Datasheet ADAS1000-3, ADAS1000-4 (Analog Devices) - 5

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Data Sheet ADAS1000-3/ADAS1000-4 SPECIFICATIONS
AVDD = 3.3 V ± 5%, IOVDD = 1.65 V to 3.6 V, AGND = DGND = 0 V, REFIN tied to REFOUT, externally supplied crystal/clock = 8.192 MHz. Decoupling for reference and supplies as noted in the Power Supply, Grounding, and Decoupling Strategy section. TA = −40°C to +85°C, unless otherwise noted. Typical specifications are mean values at TA = 25°C. For specified performance, internal ADCVDD and DVDD linear regulators have been used. They may be supplied from external regulators. ADCVDD = 1.8 V ± 5%, DVDD = 1.8 V ± 5%. Front-end gain settings: GAIN 0 = ×1.4, GAIN 1 = ×2.1, GAIN 2 = ×2.8, GAIN 3 = ×4.2.
Table 2. Parameter Min Typ Max Unit Test Conditions/Comments
ECG CHANNEL These specifications apply to the following pins: ECG1_LA, ECG2_LL, ECG3_RA, CM_IN (CE mode), EXT_RESP_xx pins when used in extend switch mode Electrode Input Range Independent of supply 0.3 1.3 2.3 V GAIN 0 (gain setting ×1.4) 0.63 1.3 1.97 V GAIN 1 (gain setting ×2.1) 0.8 1.3 1.8 V GAIN 2 (gain setting ×2.8) 0.97 1.3 1.63 V GAIN 3 (gain setting ×4.2) Input Bias Current −40 ±1 +40 nA Relates to each electrode input; over operating range; dc and ac lead-off are disabled −200 +200 nA AGND to AVDD Input Offset −7 mV Electrode/vector mode with VCM = VCM_REF GAIN 3 −7 mV GAIN 2 −15 mV GAIN 1 −22 mV GAIN 0 Input Offset Tempco1 ±2 μV/°C Input Amplifier Input 1||10 GΩ||pF At 10 Hz Impedance2 CMRR2 105 110 dB 51 kΩ imbalance, 60 Hz with ±300 mV differential dc offset; per AAMI/IEC standards; with driven leg loop closed Crosstalk1 80 dB Between channels Resolution2 19 Bits Electrode/vector mode, 2 kHz data rate, 24-bit data-word 18 Bits Electrode/vector mode, 16 kHz data rate, 24-bit data- word 16 Bits Electrode/analog lead mode, 128 kHz data rate, 16-bit data-word Integral Nonlinearity Error 30 ppm GAIN 0; all data rates Differential Nonlinearity Error 5 ppm GAIN 0 Gain2 Referred to input; (2 × VREF)/gain/(2N − 1); Applies after factory calibration. User calibration adjusts this number. GAIN 0 (×1.4) 4.9 µV/LSB At 19-bit level in 2 kHz data rate 9.81 μV/LSB At 18-bit level in 16 kHz data rate 39.24 μV/LSB At 16-bit level in 128 kHz data rate GAIN 1 (×2.1) 3.27 μV/LSB At 19-bit level in 2 kHz data rate 6.54 μV/LSB At 18-bit level in 16 kHz data rate 26.15 μV/LSB At 16-bit level in 128 kHz data rate GAIN 2 (×2.8) 2.45 μV/LSB At 19-bit level in 2 kHz data rate 4.9 μV/LSB At 18-bit level in 16 kHz data rate 19.62 μV/LSB At 16-bit level in 128 kHz data rate GAIN 3 (×4.2) 1.63 μV/LSB No factory calibration for this gain setting At 19-bit level in 2 kHz data rate 3.27 μV/LSB At 18-bit level in 16 kHz data rate 13.08 μV/LSB At 16-bit level in 128 kHz data rate Rev. B | Page 5 of 80 Document Outline FEATURES APPLICATIONS GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY FUNCTIONAL BLOCK DIAGRAM SPECIFICATIONS NOISE PERFORMANCE TIMING CHARACTERISTICS Standard Serial Interface Secondary Serial Interface (Master Interface for Customer-Based Digital Pace Algorithm) ADAS1000-4 Only ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE ESD CAUTION PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS APPLICATIONS INFORMATION OVERVIEW ECG INPUTS—ELECTRODES/LEADS ECG CHANNEL ELECTRODE/LEAD FORMATION AND INPUT STAGE CONFIGURATION Analog Lead Mode and Calculation Digital Lead Mode and Calculation Electrode Mode: Single-Ended Input Electrode Configuration Electrode Mode: Common Electrode A and Common Electrode B Configurations DEFIBRILLATOR PROTECTION ESIS FILTERING ECG PATH INPUT MULTIPLEXING COMMON-MODE SELECTION AND AVERAGING WILSON CENTRAL TERMINAL (WCT) RIGHT LEG DRIVE/REFERENCE DRIVE CALIBRATION DAC GAIN CALIBRATION LEAD-OFF DETECTION DC Lead-Off Detection DC Lead-Off and High Gains AC Lead-Off Detection ADC Out of Range SHIELD DRIVER RESPIRATION (ADAS1000-4 MODEL ONLY) Internal Respiration Capacitors External Respiration Path External Respiration Capacitors Respiration Carrier Frequency EVALUATING RESPIRATION PERFORMANCE PACING ARTIFACT DETECTION FUNCTION (ADAS1000-4 ONLY) Choice of Leads Detection Algorithm Overview Pace Edge Threshold Pace Level Threshold Pace Amplitude Threshold Pace Validation Filters Pace Width Filter BIVENTRICULAR PACERS PACE DETECTION MEASUREMENTS EVALUATING PACE DETECTION PERFORMANCE PACE WIDTH PACE LATENCY PACE DETECTION VIA SECONDARY SERIAL INTERFACE FILTERING VOLTAGE REFERENCE GANG MODE OPERATION Master/Slave Synchronizing Devices Calibration Common Mode Right Leg Drive Sequencing Devices into Gang Mode INTERFACING IN GANG MODE SERIAL INTERFACES STANDARD SERIAL INTERFACE Write Mode Write/Read Data Format Data Frames/Packets Read Mode Serial Clock Rate Data Rate and Skip Mode Data Ready (DRDY) Detecting Missed Conversion Data CRC Word Clocks SECONDARY SERIAL INTERFACE RESET PD FUNCTION SPI OUTPUT FRAME STRUCTURE (ECG AND STATUS DATA) SPI REGISTER DEFINITIONS AND MEMORY MAP CONTROL REGISTERS DETAILS INTERFACE EXAMPLES Example 1: Initialize the Device for ECG Capture and Start Streaming Data Example 2: Enable Respiration and Stream Conversion Data (Applies to ADAS1000-4 Only) Example 3: DC Lead-Off and Stream Conversion Data Example 4: Configure 150 Hz Test Tone Sine Wave on Each ECG Channel and Stream Conversion Data Example 5: Enable Pace Detection and Stream Conversion Data (Applies to ADAS1000-4 Only) Example 6: Writing to Master and Slave Devices and Streaming Conversion Data Slave Configuration (ADAS1000-3) Master Configuration (ADAS1000) SOFTWARE FLOWCHART POWER SUPPLY, GROUNDING, AND DECOUPLING STRATEGY AVDD ADCVDD AND DVDD SUPPLIES UNUSED PINS/PATHS LAYOUT RECOMMENDATIONS OUTLINE DIMENSIONS ORDERING GUIDE