AD7694 Analog Devices, AD7694 Datasheet
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AD7694
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AD7694 Summary of contents
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... IN−. The reference voltage, REF, is applied externally and can be set up to the supply voltage. Its power scales linearly with throughput. The AD7694 is housed in an 8-lead MSOP package with an operating temperature specified from −40°C to +85°C. Rev. A Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use ...
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... Application Information................................................................ 12 Circuit Information.................................................................... 12 REVISION HISTORY 5/05—Rev Rev. A Updated Format..................................................................Universal Changes to Digital Interface Section............................................ 14 Changes to Figure 25...................................................................... 15 Changes to Evaluating the AD7694’s Performance Section...... 15 7/04—Revision 0: Initial Version Converter Operation.................................................................. 12 Transfer Functions ..................................................................... 12 Typical Connection Diagram ................................................... 13 Analog Input ............................................................................... 13 Driver Amplifier Choice ........................................................... 13 Voltage Reference Input ...
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... See the Analog Input section 16 +6 −4 +4 0.5 ±30 ±2 ±15 ±0.3 ±3.5 ±0.7 ±3.5 ±0.3 ±0.05 250 0 250 150 0 150 −106 −106 AD7694 Unit Bits Bits LSB LSB LSB ppm/°C mV ppm/°C LSB kSPS kSPS ...
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... AD7694 VDD = 2 5. VDD; T REF A Table 3. Parameter Conditions REFERENCE Voltage Range Load Current 250 kSPS, V SAMPLING DYNAMICS −3 dB Input Bandwidth DIGITAL INPUTS Logic Levels V VDD = 4. VDD = 2 VDD = 5. VDD = 3 DIGITAL OUTPUTS Data Format Pipeline Delay +500 μA ...
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... DSDO DIS Symbol Min t CONV t 6.66 CYC t 125 SCK t 50 SCKL t 50 SCKH t 5 HSDO t DSDO DIS Rev Page AD7694 Typ Max Unit 3.2 μs μ Typ Max Unit 4.66 μs μ 120 ns ...
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... AD7694 ABSOLUTE MAXIMUM RATINGS Table 6. Parameter Rating Analog Inputs 1 1 IN+ , IN− GND − 0 VDD + 0 ±130 mA REF GND − 0 VDD + 0.3 V Supply Voltages VDD to GND −0 Digital Inputs to GND −0 VDD + 0.3 V Digital Outputs to GND −0 VDD + 0.3 V Storage Temperature Range − ...
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... Serial Data Clock Input. When CNV is low, the conversion result is shifted out by this clock. 8 VDD P Power Supply analog input digital input digital output; and P = power. REF VDD 1 8 AD7694 IN+ SCK 2 7 TOP VIEW IN– SDO 3 6 (Not to Scale) GND CNV 4 5 Figure 4. 8-Lead MSOP Pin Configuration . REF Rev Page AD7694 ...
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... AD7694 TERMINOLOGY Integral Nonlinearity Error (INL) Linearity error refers to the deviation of each individual code from a line drawn from negative full scale to positive full scale. The point used as negative full scale occurs ½ LSB before the first code transition. Positive full scale is defined as a level 1 ½ ...
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... CODE IN HEX Figure 9. Histogram Input at the Code Center 0 16384 POINT FFT VDD = REF = 2.5V – 150kSPS 20.43kHz IN –40 SNR = 88.5dB THD = –102.7dB SFDR = –105.1dB –60 – FREQUENCY (kHz) Figure 10. FFT Plot AD7694 65536 ...
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... AD7694 100 95 SNR 90 ENOB S/[N+ 2.5 3.0 3.5 4.0 REFERENCE VOLTAGE (V) Figure 11. SNR, S/(N + D), and ENOB vs. Reference Voltage 100 2.5V, –1dB REF 100 FREQUENCY (kHz) Figure 12. S/[ vs. Frequency –80 –85 –90 – 5V, –1dB REF –100 –105 –110 –115 120 FREQUENCY (kHz) Figure 13 ...
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... OFFSET ERROR 0 –2 GAIN ERROR –4 –6 –55 –35 – TEMPERATURE (°C) Figure 17. Offset and Gain Error vs. Temperature 105 125 Rev Page AD7694 ...
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... The AD7694 provides the user with on-chip, track-and-hold and does not exhibit any pipeline delay or latency, making it ideal for multiple, multiplexed channel applications. The AD7694 is specified from 2 5. housed in an 8-lead MSOP. The AD7694 is an improved second source to LTC1864 and LTC1864L. For even better performance, the AD7685 should be considered ...
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... Figure 20 shows an example of the recommended application diagram for the AD7694. ANALOG INPUT Figure 21 shows an equivalent circuit of the AD7694 input structure. The two diodes, D1 and D2, provide ESD protection for the analog inputs, IN+ and IN−. Care must be taken to ensure that the analog input signal never exceeds the supply rails by more than 0 ...
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... Small, low power, and low frequency AD8031 High frequency and low power VOLTAGE REFERENCE INPUT The AD7694 voltage reference input, REF, has a dynamic input impedance and should therefore be driven by a low impedance source with efficient decoupling between the REF and GND pins, as explained in the Layout section. ...
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... The printed circuit board that houses the AD7694 should be designed so that the analog and digital sections are separated and confined to certain areas of the board. The pinout of the AD7694 with all its analog signals on the left side and all its digital signals on the right side eases this task. t ...
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... Integral Model Nonlinearity AD7694ARM ±6 LSB max AD7694ARMRL7 ±6 LSB max AD7694BRM ±4 LSB max AD7694BRMRL7 ±4 LSB max 1 EVAL-AD7694CB 2 EVAL-CONTROL BRD2 2 EVAL-CONTROL BRD3 1 This board can be used as a standalone evaluation board or in conjunction with the EVAL-CONTROL BRDx for evaluation/demonstration purposes. ...