AD421BN Analog Devices Inc, AD421BN Datasheet
AD421BN
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AD421BN Summary of contents
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FEATURES Current Output ® HART Compatible 16-Bit Resolution and Monotonicity 0.01% Integral Nonlinearity Regulator Output 2.5 V and 1.25 V Precision Reference 750 A Quiescent Current max Programmable Alarm ...
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AD421–LOOP-POWERED SPECIFICATIONS Parameter OUTPUT CHARACTERISTICS 3 Current Loop Voltage Compliance Full-Scale Settling Time Output Impedance AC Loop Voltage Sensitivity VOLTAGE REGULATOR Output Voltage ( Mode 3.3 V Mode 5 V Mode Externally Available Current Line Regulation ...
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TIMING CHARACTERISTICS Parameter (B Versions) t 100 NOTES 1 Guaranteed by characterization at initial product ...
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... REF OUT1 REF OUT2 REF IN LV LATCH CLOCK DATA LOOP RTN ORDERING GUIDE Temperature Model Range AD421BN –40°C to +85°C AD421BR –40°C to +85°C AD421BRRL –40°C to +85°C EVAL-AD421EB Evaluation Board *N = Plastic DIP SOIC. –4– DIP and SOIC 1 ...
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Pin No. Mnemonic Function 1 REF OUT1 Reference Output 1. A precision +1.25 V reference is provided at this pin intended as a precision ref- erence source for other devices in the transmitter. REF OUT1 is a buffered ...
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AD421 CIRCUIT DESCRIPTION The AD421 is designed for use in loop-powered 4–20 mA smart transmitter applications. A smart transmitter remote in- strument, controls its current output signal on the same pair of wires from which it receives its ...
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SWITCHED AD421 CURRENT SOURCES 80k 40 Figure 4. Current Amplifier The BOOST pin is normally tied to the V input code varies from all zeros to full scale, the output current from the NPN transistor and thus the total loop ...
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AD421 of 11.147 mA. With 16 clock pulses between consecutive latch signals data written is for normal operation. Table II. Ideal Input/Output Code Table for Operation Code 0000 0000 0000 ...
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The HC11 generates the requisite eight clock pulses with data valid on the rising edges. After the MSBY is transmitted, the least significant byte (LSBY) is loaded from memory and transmitted in a similar fashion. To complete the transfer, the ...
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AD421 A capacitor of 0.01 µF connected between COMP and DRIVE is required to stabilize the feedback loop formed with the regulator op amp and the external pass transistor. An external snubber circuit of 1 kΩ and 1000 pF is ...
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SENSORS RTD REF ANALOG TO AMBIENT DIGITAL TEMP CONVERTER SENSOR AD7714/ AD7715 MCLK IN MCLK OUT CS DATA OUT SCLK DATA IN AGND DGND Figure 14. AD421 in Smart Transmitter Application ...
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AD421 0 SENSORS RTD REF 100k ANALOG TO AMBIENT DIGITAL TEMP CONVERTER SENSOR AD7714/ AD7715 MCLK IN MCLK OUT CS DATA OUT SCLK DATA IN AGND DGND Figure 17. AD421 in HART ...
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Battery Backup Figure 19 shows an application circuit for the AD421 where the micro and memory sections of the circuitry are protected against losing data if the loop is broken. The backup circuit switches from V to battery voltage without ...
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AD421 0.210 (5.33) 0.160 (4.06) 0.115 (2.93) 0.0118 (0.30) 0.0040 (0.10) OUTLINE DIMENSIONS Dimensions shown in inches and (mm). 16-Lead Plastic DIP (N-16) 0.840 (21.34) 0.745 (18.92 0.280 (7.11) 0.240 (6.10 0.325 (8.26) 0.300 (7.62) PIN ...