link to page 17 link to page 18 link to page 17 link to page 18 link to page 17 link to page 18 link to page 17 link to page 18 link to page 17 link to page 18 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 link to page 7 Data SheetAD7715AD7715-3 AVDD = 3 V, DVDD = 3 V, REF IN (+) = 1.25 V; REF IN(−) = AGND; fCLK IN = 2.4576 MHz, unless otherwise noted. All specifications TMIN to TMAX, unless otherwise noted. Table 2. Parameter1 MinTypMaxUnitConditions/Comments STATIC PERFORMANCE No Missing Codes 16 Bits Guaranteed by design; filter notch ≤ 60 Hz Output Noise See Table 18 to Table 22 Depends on filter cutoffs and selected gain Integral Nonlinearity ±0.0015 % of FSR Filter notch ≤ 60 Hz Unipolar Offset Error2 See Table 15 to Table 22 Unipolar Offset Drift3 0.2 μV/°C Bipolar Zero Error2 See Table 15 to Table 22 Bipolar Zero Drift3 0.2 μV/°C Positive Full-Scale Error2, 4 See Table 15 to Table 22 Full-Scale Drift3, 5 0.2 μV/°C Gain Error2, 6 See Table 15 to Table 22 Gain Drift3, 7 0.2 ppm of FSR/°C Bipolar Negative Full-Scale Error2 ±0.003 % of FSR Typically ±0.0004% Bipolar Negative Full-Scale Drift3 1 μV/°C For gains of 1 and 2 0.6 μV/°C For gains of 32 and 128 ANALOG INPUTS/REFERENCE INPUTS Specifications for AIN and REF IN unless noted Input Common-Mode Rejection 90 dB At dc; tpically 102 dB (CMR) Normal-Mode 50 Hz Rejection8 98 dB For filter notches of 25 Hz, 50 Hz, ±0.02 × fNOTCH Normal-Mode 60 Hz Rejection8 98 dB For filter notches of 20 Hz, 60 Hz, ±0.02 × fNOTCH Common-Mode 50 Hz Rejection8 150 dB For filter notches of 25 Hz, 50 Hz, ±0.02 × fNOTCH Common-Mode 60 Hz Rejection8 150 dB For filter notches of 20 Hz, 60 Hz, ±0.02 × fNOTCH Common-Mode Voltage Range9 AGND AVDD V AIN for BUF bit of setup register = 0 and REF IN Absolute AIN/REF IN Voltage8 AGND − 0.03 AVDD + 0.03 V AIN for BUF bit of setup register = 0 and REF IN Absolute/Common-Mode AIN AGND + 0.05 AVDD − 1.5 V BUF bit of setup register = 1 Voltage9 AIN DC Input Current8 1 nA AIN Sampling Capacitance8 10 pF AIN Differential Voltage Range10 0 to +VREF/GAIN11 nom Unipolar input range (B/U bit of setup register = 1) ±VREF/GAIN nom Bipolar input range (B/U bit of setup register = 0) AIN Input Sampling Rate, fS GAIN × fCLK IN/64 For gains of 1 and 2 fCLK IN/8 For gains of 32 and 128 REF IN(+) − REF IN(−) Voltage 1.25 V nom ±1% for specified performance; functional with lower VREF REF IN Input Sampling Rate, fS fCLK IN/64 LOGIC INPUTS Input Current ±10 μA All Inputs Except MCLK IN VINL, Input Low Voltage 0.8 V VINH, Input High Voltage 2.0 V MCLK IN Only VINL, Input Low Voltage 0.4 V VINH, Input High Voltage 2.5 V Rev. E | Page 5 of 40 Document Outline FEATURES FUNCTIONAL BLOCK DIAGRAM GENERAL DESCRIPTION PRODUCT HIGHLIGHTS TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS AD7715-5 AD7715-3 TIMING CHARACTERISTICS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TERMINOLOGY ON-CHIP REGISTERS COMMUNICATIONS REGISTER (RS1, RS0 = 0, 0) SETUP REGISTER (RS1, RS0 = 0, 1); POWER ON/RESET STATUS: 28 HEX TEST REGISTER (RS1, RS0 = 1, 0) DATA REGISTER (RS1, RS0 = 1, 1) OUTPUT NOISE AD7715-5 AD7715-3 CALIBRATION SEQUENCES CIRCUIT DESCRIPTION ANALOG INPUT Analog Input Ranges Input Sample Rate Bipolar/Unipolar Inputs REFERENCE INPUT DIGITAL FILTERING Filter Characteristics Post-Filtering ANALOG FILTERING CALIBRATION Self-Calibration System Calibration Span and Offset Limits Power-Up and Calibration USING THE AD7715 CLOCKING AND OSCILLATOR CIRCUIT SYSTEM SYNCHRONIZATION RESET INPUT STANDBY MODE ACCURACY DRIFT CONSIDERATIONS POWER SUPPLIES Supply Current Grounding and Layout Evaluating the AD7715 Performance DIGITAL INTERFACE CONFIGURING THE AD7715 MICROCONTROLLER/MICROPROCESSOR INTERFACING AD7715 TO 68HC11 INTERFACE AD7715 TO 8XC51 INTERFACE AD7715 TO ADSP-2184N/ADSP-2185N/ ADSP-2186N/ADSP-2187N/ADSP-2188N/ ADSP-2189N INTERFACE CODE FOR SETTING UP THE AD7715 C CODE FOR INTERFACING AD7715 TO 68HC11 APPLICATIONS INFORMATION PRESSURE MEASUREMENT TEMPERATURE MEASUREMENT SMART TRANSMITTERS OUTLINE DIMENSIONS ORDERING GUIDE