AD7714YRUZ Analog Devices Inc, AD7714YRUZ Datasheet
AD7714YRUZ
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AD7714YRUZ Summary of contents
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FEATURES Charge Balancing ADC 24 Bits No Missing Codes 0.0015% Nonlinearity Five-Channel Programmable Gain Front End Gains from 1 to 128 Can Be Configured as Three Fully Differential Inputs or Five Pseudo-Differential Inputs Three-Wire Serial Interface SPI™, QSPI™, MICROWIRE™ ...
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AD7714-5–SPECIFICATIONS f = 2.4576 MHz unless otherwise noted. All specifications T CLK IN Parameter STATIC PERFORMANCE No Missing Codes Output Noise Integral Nonlinearity Unipolar Offset Error 3 Unipolar Offset Drift Bipolar Zero Error 3 Bipolar Zero Drift 4 Positive Full-Scale ...
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AD7714-3–SPECIFICATIONS f = 2.4576 MHz unless otherwise noted. All specifications T CLK IN Parameter STATIC PERFORMANCE No Missing Codes Output Noise Integral Nonlinearity Unipolar Offset Error 3 Unipolar Offset Drift Bipolar Zero Error 3 Bipolar Zero Drift 4 Positive Full-Scale ...
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AD7714–SPECIFICATIONS (AD7714-5); REF IN(–) = AGND; MCLK MHz to 2.4576 MHz unless otherwise noted. All specifications T Parameter A Versions 14 TRANSDUCER BURNOUT Current 1 Initial Tolerance Drift 0.1 SYSTEM CALIBRATION 15 Positive Full-Scale Calibration Limit (1.05 ...
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AD7714Y–SPECIFICATIONS and +2.5 V with REF IN(–) = AGND; MCLK IN = 2.4576 MHz unless otherwise noted. All specifications T DD Parameter STATIC PERFORMANCE No Missing Codes Output Noise Integral Nonlinearity Unipolar Offset Error 3 Unipolar ...
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AD7714Y Parameter LOGIC OUTPUTS (Continued Output High Voltage OH Floating State Leakage Current 13 Floating State Output Capacitance D ata Output Coding 14 TRANSDUCER BURNOUT Current Initial Tolerance Drift SYSTEM CALIBRATION 15 Positive Full-Scale Calibration Limit 15 Negative ...
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TIMING CHARACTERISTICS Limit MIN Parameter (A, Y Versions 400 CLKIN 2.5 t 0.4 t CLK IN LO CLK IN t 0.4 t CLK IN HI CLK IN t 500 t DRDY CLK IN ...
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AD7714 ABSOLUTE MAXIMUM RATINGS +25 C unless otherwise noted AGND . . . . . . . . . . . . . . . . . . . . . . . . –0.3 ...
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DIP/SOIC PIN NUMBERS Pin No. Mnemonic Function 1 SCLK Serial Clock. Logic Input. An external serial clock is applied to this input to access serial data from the AD7714. This serial clock can be a continuous clock with all data ...
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AD7714 Pin No. Mnemonic Function CS 19 Chip Select. Active low Logic Input used to select the AD7714. With this input hard-wired low, the AD7714 can operate in its three-wire interface mode with SCLK, DIN and DOUT used to interface ...
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AD7714-5 OUTPUT NOISE Table Ia shows the output rms noise and effective resolution for some typical notch and –3 dB frequencies for the AD7714-5 with f = 2.4576 MHz while Table Ib gives the information for f CLK IN with ...
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AD7714 AD7714-3 OUTPUT NOISE Table IIa shows the output rms noise and effective resolution for some typical notch and –3 dB frequencies for the AD7714-3 with f = 2.4576 MHz while Table IIb gives the information for f CLK IN ...
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BUFFERED MODE NOISE Table III shows the typical output rms noise and effective resolution for some typical notch and –3 dB frequencies for the AD7714- 5 with f = 2.4576 MHz and BUFFER = +5 V. Table IV gives the ...
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AD7714 ON-CHIP REGISTERS The AD7714 contains eight on-chip registers which can be accessed via the serial port of the part. The first of these is a Communica- tions Register which controls the channel selection, decides whether the next operation is ...
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CH2–CH0 Channel Select. These three bits select a channel either for conversion or for access to calibration coefficients as outlined in Table VII. There are three pairs of calibration registers on the part. In fully differential mode, the part has ...
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AD7714 MD2 MD1 MD0 Operating Mode (continued System-Offset Calibration; this activates system-offset calibration on the channel selected by CH2, CH1 and CH0 of the Communications Register. This is a one step calibration sequence and when complete the ...
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Filter Registers. Power On/Reset Status: Filter High Register: 01 Hex. Filter Low Register: 40 Hex. There are two 8-bit Filter Registers on the AD7714 from which data can either be read or to which data can be written. Tables IX ...
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AD7714 Test Register (RS2–RS0 = The part contains a Test Register which is used in testing the device. The user is advised not to change the status of any of the bits in this register from the ...
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CIRCUIT DESCRIPTION The AD7714 is a sigma-delta A/D converter with on-chip digi- tal filtering, intended for the measurement of wide dynamic range, low frequency signals such as those in weigh-scale, pres- sure transducer, industrial control or process control applica- tions. ...
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AD7714 ANALOG INPUT Analog Input Ranges The AD7714 contains six analog input pins (labelled AIN1 to AIN6) which can be configured as either three fully differential input channels or five pseudo-differential input channels. Bits CH0, CH1 and CH2 of the ...
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Table XIV. Input Sampling Frequency vs. Gain Gain Input Sampling Freq ( /64 (38.4 kHz @ f CLK IN CLK /64 (76.8 kHz @ f CLK /64 (153.6 ...
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AD7714 In addition, the digital filter does not provide any rejection at integer multiples of the digital filter’s sample frequency. How- ever, the input sampling on the part provides attenuation at multiples of the digital filter’s sampling frequency so that ...
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ANALOG FILTERING The digital filter does not provide any rejection at integer mul- tiples of the input sampling frequency, as outlined earlier. How- ever, due to the AD7714’s high oversampling ratio, these bands occupy only a small fraction of the ...
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AD7714 The part also offers ZS Self-Calibration and FS Self-Calibration options. In these cases, the part performs just a zero-scale or full-scale calibration respectively and not a full calibration of the part. A full-scale calibration should not be carried out ...
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System-Offset Calibration System-offset calibration is a variation of both the system cali- bration and self-calibration. In this case, the zero-scale point is determined in exactly the same way System Calibration. The system zero-scale point is presented to ...
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AD7714 Power-Up and Calibration On power-up, the AD7714 performs an internal reset which sets the contents of the internal registers to a known state. There are default values loaded to all registers after a power-on or reset. The default values ...
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The SYNC input can also be used as a start convert command allowing the AD7714 to be operated in a conventional converter fashion. In this mode, the rising edge of SYNC starts conversion and the falling edge of DRDY indicates ...
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AD7714 1.0 0.9 0.8 MCLK IN = 2.4576MHz 0.7 0.6 0.5 MCLK IN = 1MHz 0.4 0.3 0.2 0.1 0 2.85 3.15 3.45 3.75 4.05 4.35 SUPPLY VOLTAGE (AV & Figure 5. I vs. Supply Voltage DD Grounding ...
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DIGITAL INTERFACE The AD7714’s programmable functions are controlled using a set of on-chip registers as previously outlined. Data is written to these registers via the part’s serial interface, and read access to the on-chip registers is also provided by this ...
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AD7714 CONFIGURING THE AD7714 The AD7714 contains eight on-chip registers that can be accessed via the serial interface. Communication with any of these registers is initiated by writing to the Communications Register first. Figure 8 outlines a flow diagram of ...
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MICROCOMPUTER/MICROPROCESSOR INTERFACING The AD7714’s flexible serial interface allows for easy interface to most microcomputers and microprocessors. The flowchart of Figure 8 outlines the sequence which should be followed when interfacing a microcontroller or microprocessor to the AD7714. Figures 9, 10 ...
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AD7714 interfaces which require control of the CS input on the AD7714, one of the port bits of the 8XC51 (such as P1.1), which is con- figured as an output, can be used to drive the CS input ...
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This program has read and write routines for the 68HC11 to interface to the AD7714 and the sample program sets the various registers and then reads 1000 samples from the part. */ #include <math.h> #include <io6811.h> #define NUM_SAMPLES 1000 ...
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AD7714 APPLICATIONS The on-chip PGA allows the AD7714 to handle an analog input voltage range as low full-scale with V The differential inputs of the part allow this analog input range to have an absolute value anywhere ...
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Temperature Measurement Another application area for the AD7714 is in temperature measurement. Figure 13 outlines a connection from a thermo- couple to the AD7714. In this application, the AD7714 is oper- ated in its buffered mode to allow large decoupling ...
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AD7714 RTD Measurement Figure 14 shows another temperature measurement application for the AD7714. In this case, the transducer is an RTD (Resis- tive Temperature Device), a PT100. The arrangement lead RTD configuration. There are voltage drops across ...
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Data Acquisition The AD7714 with its three differential channels (or five pseudo- differential channels) is suited to low bandwidth, high resolution data acquisition systems. In addition, the three-wire digital interface allows this data acquisition front end to be isolated with ...
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AD7714 Smart Transmitters Another area where the low power, single supply, three-wire interface capabilities is of benefit is in smart transmitters. Here, the entire smart transmitter must operate from the loop. Tolerances in the loop ...
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PAGE INDEX Topic FEATURES . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ...
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AD7714 24-Lead Plastic DIP (N-24) 1.228 (31.19) 1.226 (31.14 0.260 ± 0.001 (6.61 ± 0.03 PIN 1 0.130 (3.30) 0.128 (7.62) 0.02 (0.5) 0.11 (2.79) 0.07 (1.78) SEATING PLANE 0.019 (0.41) 0.016 (2.28) 0.05 (1.27) NOTES: ...