AD7690 Analog Devices, AD7690 Datasheet
AD7690
Specifications of AD7690
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AD7690 Summary of contents
Page 1
... SDI input, to daisy-chain several ADCs on a single, 3-wire bus and provides an optional busy indicator compatible with 1 logic, using the separate VIO supply. The AD7690 is housed in a 10-lead MSOP or a 10-lead QFN (LFCSP) with operation specified from −40°C to +85°C. 196608 262144 One Technology Way, P ...
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... Change to Figure 22 Caption ........................................................ 11 Changes to Circuit Information Section ..................................... 12 Change to Table 7 ........................................................................... 13 Change to Endnote 1 of Figure 26 ................................................ 13 Added Figure 29 ............................................................................. 14 Changes to Driver Amplifier Choice Section ............................. 14 Change to Evaluating the AD7690’s Performance Section ....... 23 Updated Outline Dimensions ....................................................... 24 Changes to Ordering Guide .......................................................... 24 4/06—Revision 0: Initial Version Rev Page ...
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... REF 0.1 REF REF 65 1 400 400 ±0.75 +1.5 ±0.5 +1.25 0.75 ±2 +40 ±0.3 +0.8 ±0.3 ±0.25 102 125 101.5 96 −125 −125 101.5 115 AD7690 Unit Bits kSPS ns Bits 2 LSB LSB LSB LSB ppm/°C mV ppm/°C LSB ...
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... AD7690 VDD = 4. 5.25 V, VIO = 2 VDD, V Table 3. Parameter Conditions REFERENCE Voltage Range Load Current 400 kSPS, REF = 5 V SAMPLING DYNAMICS −3 dB Input Bandwidth Aperture Delay VDD = 5 V DIGITAL INPUTS Logic Levels DIGITAL OUTPUTS Data Format Pipeline Delay ...
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... DIS t SSDICNV t HSDICNV t SSCKCNV t HSCKCNV t SSDISCK t HSDISCK t DSDOSDI 30% VIO t DELAY 1.4V NOTES VIO ABOVE 2.5V, VIO – 0.5V IF VIO BELOW 2.5V. 2. 0.8V IF VIO ABOVE 2.5V, 0.5V IF VIO BELOW 2.5V. Rev Page AD7690 , unless otherwise noted. MAX Min Typ Max 0.5 2.1 400 2 ...
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... AD7690 ABSOLUTE MAXIMUM RATINGS Table 5. Parameter Rating Analog Inputs 1 1 IN+, IN− GND − 0 VDD + 0 ±130 mA REF GND − 0 VDD + 0.3 V Supply Voltages VDD, VIO to GND −0 VDD to VIO ±7 V Digital Inputs to GND −0 VIO + 0.3 V Digital Outputs to GND − ...
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... SCK TOP VIEW IN– SDO (Not to Scale) GND 5 6 CNV NOTES 1. THE EXPOSED PAD IS NOT CONNECTED INTERNALLY. FOR INCREASED RELIABILITY OF THE SOLDER JOINTS RECOMMENDED THAT THE PAD BE SOLDERED TO THE GROUND PLANE. Figure 6. 10-Lead QFN (LFCSP) Pin Configuration AD7690 ...
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... AD7690 TERMINOLOGY Integral Nonlinearity Error (INL) INL refers to the deviation of each individual code from a line drawn from negative full scale through 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 1½ LSB beyond the last code transition ...
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... CODE IN HEX Figure 11. Histogram Input at the Code Transition SNR THD –10 –8 –6 –4 –2 INPUT LEVEL (dB) Figure 12. SNR, THD vs. Input Level AD7690 262144 –110 –112 –114 –116 –118 –120 –122 –124 –126 –128 – ...
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... AD7690 104 102 100 2.3 2.7 3.1 3.5 3.9 4.3 REFERENCE VOLTAGE (V) Figure 13. SNR, SINAD, and ENOB vs. Reference Voltage 103 102 101 100 –55 –35 – TEMPERATURE (°C) Figure 14. SNR vs. Temperature 105 100 5V, –1dB REF 100 FREQUENCY (kHz) Figure 15 ...
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... Rev Page GAIN ERROR ZERO ERROR –35 – 105 TEMPERATURE (°C) Figure 22. Zero and Gain Error vs. Temperature VDD = 5V, 85°C VDD = 5V, 25° 100 SDO CAPACITIVE LOAD (pF) Delay vs. Capacitance Load and Supply DSDO AD7690 125 120 ...
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... The AD7690 provides the user with an on-chip track-and-hold and does not exhibit pipeline delay or latency, making it ideal for multiple multiplexed channel applications. The AD7690 is specified from 4. 5.25 V and can be interfaced to any 1 digital logic family housed in a 10-lead MSOP or a tiny 10-lead QFN (LFCSP) that allows space savings and flexible configurations ...
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... Transfer Functions The ideal transfer characteristic for the AD7690 is shown in Figure 25 and Table 7. 011...111 011...110 011...101 100...010 100...001 100...000 –FSR –FSR + 1LSB –FSR + 0.5LSB +FSR – 1.5LSB ANALOG INPUT Figure 25. ADC Ideal Transfer Function V+ V+ ...
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... SNR and transition noise performance of the AD7690. The noise from the driver is filtered by the AD7690 analog input circuit’s 1-pole, low- pass filter made one is used. Because the typical noise of the AD7690 is 28 μV rms, the SNR degradation due to the amplifier is SNR 1000 ...
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... R5 = 10.5 kΩ, and R6 = 9.76 kΩ. ±10V, ±5V, ... VOLTAGE REFERENCE INPUT The AD7690 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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... SDI is high, and the chain mode is selected if SDI is low. The SDI hold time is such that when SDI and CNV are connected together, the chain mode is selected. In either mode, the AD7690 offers the option of forcing a start VIO bit in front of the data bits. This start bit can be used as a busy signal indicator to interrupt the digital host and trigger the data reading ...
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... CS MODE, 3-WIRE WITHOUT BUSY INDICATOR This mode is usually used when a single AD7690 is connected to an SPI-compatible digital host. The connection diagram is shown in Figure 34, and the corresponding timing is given in Figure 35. With SDI tied to VIO, a rising edge on CNV initiates a conversion, selects the CS mode, and forces SDO to high impedance ...
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... AD7690 CS MODE, 3-WIRE WITH BUSY INDICATOR This mode is usually used when a single AD7690 is connected to an SPI-compatible digital host having an interrupt input. The connection diagram is shown in Figure 36, and the corresponding timing is given in Figure 37. With SDI tied to VIO, a rising edge on CNV initiates a conversion, selects the CS mode, and forces SDO to high impedance ...
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... Although the rising edge can be used to capture the data, a digital host using the SCK falling edge allows a faster reading rate, provided it has an acceptable hold time. After the 18 falling edge or when SDI goes high (whichever occurs first), SDO returns to high impedance and another AD7690 can be read. CNV CNV AD7690 ...
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... AD7690 CS MODE, 4-WIRE WITH BUSY INDICATOR This mode is usually used when a single AD7690 is connected to an SPI-compatible digital host, which has an interrupt input, and it is desired to keep CNV, which is used to sample the analog input, independent of the signal used to select the data reading. ...
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... Although the rising edge can be used to capture the data, a digital host using the SCK falling edge allows a faster reading rate and consequently more AD7690s in the chain, provided the digital host has an acceptable hold time. The maximum conversion rate may be reduced due to the total readback time. ...
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... When all ADCs in the chain have completed their conversions, the SDO pin of the ADC closest to the digital host (see the AD7690 ADC labeled C in Figure 44) is driven high. This transition on SDO can be used as a busy indicator to trigger the data readback controlled by the digital host ...
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... The pinout of the AD7690, with its analog signals on the left side and its digital signals on the right side, eases this task. Avoid running digital lines under the device because these couple noise onto the die unless a ground plane under the AD7690 is used as a shield ...
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... ORDERING GUIDE 1 Model Notes Temperature Range AD7690BCPZRL –40°C to +85°C AD7690BCPZRL7 –40°C to +85°C AD7690BRMZ –40°C to +85°C AD7690BRMZ-RL7 –40°C to +85°C 2 EVAL-AD7690CBZ 3 EVAL-CONTROL BRD2 EVAL-CONTROL BRD3 RoHS Compliant Part. 2 This board can be used as a standalone evaluation board or in conjunction with the EVAL-CONTROL BRDx for evaluation/demonstration purposes. ...