link to page 10 Data SheetAD7768-1SPECIFICATIONS AVDD1 = 4.5 V to 5.5 V, AVDD2 = 2.0 V to 5.5 V, IOVDD = 1.7 V to 3.6 V, DGND = 0 V, AVSS = 0 V, REF+ = 4.096 V, REF− = 0 V, MCLK = 16.384 MHz, 50:50 duty cycle, analog input precharge buffers on, reference precharge on, the filter type is a low ripple FIR filter, and TA = TMIN to TMAX, unless otherwise noted. Table 1. ParameterTest Conditions/CommentsMinTypMaxUnit ADC SPEED AND CODING ODR1 Fast sinc5 8 1024 kSPS Fast low ripple FIR 8 256 kSPS Fast sinc3 0.05 256 kSPS Median sinc5 4 512 kSPS Median low ripple FIR 4 128 kSPS Median sinc3 0.025 128 kSPS Low power sinc5 1 128 kSPS Low power low ripple FIR 1 32 kSPS Low power sinc3 0.0125 32 kSPS Data Output Coding 24-bit twos complement data, followed by eight status bits (if enabled), followed by eight cyclic redundancy check (CRC) bits (if enabled) DYNAMIC PERFORMANCE Fast Mode Decimation by 32, 256 kHz ODR Dynamic Range Shorted inputs, sinc5 filter 110 111.5 dB Shorted inputs, low ripple FIR 106.5 108.5 dB A-weighted, 1 kHz input, −60 dBFS, 115 dB decimation by 128, low ripple FIR Signal to Noise Ratio 1 kHz, −0.25 dBFS, sine input (SNR) Sinc5 filter 110.5 dB Low ripple FIR 106 107.5 dB Signal-to-Noise-and- 1 kHz, −0.25 dBFS, sine input 105 107.3 dB Distortion (SINAD) Total Harmonic 1 kHz, −0.25 dBFS, sine input −120 −112 dB Distortion (THD) Spurious-Free Dynamic 1 kHz, −0.25 dBFS, sine input 125 dBc Range (SFDR) Median Mode Decimation by 32, 128 kHz ODR Dynamic Range Shorted inputs, sinc5 filter 110 111.5 dB Shorted inputs, low ripple FIR 106.5 108.5 dB SNR 1 kHz, −0.25 dBFS, sine input Sinc5 filter 110.5 dB Low ripple FIR 106 107.5 dB SINAD 1 kHz, −0.25 dBFS, sine input 105 107.3 dB THD 1 kHz, −0.25 dBFS, sine input −120 −112 dB SFDR 1 kHz, −0.25 dBFS, sine input 125 dBc Low Power Mode Decimation by 32, 32 kHz ODR Dynamic Range Shorted inputs, sinc5 filter 110 111.5 dB Shorted inputs, low ripple FIR 106.5 108.5 dB SNR 1 kHz, −0.25 dBFS, sine input Sinc filter 111 dB Low ripple FIR 106 107.8 dB Rev. A | Page 5 of 80 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAM TABLE OF CONTENTS REVISION HISTORY GENERAL DESCRIPTION SPECIFICATIONS 3 V OPERATION TIMING SPECIFICATIONS 1.8 V TIMING SPECIFICATIONS Timing Diagrams ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS TERMINOLOGY THEORY OF OPERATION CLOCKING, SAMPLING TREE, AND POWER SCALING Power vs. Noise Performance Optimization Example of Power vs. Noise Performance Optimization Configuration A Configuration B NOISE PERFORMANCE AND RESOLUTION CORE CONVERTER ADC Core and Signal Chain Analog Inputs and Precharge Buffering VCM Output Reference Input and Buffering CLOCKING AND CLOCK SELECTION CLKSEL Pin Using the Internal Oscillator DIGITAL FILTERING Sinc5 Filter Sinc3 Filter Programming for 50 Hz, 60 Hz, and 50 Hz and 60 Hz Rejection Low Ripple FIR Filter DECIMATION RATE CONTROL ANTIALIASING FILTERING Modulator Saturation Point Modulator Unprotected Zones Modulator Chopping Frequency GETTING STARTED Method of Configuration—PINB Control Mode or SPI Control Mode Digital Filter Type and Decimation Power Mode POWER SUPPLIES Single-Supply Mode Recommended Power Supply Configuration DEVICE CONFIGURATION METHOD PINB Configuration SPI Control PIN CONTROL MODE OVERVIEW Power Mode Data Output Format Diagnostics and Status Bits Daisy-Chaining—PINB Control Mode Only SPI CONTROL OVERVIEW SPI CONTROL MODE MCLK Source and MCLK Division Power-Down Mode Standby Mode SPI Synchronization Offset Calibration Gain Calibration Reset over SPI Control Interface Resume from Shutdown GPIO and STARTB Functions SPI Mode Diagnostic Features Reference Detection Clock Qualification CRC on SPI Transaction Flags for Detection of Illegal Register Write CRC Checks POR Monitor MCLK Counter Product Identification (ID) Number DIGITAL INTERFACE SPI Reading and Writing SPI Control Interface Error Handling CRC Check on Serial Interface Conversion Read Modes Single-Conversion Read Mode Continuous Read Mode Exiting Continuous Read Mode DATA CONVERSION MODES Continuous Conversion Mode One Shot Conversion Mode Single-Conversion Mode Duty Cycled Conversion Mode SYNCHRONIZATION OF MULTIPLE AD7768-1 DEVICES ADDITIONAL FUNCTIONALITY OF THE AD7768-1 Reset Status Header Diagnostics APPLICATIONS INFORMATION ANALOG INPUT RECOMMENDATIONS Recommended Driver Amplifiers ANTIALIASING FILTER DESIGN CONSIDERATIONS RECOMMENDED INTERFACE Initializing the Recommended Interface Recommended Interface for Reading Data Resynchronization of the Recommended Interface PROGRAMMABLE DIGITAL FILTER Filter Coefficients Upload Sequence Example Filter Upload Filter Upload Verification ELECTROMAGNETIC COMPATIBILITY (EMC) TESTING Radiated Immunity Radiated Emissions Electrical Fast Transients (EFTs) AD7768-1 SUBSYSTEM LAYOUT REGISTER SUMMARY REGISTER DETAILS COMPONENT TYPE REGISTER UNIQUE PRODUCT ID REGISTERS DEVICE GRADE AND REVISION REGISTER USER SCRATCHPAD REGISTER DEVICE VENDOR ID REGISTERS INTERFACE FORMAT CONTROL REGISTER POWER AND CLOCK CONTROL REGISTER ANALOG BUFFER CONTROL REGISTER VCM CONTROL REGISTER CONVERSION SOURCE SELECT AND MODE CONTROL REGISTER DIGITAL FILTER AND DECIMATION CONTROL REGISTER SINC3 DECIMATION RATE (MSB REGISTER) SINC3 DECIMATION RATE (LSB REGISTER) PERIODIC CONVERSION RATE CONTROL REGISTER SYNCHRONIZATION MODES AND RESET TRIGGERING REGISTER GPIO PORT CONTROL REGISTER GPIO OUTPUT CONTROL REGISTER GPIO INPUT READ REGISTER OFFSET CALIBRATION MSB REGISTER OFFSET CALIBRATION MID REGISTER OFFSET CALIBRATION LSB REGISTER GAIN CALIBRATION MSB REGISTER GAIN CALIBRATION MID REGISTER GAIN CALIBRATION LSB REGISTER SPI INTERFACE DIAGNOSTIC CONTROL REGISTER ADC DIAGNOSTIC FEATURE CONTROL REGISTER DIGITAL DIAGNOSTIC FEATURE CONTROL REGISTER CONVERSION RESULT REGISTER DEVICE ERROR FLAGS MASTER REGISTER SPI INTERFACE ERROR REGISTER ADC DIAGNOSTICS OUTPUT REGISTER DIGITAL DIAGNOSTICS OUTPUT REGISTER MCLK DIAGNOSTIC OUTPUT REGISTER COEFFICIENT CONTROL REGISTER COEFFICIENT DATA REGISTER ACCESS KEY REGISTER OUTLINE DIMENSIONS ORDERING GUIDE