link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 link to page 5 Data SheetAD7291SPECIFICATIONS VDD = 2.8 V to 3.6 V; VDRIVE = 1.65 V to 3.6 V; fSCL = 400 kHz, fast SCLK mode; VREF = 2.5 V internal/external; TA = −40°C to +125°C, unless otherwise noted. Table 2. ParameterMinTypMaxUnit1Test Conditions/Comments DYNAMIC PERFORMANCE fIN = 1 kHz sine wave Signal-to-Noise Ratio (SNR)2 70 71 dB Signal-to-Noise (+ Distortion) Ratio (SINAD)2 70 71 dB Total Harmonic Distortion (THD)2 −84 −78 dB Spurious-Free Dynamic Range (SFDR) −85 −80 dB Intermodulation Distortion (IMD) fA = 5.4 kHz, fB = 4.6 kHz Second-Order Terms −88 dB Third-Order Terms −88 dB Channel-to-Channel Isolation −100 dB fIN = 10 kHz Full Power Bandwidth3 30 MHz At 3 dB 10 MHz At 0.1 dB DC ACCURACY Resolution 12 Bits Integral Nonlinearity (INL)2 ±0.5 ±1 LSB Differential Nonlinearity (DNL)2 ±0.5 ±0.99 LSB Guaranteed no missed codes to 12 bits Offset Error2 ±2 ±4.5 LSB Offset Error Matching2 ±2.5 ±4.5 LSB Offset Temperature Drift 4 ppm/°C Gain Error2 ±1 ±4 LSB Gain Error Matching2 ±1 ±2.5 LSB Gain Temperature Drift 0.5 ppm/°C ANALOG INPUT Input Voltage Ranges 0 VREF V DC Leakage Current ±0.01 ±1 µA Input Capacitance3 34 pF When in track 8 pF When in hold REFERENCE INPUT/OUTPUT Reference Output Voltage4 2.4925 2.5 2.5075 V ±0.3% maximum at 25°C Long-Term Stability 150 ppm For 1000 hours Output Voltage Hysteresis 50 ppm Reference Input Voltage Range5 1 2.5 V DC Leakage Current ±0.01 ±1 µA External reference applied to Pin VREF VREF Output Impedance 1 Ω Reference Temperature Coefficient 12 35 ppm/°C VREF Noise3 60 µV rms Bandwidth = 10 MHz LOGIC INPUTS (SDA, SCL) Input High Voltage, VINH 0.7 × VDRIVE V Input Low Voltage, VINL 0.3 × VDRIVE V Input Current, IIN ±0.01 ±1 µA VIN = 0 V or VDRIVE Input Capacitance, C 3 IN 6 pF Input Hysteresis, VHYST 0.1 × VDRIVE V LOGIC OUTPUTS Output High Voltage, VOH VDRIVE − 0.3 V VDRIVE < 1.8 VDRIVE − 0.2 V VDRIVE ≥ 1.8 Output Low Voltage, VOL 0.4 V ISINK = 3 mA 0.6 V ISINK = 6 mA Rev. C | Page 3 of 28 Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS REVISION HISTORY SPECIFICATIONS I2C TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY CIRCUIT INFORMATION CONVERTER OPERATION ANALOG INPUT ADC TRANSFER FUNCTION TEMPERATURE SENSOR OPERATION TEMPERATURE SENSOR AVERAGING Temperature Value Format VDRIVE THE INTERNAL OR EXTERNAL REFERENCE RESET INTERNAL REGISTER STRUCTURE ADDRESS POINTER REGISTER COMMAND REGISTER (0x00) Sample Delay and Bit Trial Delay VOLTAGE CONVERSION RESULT REGISTER (0x01) Temperature Value Format TSENSE CONVERSION RESULT REGISTER (0x02) TSENSE AVERAGE RESULT REGISTER (0X03) LIMIT REGISTERS (0X04 TO 0X1E) DATAHIGH Register DATALOW Register HYSTERESIS REGISTER ALERT STATUS REGISTER A AND ALERT STATUS REGISTER B (0x1F AND 0x20) I2C INTERFACE SERIAL BUS ADDRESS BYTE GENERAL I2C TIMING WRITING TO THE AD7291 WRITING TWO BYTES OF DATA TO A 16-BIT REGISTER WRITING TO MULTIPLE REGISTERS READING DATA FROM THE AD7291 READING TWO BYTES OF DATA FROM A 16-BIT REGISTER MODES OF OPERATION COMMAND MODE AUTOCYCLE MODE OUTLINE DIMENSIONS ORDERING GUIDE