Datasheet AD7708, AD7718 (Analog Devices) - 6

AD7708/AD7718 AD7708 SPECIFICATIONS1 (AVDD = 2.7 V to 3.6 V or 4.75 V to 5.25 V, DVDD = 2.7 V to 3.6 V or 4.75 V to 5.25 V, REFIN(+) = 2.5 V; REFIN(–) = AGND; AGND = DGND = 0 V; XTAL1/XTAL2 = 32.768 kHz Crystal Input Buffers Enabled. All specifications TMIN to TMAX unless otherwise noted.) Parameter B Grade Unit Test Conditions AD7708 (CHOP DISABLED)
Output Update Rate 16.06 Hz min CHOP = 1 1.365 kHz max No Missing Codes2 16 Bits min Resolution 13 Bits p-p ±20 mV Range, SF Word = 69 16 Bits p-p ±2.56 V Range, SF Word = 69 Output Noise and Update Rates See Tables in ADC Description Integral Nonlinearity ±15 ppm of FSR max 2ppm Typical Offset Error3 ±0.65 LSB typ Following a Self-Calibration Offset Error Drift vs. Temp4 ±200 nV/°C typ Full-Scale Error3 ±0.75 LSB typ Gain Drift vs. Temp4 ±0.5 ppm/°C typ Negative Full-Scale Error ±0.003 % FSR 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 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 Bias Current Drift ±5 pA/°C typ AINCOM Input Current NEGBUF = 0 DC Input Current2 ±125 nA/V typ ±2.56 V Range 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 100 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 Hz 100 dB typ 50 Hz ± 1 Hz, SF Word = 82 @ 60 Hz 100 dB typ 60 Hz ± 1 Hz, SF Word = 68 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 Current 0.5 µA/V typ Reference DC Input Current Drift ±0.1 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 100 dB typ Analog Input = 1 V. Input Range = ±2.56 V @ 50 Hz 100 dB typ @ 60 Hz 100 dB typ –6– REV. 0