Datasheet AD7688 (Analog Devices) - 10

Data Sheet AD7688 TYPICAL PERFORMANCE CHARACTERISTICS 1.5 1.5 POSITIVE INL = +0.31LSB POSITIVE DNL = +0.37LSB NEGATIVE INL = –0.39LSB NEGATIVE DNL = –0.21LSB 1.0 1.0 0.5 0.5 0 0 INL (LSB) DNL (LSB) –0.5 –0.5 –1.0 –1.0 –1.5
02973-001
–1.5
02973-009
0 16384 32768 49152 65535 0 16384 32768 49152 65535 CODE CODE
Figure 7. Integral Nonlinearity vs. Code Figure 10. Differential Nonlinearity vs. Code
300000 160000 VDD = REF = 5V VDD = REF = 5V 256159 136187 140000 250000 124933 120000 200000 100000 150000 80000 COUNTS COUNTS 60000 100000 40000 50000 20000 0 0 2930 2031 0 0 0 0 0 0
02973-007
0
02973-010
0 6F 70 71 72 73 74 75 71 72 73 74 75 76 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
0 100 16384 POINT FFT –20 VDD = REF = 5V 99 FS = 500KSPS F 98 –40 IN = 2kHz SNR = 95.6dB THD = –117.7dB 97 –60 SFDR = –117.9dB 2nd HARM = –125dB 96 –80 3rd HARM = –119dB 95 –100 SNR (dB) 94 –120 93 AMPLITUDE (dB of Full Scale) –140 92 –160 91 –180
02973-008 02973-011
90 0 25 50 75 100 125 150 175 200 225 250 –10 –8 –6 –4 –2 0 FREQUENCY (kHz) INPUT LEVEL (dB)
Figure 9. FFT Plot Figure 12. SNR vs. Input Level Rev. B | Page 9 of 28 Document Outline Features Applications Application Diagram General Description Table of Contents Revision History Specifications Timing Specifications Absolute Maximum Ratings Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Terminology Typical Performance Characteristics Circuit Information Converter Operation Transfer Functions Typical Connection Diagram Analog Input Driver Amplifier Choice Single-to-Differential Driver 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-Write, 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 AD7688 Performance Outline Dimensions Ordering Guide