Datasheet ADAS1000-3, ADAS1000-4 (Analog Devices) - 19

link to page 46
Data Sheet ADAS1000-3/ADAS1000-4 0.121 0.215 AVDD = 3.3V AVDD = 3.3V 0.210 0.101 0.205 0.081 %) ( (V) R D 0.200 L 0.061 RRO HO S N E 0.195 AI HRE G 0.041 T 0.190 0.021 0.185 ECG DC LEAD-OFF THRESHOLD RLD DC LEAD-OFF THRESHOLD 0.001 0.180 GAIN 0 GAIN 1 GAIN 2 GAIN 3
045
–40 –20 0 20 40 60 80
048
GAIN SETTING
10997-
TEMPERATURE (°C)
10997- Figure 17. Typical Gain Error vs. Gain Figure 20. DC Lead-Off Comparator Low Threshold vs. Temperature
0.15 2.420 AVDD = 3.3V AVDD = 3.3V GAIN SETTING 0 = 1.4 0.10 GAIN SETTING 1 = 2.1 2.415 GAIN SETTING 2 = 2.8 0.05 GAIN SETTING 3 = 4.2 2.410 ) 0 V 2.405 %) D ( ( –0.05 L R HO 2.400 S –0.10 RRO 2.395 N E HRE –0.15 AI H T G G 2.390 –0.20 HI 2.385 –0.25 GAIN ERROR G0 –0.30 GAIN ERROR G1 2.380 GAIN ERROR G2 ECG DC LEAD-OFF THRESHOLD GAIN ERROR G3 RLD DC LEAD-OFF THRESHOLD –0.35 2.375 –40 –20 0 20 40 60 80
046
–40 –20 0 20 40 60 80
049
TEMPERATURE (°C)
10997-
TEMPERATURE (°C)
10997- Figure 18. Typical Gain Error for All Gain Settings Across Temperature Figure 21. DC Lead-Off Comparator High Threshold vs. Temperature
5 0 +85°C AVDD = 3.3V AVDD = 3.3V +55°C GAIN SETTING 0 = 1.4 4 –1 +25°C –5°C 3 –40°C –2 2 –3 A) n 1 –4 ( B) E d 0 –5 N ( AI AKAG –1 G E –6 L –2 –7 –3 –8 –4 –9 –5 –10 0.3 0.8 1.3 1.8 2.3
047
1 10 100 1k
050
VOLTAGE (V)
10997-
FREQUENCY (Hz)
10997- Figure 19. Typical ECG Channel Leakage Current over Input Voltage Range Figure 22. Filter Response with 40 Hz Filter Enabled, 2 kHz Data Rate; See vs. Temperature Figure 72 for Digital Filter Overview Rev. B | Page 19 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