link to page 16 link to page 13 Data SheetAD7985SPECIFICATIONS AVDD = DVDD = 2.5 V, BVDD = 5 V, VIO = 1.8 V to 2.7 V, VREF = 4.096 V, TA = −40°C to +85°C, unless otherwise noted. Table 2. ParameterTest Conditions/CommentsMinTypMaxUnit RESOLUTION 16 Bits ANALOG INPUT Voltage Range (IN+) − (IN−) 0 VREF V Absolute Input Voltage IN+ −0.1 VREF + 0.1 V IN− −0.1 +0.1 V Leakage Current at 25°C Acquisition phase 250 nA Input Impedance See the Analog Inputs section ACCURACY No Missing Codes 16 Bits Differential Nonlinearity Error, DNL −0.99 ±0.50 +0.99 LSB1 Integral Nonlinearity Error, INL −1.50 ±0.7 +1.50 LSB1 Transition Noise 0.8 LSB1 Gain Error, T 2 MIN to TMAX −15 ±2 +15 LSB1 Gain Error Temperature Drift ±0.8 ppm/°C Zero Error, T 2 MIN to TMAX −0.99 ±0.08 +0.99 mV Zero Temperature Drift 0.55 ppm/°C Power Supply Sensitivity AVDD = 2.5 V ± 5% 90 dB3 THROUGHPUT Conversion Rate 0 2.5 MSPS Transient Response Full-scale step 100 ns AC ACCURACY Dynamic Range VREF = 4.096 V, internal reference 87.5 89 dB3 VREF = 5.0 V, external reference 89.0 90 dB3 Signal-to-Noise Ratio, SNR fIN = 20 kHz, VREF = 4.096 V, internal 87.0 88.5 dB3 reference fIN = 20 kHz, VREF = 5.0 V, external 89.0 90.0 dB3 reference Spurious-Free Dynamic Range, SFDR fIN = 20 kHz 103 dB3 Total Harmonic Distortion, THD fIN = 20 kHz, VREF = 4.096 V, internal −100 dB3 reference Signal-to-Noise-and-Distortion Ratio, fIN = 20 kHz, VREF = 4.096 V 90 dB3 SINAD SAMPLING DYNAMICS −3 dB Input Bandwidth 19 MHz Aperture Delay 0.7 ns 1 LSB means least significant bit. With the 4.096 V input range, one LSB is 62.5 µV. 2 See the Terminology section. These specifications include full temperature range variation but not the error contribution from the external reference. 3 All specifications expressed in decibels are referred to a full-scale input FSR and tested with an input signal at 0.5 dB below ful scale, unless otherwise specified. Rev. C | Page 3 of 28 Document Outline FEATURES APPLICATIONS APPLICATION DIAGRAM GENERAL DESCRIPTION REVISION HISTORY SPECIFICATIONS TIMING SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION CIRCUIT INFORMATION CONVERTER OPERATION CONVERSION MODES OF OPERATION Transfer Functions TYPICAL CONNECTION DIAGRAM ANALOG INPUTS DRIVER AMPLIFIER CHOICE VOLTAGE REFERENCE INPUT Internal Reference, REF = 4.096 V (PDREF Low) External 1.2 V Reference and Internal Buffer (PDREF High) External Reference (PDREF High, REFIN Low) Reference Decoupling POWER SUPPLY DIGITAL INTERFACE DATA READING OPTIONS Reading During Conversion, Fast Host (Turbo or Normal Mode) Split-Reading, Any Speed Host (Turbo or Normal Mode) Reading During Acquisition, Any Speed Host (Turbo or Normal Mode) /CS MODE, 3-WIRE WITHOUT BUSY INDICATOR /CS MODE, 3-WIRE WITH BUSY INDICATOR /CS MODE, 4-WIRE WITHOUT BUSY INDICATOR /CS MODE, 4-WIRE WITH BUSY INDICATOR CHAIN MODE WITHOUT BUSY INDICATOR CHAIN MODE WITH BUSY INDICATOR APPLICATIONS INFORMATION LAYOUT EVALUATING THE AD7985 PERFORMANCE OUTLINE DIMENSIONS ORDERING GUIDE