Datasheet AD7686 (Analog Devices) - 10

Data Sheet AD7686 TYPICAL PERFORMANCE CHARACTERISTICS 2.0 2.0 POSITIVE INL = +0.52LSB POSITIVE DNL = +0.35LSB NEGATIVE INL = –0.38LSB NEGATIVE DNL = –0.36LSB 1.5 1.5 1.0 1.0 0.5 0.5 ) ) SB SB (L 0 (L 0 L L IN DN –0.5 –0.5 –1.0 –1.0 –1.5 –1.5
007 010
–2.0
02969-
–2.0
02969-
0 16384 32768 49152 65535 0 16384 32768 49152 65535 CODE CODE
Figure 7. Integral Nonlinearity vs. Code Figure 10. Differential Nonlinearity vs. Code
250000 160000 VDD = REF = 5V VDD = REF = 5V 140000 133575 202719 200000 124164 120000 100000 150000 S S 80000 UNT UNT CO 100000 CO 60000 40000 50000 27583 30770
1
20000
1 008 0
0 0 26 22 0 0 0 0 1703 1678 0 0
02969-
0
02969-
0 8026 8027 8028 8029 802A 802B 802C 802D 802E 8024 8025 8026 8027 8028 8029 802A 802B CODE IN HEX CODE IN HEX
Figure 8. Histogram of a DC Input at the Code Center Figure 11. Histogram of a DC Input at the Code Transition
0 95 –105 8192 POINT FFT VDD = REF = 5V –20 fS = 500kSPS ) fIN = 19.99kHz E 94 –108 –40 SNR = 92.8dB CAL THD = –108.7dB THD S –60 SECOND HARMONIC = –110.1dB L L THIRD HARMONIC = –119.2dB 93 –111 –80 B) SNR B) d d OF FU –100 dB NR ( HD ( ( S 92 –114 T E D –120 LITU P –140 91 –117 M A –160
009 012 02969-
–180
02969-
90 –120 0 20 40 60 80 100 120 140 160 180 200 220 240 –10 –8 –6 –4 –2 0 FREQUENCY (kHz) INPUT LEVEL (dB)
Figure 9. FFT Plot Figure 12. SNR and THD vs. Input Level Rev. C | Page 9 of 28 Document Outline Features Applications Functional Block Diagram General Description Table of Contents Revision History Specifications Timing Specifications Absolute Maximum Ratings ESD Caution Pin Configurations and Function Descriptions Terminology Typical Performance Characteristics Theory of Operation Circuit Information Converter Operation Transfer Functions Typical Connection Diagram Analog Input Driver Amplifier Choice Voltage Reference Input Power Supply Supplying the ADC from the Reference Digital Interface CS/ MODE 3-Wire, No Busy Indicator CS/ Mode 3-Wire with Busy Indicator CS/ Mode 4-Wire, No Busy Indicator CS/ Mode 4-Wire with Busy Indicator Chain Mode, No Busy Indicator Chain Mode with Busy Indicator Application Hints Layout Evaluating the Performance of the AD7686 True 16-Bit Isolated Application Example Outline Dimensions Ordering Guide