ad7865as-2reel Analog Devices, Inc., ad7865as-2reel Datasheet
ad7865as-2reel
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ad7865as-2reel Summary of contents
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GENERAL DESCRIPTION The AD7865 is a fast, low power, four-channel simultaneous sampling 14-bit A/D converter that operates from a single 5 V supply. The part contains a 2.4 µs successive approximation ADC, four track/hold amplifiers, 2.5 V reference, on-chip ...
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AD7865–SPECIFICATIONS Parameter SAMPLE AND HOLD –3 dB Full Power Bandwidth Aperture Delay Aperture Jitter Aperture Delay Matching 2 DYNAMIC PERFORMANCE 3 Signal to (Noise + Distortion) Ratio @ 25°C AD7865-1, AD7865-3 AD7865 MIN MAX AD7865-1, AD7865-3 AD7865-2 ...
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Parameter REFERENCE INPUT/OUTPUT V IN Input Voltage Range REF Input Capacitance REF V OUT Output Voltage REF V OUT Error @ 25°C REF V OUT Error REF MIN MAX V OUT Temperature Coefficient REF ...
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AD7865 TIMING CHARACTERISTICS Parameter Versions t 2.4 CONV 3.2 t 0.35 ACQ t No. of Channels BUSY × (t CONV 3 t —External V 1 WAKE-UP REF Read Operation t 0 ...
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... V, ± AD7865YS-1 AD7865AS 2 AD7865BS 2 AD7865YS 2 ± 2.5 V AD7865AS-3 ± 2.5 V AD7865BS-3 ± 2.5 V AD7865YS-3 FRSTDATA CLK IN/SL1 INT/EXT CLK/SL2 CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection ...
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AD7865 Pin Mnemonic Description Busy Output. The busy output is triggered high by the rising edge of CONVST and remains 1 BUSY high until conversion is completed on all selected channels. 2 FRSTDATA First Data Output. FRSTDATA is a logic ...
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Pin Mnemonic Description Reference Input/Output. This pin provides access to the internal reference (2.5 V ± REF and also allows the internal reference to be overdriven by an external reference source (2.5 V ± 5%). A ...
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AD7865 TERMINOLOGY Signal to (Noise + Distortion) Ratio This is the measured ratio of signal to (noise + distortion) at the output of the A/D converter. The signal is the rms amplitude of the fundamental. Noise is the rms sum ...
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CONVERTER DETAILS The AD7865 is a high speed, low power, four-channel simulta- neous sampling 14-bit A/D converter that operates from a single 5 V supply. The part contains a 2.4 µs successive approximation ADC, four track/hold amplifiers, an internal 2.5 ...
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AD7865 CIRCUIT DESCRIPTION Analog Input Section The AD7865 is offered as three part types, the AD7865-1 where each input can be configured for ± ± input voltage range, the AD7865-3 which handles input voltage ...
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AD7865-3 Figure 4 shows the analog input section of the AD7865-3. The analog input range is ± 2 the V input can be left unconnected but connected to a poten- tial then that potential must ...
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AD7865 TIMING AND CONTROL Reading Between Each Conversion in the Conversion Sequence Figure 7 shows the timing and control sequence required to obtain the optimum throughput rate from the AD7865. To obtain the optimum throughput from the AD7865 the user ...
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Accessing the Output Data Registers There are four Output Data Registers, one for each of the four possible conversion results from a conversion sequence. The result of the first conversion in a conversion sequence is placed in Register 1 and ...
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AD7865 CLK CONVST FRSTDATA EOC RD BUSY Using an ...
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CONVST BUSY STBY When operating the AD7865 in a standby mode between con- versions, the power savings can be significant. For example, with a throughput rate of 10 kSPS and external reference, the AD7865 will be powered up 11 µs ...
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AD7865 7000 6000 5000 4000 3000 2000 1000 0 ADC CODE The output spectrum from the ADC is evaluated by applying a sine wave signal of very low distortion to the analog input. A Fast Fourier Transform (FFT) plot is ...
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AC Linearity Plots The plots shown in Figure 18 below show typical DNL and INL for the AD7865. 0.60 0 –0.60 0 4000 8000 ADC – Code 0.60 0 –0.60 0 4000 8000 ADC – Code MICROPROCESSOR INTERFACING The high ...
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AD7865 The MC68000 AS and R/W outputs are used to generate a separate RD input signal for the AD7865 used to drive the 68000 DTACK input to allow the processor to execute a normal read operation to the ...
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OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 44-Lead Plastic Quad Flatpack (S-44) 0.548 (13.925) 0.546 (13.875) 0.096 (2.44) 0.398 (10.11) MAX 0.390 (9.91) 0.037 (0.94) 8 0.025 (0.64) 33 0.8 34 SEATING PLANE TOP VIEW (PINS DOWN ...