AD7818 Analog Devices, AD7818 Datasheet
AD7818
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AD7818 Summary of contents
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... Serial Interface section of this data sheet. The AD7817 is available in a narrow body 0.15" 16-lead small outline IC (SOIC 16-lead, thin shrink small outline pack- age (TSSOP), while the AD7816/AD7818 come in an 8-lead small outline IC (SOIC) and an 8-lead microsmall outline IC (MSOP). PRODUCT HIGHLIGHTS 1 ...
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... AD7816/AD7817/AD7818 AD7817–SPECIFICATIONS Parameter DYNAMIC PERFORMANCE 2 Signal to (Noise + Distortion) Ratio 2 Total Harmonic Distortion 2 Peak Harmonic or Spurious Noise 2 Intermodulation Distortion Second Order Terms Third Order Terms 2 Channel-to-Channel Isolation DC ACCURACY Resolution Minimum Resolution for Which No Missing Codes are Guaranteed 10 2 Relative Accuracy ...
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... AD7816/AD7818 –SPECIFICATIONS Parameter DYNAMIC PERFORMANCE (AD7818 Only) 2 Signal to (Noise + Distortion) Ratio 2 Total Harmonic Distortion 2 Peak Harmonic or Spurious Noise 2 Intermodulation Distortion Second Order Terms Third Order Terms 2 Channel-to-Channel Isolation DC ACCURACY (AD7818 Only) Resolution Minimum Resolution for Which No Missing Codes are Guaranteed ...
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... High Impedance Capacitance NOTES *B and S Versions apply to AD7817 only. For operating temperature ranges, see Ordering Guide. 1 AD7816 and AD7817 temperature sensors specified with external 2.5 V reference, AD7818 specified with on-chip reference. All other specifications with external and on-chip reference (2.5 V). For See Terminology ...
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... RD/WR Rising Edge to OTI Rising Edge ns min SCLK Rising Edge to CONVST Falling Edge (Acquisition Time of T/H) ns min I 200 OUTPUT PIN C L 50pF 200 –5– AD7816/AD7817/AD7818 = 2.5 V. All specifications unless IN MIN MAX to cross 0 2.4 V for OUT DD 1.6V 10% and 0.4 V ...
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... AD7816/AD7817/AD7818 1 ABSOLUTE MAXIMUM RATINGS ( T = 25°C unless otherwise noted AGND . . . . . . . . . . . . . . . . . . . . . . . . . –0 DGND . . . . . . . . . . . . . . . . . . . . . . . . . –0 Analog Input Voltage to AGND –0 IN1 IN4 2 Reference Input Voltage to AGND . . . –0 Digital Input Voltage to DGND . . . . . . –0 Digital Output Voltage to DGND . . . . . –0 Storage Temperature Range . . . . . . . . . . . . . – ...
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... 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. Although the AD7816/AD7817/AD7818 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality ...
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... AD7816/AD7817/AD7818 Pin Mnemonic Description CONVST 1 Logic Input Signal. The convert start signal. A 10-bit analog-to-digital conversion is initiated on the falling edge of this signal. The falling edge of this signal places the track/hold in hold mode. The track/ hold goes into track mode again at the end of the conversion. The state of the CONVST signal is checked at the end of a conversion logic low, the AD7817 will power-down— ...
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... V Positive supply voltage Logic Input and Output. Serial data is clocked in and out of the AD7816/AD7818 at this pin. IN/OUT 7 SCLK Clock Input for the Serial Port. The serial clock is used to clock data into and out of the AD7816/AD7818. Data is clocked out on the falling edge and clocked in on the rising edge. ...
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... Address Register and the Overtemperature Register. These registers can be accessed by carrying out an 8-bit serial write operation to the devices. The 8-bit word or control byte written to the AD7816, AD7817, and AD7818 is transferred to one of the two on-chip registers as follows. Address Register If the five MSBs of the control byte are logic zero, the three LSBs of the control byte are transferred to the Address Regis- ter— ...
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... The A/D converter section consists of a conventional successive-approximation converter based around a capacitor DAC. The AD7816, AD7817, and AD7818 are capable of running 5.5 V power supply and the AD7817 and AD7818 accept an analog input range The on-chip temperature ...
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... V BALANCE 1.2V ADC TRANSFER FUNCTION The output coding of the AD7816, AD7817, and AD7818 is straight binary. The designed code transitions occur at succes- sive integer LSB values (i.e., 1 LSB, 2 LSBs, etc.). The LSB size is = 2.5 V/1024 = 2.44 mV. The ideal transfer characteristic is shown in Figure 10 below. 111...111 111 ...
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... TEMPERATURE MEASUREMENT ERROR DUE TO REFERENCE ERROR The AD7816, AD7817, and AD7818 are trimmed using a pre- cision 2.5 V reference to give the transfer function described previously. To show the effect of the reference tolerance on a temperature reading, the temperature sensor transfer function can be rewritten as a function of the reference voltage and the temperature ...
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... The devices are powered up again on the rising edge of the CONVST signal. Superior power performance can be achieved in this mode of operation by powering up the AD7816, FLUID AD7817, and AD7818 only to carry out a conversion (see Power vs. Throughput section). In Figure 17 the CS line is applicable HEATSINK to the AD7817 only. ...
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... Figure 18 shows how the Automatic Power-Down is imple- mented to achieve the optimum power performance from the AD7816, AD7817, and AD7818. The devices are operated in Mode 2 and the duration of CONVST pulse is set to be equal to the power-up time (2 µs). As the throughput rate of the device is reduced the device remains in its power-down state longer, and the average power consumption over time drops accordingly ...
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... Figure 21). The serial interface on the AD7816 and AD7818 are designed to allow the part to be interfaced to systems that provide a serial clock that is synchronized to the serial data, such as the 80C51, 87C51, 68HC11, 68HC05, and PIC16Cxx microcontrollers ...
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... SCLK DB7 DB6 DB5 IN OUT CONTROL BYTE Figure 21. AD7816/AD7818 Serial Interface Timing Diagram 8-Lead Standard Small Outline Package [SOIC] Narrow Body (R-8) Dimensions shown in millimeters and (inches) 5.00 (0.1968) 4.80 (0.1890 6.20 (0.2440) 4.00 (0.1574) 5.80 (0.2284) 3.80 (0.1497 1.27 (0.0500) 1.75 (0.0688) BSC 1 ...
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... AD7816/AD7817/AD7818 Revision History Location 9/04—Data Sheet changed from REV REV. C. Updated ORDERING GUIDE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 Changes to Operating Modes section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 Changes to Figure Changes to Figure Changes to AD7817 Serial Interface, Read Operation section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 Changes to Figure Changes to Figure –18– Page REV. C ...
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