ds1720 Maxim Integrated Products, Inc., ds1720 Datasheet
ds1720
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ds1720 Summary of contents
Page 1
... DESCRIPTION The DS1720 Digital Thermometer and Thermostat provides 9–bit temperature readings which indicate the temperature of the device. With three thermal alarm out-puts, the DS1720 can also act as a thermostat driven high if the DS1720’s temperature is greater than or equal to a user–defined temperature ...
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... A block diagram of the temperature measurement circuitry is shown in Figure 2. The DS1720 measures temperature by counting the number of clock cycles that an oscillator with a low temperature coefficient goes through during a gate period determined by a high temperature coefficient oscillator. The counter is preset with a base count that corresponds to –55°C. If the counter reaches zero before the gate period is over, the temperature register, which is also preset to the – ...
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... DS1720 FUNCTIONAL BLOCK DIAGRAM Figure DS1720 ...
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... DS1720 as either a 9–bit word (taking words, with the most significant 7 bits being ignored or set to zero, as illustrated in Table 1. After the MSB, the DS1720 will output 0s. Note that temperature is represented in the DS1720 in terms of a ½°C LSB, yielding the following 9–bit format: MSB ...
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... OPERATION–THERMOSTAT CONTROLS Three thermally triggered outputs thermostat, as shown in Figure 3. When the DS1720’s temperature meets or exceeds the value stored in the high temperature trip register, the output T DS1720’s measured temperature becomes less than the stored value in the high temperature register, TH. ...
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... NVB = Nonvolatile Memory Busy Flag. 1=write memory is not busy. A copy to E CPU = CPU use bit. If CPU=0, the CLK/ If CPU is 1, the DS1720 will be used with a CPU communicating to it over the 3–wire port, and the operation of the CLK/ pin normal clock in concert with DQ and ...
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... For data inputs, the data must be valid during the rising edge of a clock cycle. Data bits are output on the falling edge of the clock, and remain valid through the rising edge. When reading data from the DS1720, the DQ pin goes to a high impedance state while the clock is high. Taking ...
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... This command stops temperature conversion. No further data is required. This command may be used to halt a DS1720 in continuous conversion mode. After issuing this command, the current temperature measurement will be completed, and then the DS1720 will remain idle until a Start Convert T is issued to resume continuous operation. ...
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... DS1720 COMMAND SET Table 3 INSTRUCTION DESCRIPTION TEMPERATURE CONVERSION COMMANDS Read Temperature Temperature Reads last converted temperature value from temperature register Read Counter Reads value of count remaining from counter Read Slope Reads value of the slope accumulator Start Convert T Initiates temperature conversion Stop Convert T ...
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... FUNCTION EXAMPLE Example: CPU sets up DS1720 for continuous conversion and thermostatic function. DS1720 MODE CPU MODE (3-WIRE DATA (LSB FIRST) 0Ch TCPU issues Write Config command ...
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... READ DATA TRANSFER Figure 4 WRITE DATA TRANSFER Figure DS1720 ...
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... Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. The Dallas Semiconductor DS1720 is built to the highest quality standards and manufactured for long term reliability. All Dallas Semiconductor devices are made using the same quality materials and manufacturing methods. However, the DS1720 is not exposed to environmental stresses, such as burn– ...
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... V , and CONV RST DD = 0.6V 0.4V =2.7V to 5.5V) DD MAX UNITS 750 150 1.75 MHz 500 500 =2.7V to 5.5V) DD MIN TYP MAX 10 50k 10 = GND. 2 memory. = 5.5V. DD DS1720 NOTES UNITS ms Writes Years ...
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... DS1720 TYPICAL THERMOMETER ERROR DS1720 DS1720 ...