Datasheet AD7787 (Analog Devices) - 10
| Manufacturer | Analog Devices |
| Description | Low Power, 2-Channel 24-Bit Sigma-Delta ADC |
| Pages / Page | 21 / 10 — Data Sheet. AD7787. TYPICAL PERFORMANCE CHARACTERISTICS. VDD = 3V. –10. … |
| Revision | A |
| File Format / Size | PDF / 364 Kb |
| Document Language | English |
Data Sheet. AD7787. TYPICAL PERFORMANCE CHARACTERISTICS. VDD = 3V. –10. REF = 2.048V. 1.1875Hz UPDATE RATE. –20. TA = 25°C. –30
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Text Version of Document
Data Sheet AD7787 TYPICAL PERFORMANCE CHARACTERISTICS 0 9 VDD = 3V –10 V 8 REF = 2.048V 1.1875Hz UPDATE RATE –20 TA = 25°C 7 –30 RMS NOISE = 1.25
µ
F –40 6 –50 5 –60 dB 4 –70 OCCURRENCE –80 3 –90 2 –100 1 –110
04477-0-012
–120
04477-0-014
0 0 20 40 60 80 100 120 140 160 8388592 8388616 FREQUENCY (Hz) CODE
Figure 6. Frequency Response with 16.6 Hz Update Rate Figure 9. Noise Histogram for Clock Divide-by-8 Mode (CDIV0 = CDIV1 = 1)
VDD = 3V 8388616 100 VREF = 2.048V 9.5Hz UPDATE RATE TA = 25°C RMS NOISE = 1
µ
V 80 60 CODE OCCURRENCE 40 20 VDD = 3V, VREF = 2.048V 1.1875Hz UPDATE RATE
04477-0-010
T 0 A = 25°C, RMS NOISE = 1.25
µ
F
04477-0-013
8388591 8388619 8388592 CODE 0 20 40 60 80 100 READ NO.
Figure 7. Noise Distribution Histogram (CDIV1 = CDIV0 = 0) Figure 10. Noise Plot in Clock Divide-by-8 Mode (CDIV0 = CDIV1 = 1)
8388619 3.0 VDD = 5V UPDATE RATE = 16.6Hz TA = 25°C 2.5 2.0
µ
V) 1.5 CODE RMS NOISE ( 1.0 0.5 VDD = 3V, VREF = 2.048V, 9.5Hz UPDATE RATE TA = 25°C, RMS NOISE = 1
µ
V
04477-0-011
8388591
04477-0-015
0 0 200 400 600 800 1000 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 READ NO. VREF (V)
Figure 8. Typical Noise Plot with 16.6 Hz Update Rate (CDIV1 = CD1V0 = 0) Figure 11. RMS Noise vs. Reference Voltage Rev. A | Page 9 of 20 Document Outline Specifications Timing Characteristics Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics On-Chip Registers Communications Register (RS1, RS0 = 0, 0) Status Register (RS1, RS0 = 0, 0; Power-On/Reset = 0×8C) Mode Register (RS1, RS0 = 0, 1; Power-On/Reset = 0×02) Filter Register (RS1, RS0 = 1, 0; Power-On/Reset = 0×04) Data Register (RS1, RS0 = 1, 1; Power-On/Reset = 0×000000) ADC Circuit Information Overview Noise Performance Reduced Current Modes Digital Interface Single Conversion Mode Continuous Conversion Mode Continuous Read Mode Circuit Description Analog Input Channel Bipolar/Unipolar Configuration Data Output Coding Reference Input VDD Monitor Grounding and Layout Applications Battery Monitoring Outline Dimensions Ordering Guide
µ
F –40 6 –50 5 –60 dB 4 –70 OCCURRENCE –80 3 –90 2 –100 1 –110
04477-0-012
–120
04477-0-014
0 0 20 40 60 80 100 120 140 160 8388592 8388616 FREQUENCY (Hz) CODE
Figure 6. Frequency Response with 16.6 Hz Update Rate Figure 9. Noise Histogram for Clock Divide-by-8 Mode (CDIV0 = CDIV1 = 1)
VDD = 3V 8388616 100 VREF = 2.048V 9.5Hz UPDATE RATE TA = 25°C RMS NOISE = 1
µ
V 80 60 CODE OCCURRENCE 40 20 VDD = 3V, VREF = 2.048V 1.1875Hz UPDATE RATE
04477-0-010
T 0 A = 25°C, RMS NOISE = 1.25
µ
F
04477-0-013
8388591 8388619 8388592 CODE 0 20 40 60 80 100 READ NO.
Figure 7. Noise Distribution Histogram (CDIV1 = CDIV0 = 0) Figure 10. Noise Plot in Clock Divide-by-8 Mode (CDIV0 = CDIV1 = 1)
8388619 3.0 VDD = 5V UPDATE RATE = 16.6Hz TA = 25°C 2.5 2.0
µ
V) 1.5 CODE RMS NOISE ( 1.0 0.5 VDD = 3V, VREF = 2.048V, 9.5Hz UPDATE RATE TA = 25°C, RMS NOISE = 1
µ
V
04477-0-011
8388591
04477-0-015
0 0 200 400 600 800 1000 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 READ NO. VREF (V)
Figure 8. Typical Noise Plot with 16.6 Hz Update Rate (CDIV1 = CD1V0 = 0) Figure 11. RMS Noise vs. Reference Voltage Rev. A | Page 9 of 20 Document Outline Specifications Timing Characteristics Absolute Maximum Ratings ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics On-Chip Registers Communications Register (RS1, RS0 = 0, 0) Status Register (RS1, RS0 = 0, 0; Power-On/Reset = 0×8C) Mode Register (RS1, RS0 = 0, 1; Power-On/Reset = 0×02) Filter Register (RS1, RS0 = 1, 0; Power-On/Reset = 0×04) Data Register (RS1, RS0 = 1, 1; Power-On/Reset = 0×000000) ADC Circuit Information Overview Noise Performance Reduced Current Modes Digital Interface Single Conversion Mode Continuous Conversion Mode Continuous Read Mode Circuit Description Analog Input Channel Bipolar/Unipolar Configuration Data Output Coding Reference Input VDD Monitor Grounding and Layout Applications Battery Monitoring Outline Dimensions Ordering Guide
