update Rate 16 Bits p-p ±2.56 V Range, 20 Hz Update Rate Output Noise and Update Rates See Tables in ADC Description Integral Nonlinearity ±15 ppm of FSR max 2 ppm Typical Offset Error3 ±3 µV typ Calibration is Accurate to ± 0.5 LSB Offset Error Drift vs. Temp4 10 nV/°C typ Full-Scale Error3 ±0.75 LSB typ Includes Positive and Negative ERRORS Gain Drift vs. Temp4 ±0.5 ppm/°C typ ANALOG INPUTS Differential Input Full-Scale Voltage ±1.024 × REFIN/GAIN V nom REFIN Refers to Both REFIN1 and REFIN2. REFIN = REFIN(+) REFIN(–) GAIN = 1 to 128 Range Matching ±2 µV typ Analog Input = 18 mV Absolute AIN Voltage Limits AGND + 100 mV V min AIN1–AIN10 and AINCOM with AVDD – 100 mV V max NEGBUF = 1 Absolute AINCOM Voltage Limits AGND – 30 mV V min NEGBUF = 0 AVDD + 30 mV V max Analog Input Current AIN1–AIN10 and AINCOM with NEGBUF = 1 DC Input Current2 ±1 nA max DC Input Current Drift ±5 pA/°C typ AINCOM Input Current NEGBUF = 0 DC Input Current2 ±125 nA/V typ DC Bias Current Drift ±2 pA/V/°C typ Normal-Mode Rejection2 @ 50 Hz 100 dB min 50 Hz ± 1 Hz, SF Word = 82 @ 60 Hz 94 dB min 60 Hz ± 1 Hz, SF Word = 68 Common-Mode Rejection @ DC 90 dB min 100 dB typ, Analog Input = 1 V, Input Range = ±2.56 V 110 dB typ on ± 20 mV Range @ 50 Hz2 100 dB min 50 Hz ± 1 Hz, 20 Hz Update Rate @ 60 Hz2 100 dB min 60 Hz ± 1 Hz, 20 Hz Update Rate REFERENCE INPUTS (REFIN1 AND REFIN2) REFIN(+) to REFIN(–) Voltage 2.5 V nom REFIN Refers to Both REFIN1 and REFIN2 REFIN(+) to REFIN(–) Range2 1 V min AVDD V max REFIN Common-Mode Range AGND – 30 mV V min AVDD + 30 mV V max Reference DC Input Current2 ±0.5 µA/V typ Reference DC Input Current Drift ±0.01 nA/V/°C typ Normal-Mode Rejection2 @ 50 Hz 100 dB min 50 Hz ± 1 Hz, SF Word = 82 @ 60 Hz 100 dB min 60 Hz ± 1 Hz, SF Word = 68 Common-Mode Rejection Input Range = ± 2.56 V @ DC 110 dB typ Analog Input = 1 V @ 50 Hz 110 dB typ 50 Hz ± 1 Hz, 20 Hz Update Rate @ 60 Hz 110 dB typ 60 Hz ± 1 Hz, 20 Hz Update Rate LOGIC INPUTS5 All Inputs Except SCLK and XTAL12 VINL, Input Low Voltage 0.8 V max DVDD = 5 V 0.4 V max DVDD = 3 V VINH, Input High Voltage 2.0 V min DVDD = 3 V or 5 V REV. 0 –7–