DS1721U/T&R+W Maxim Integrated Products, DS1721U/T&R+W Datasheet

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FEATURES § Temperature measurements require no external components with ±1°C accuracy § Measures temperatures from -55°C to +125°C; Fahrenheit equivalent is -67°F to +257°F § Temperature resolution is configurable from (default) bits (0.5°C to 0.0625°C resolution) ...

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ORDERING INFORMATION ORDERING PACKAGE INFORMATION MARKING DS1721S DS1721 DS1721S+ DS1721 (See Note) DS1721S/T&R DS1721 DS1721S+T&R DS1721 (See Note) DS1721U 1721 DS1721U+ 1721 (See Note) DS1721U/T&R 1721 DS1721U+T&R 1721 (See Note) Note: A ”+” symbol will also be marked on the ...

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Each additional bit of resolution approximately doubles the conversion time, so 9-bit conversions can be performed in less than a quarter of a second. This is accomplished by issuing a command protocol to the configuration register recommended that ...

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OPERATION-Measuring Temperature The core of DS1721 functionality is its direct-to-digital temperature sensor. The DS1721 measures temperature through the use of an on-chip temperature measurement technique with an operation range from -55°C to +125°C. The device can be configured to perform ...

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The active state for the totem-pole output is programmable by the user. The power-up default of the DS1721 has TH=80°C, TL=75°C, and the output state active high. Refer to the “OPERATION- Programming” section for instructions in adjusting the thermostat setpoints ...

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R0 Thermometer Resolution Bits. Table 3 below defines the resolution of the digital thermometer, based on the settings of these two bits. There is a direct tradeoff between resolution and conversion time, as depicted in the DC Electrical ...

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If the user does not wish to take advantage of the thermostat capabilities of the DS1721, the 24 bits can be used for general storage of system data that need not be maintained following a power loss. However, the T ...

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DATA TRANSFER ON 2-WIRE SERIAL BUS Figure 5 Figure 6 details how data transfer is accomplished on the two-wire bus. Depending upon the state of the R/ bit, two types of data transfer are possible: W Data transfer from a ...

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SERIAL COMMUNICATION WITH DS1721 Figure ...

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SLAVE ADDRESS st A control byte is the 1 byte received following the START condition from the master device. The control byte consists of a 4-bit control code; for the DS1721, this is set as 1001 binary for read and ...

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Stop Convert T [22h] This command stops temperature conversion. No further data is required. This command may be used to halt a DS1721 in continuous conversion mode. After issuing this command, the current temperature measurement will be completed, stored and ...

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SAMPLE COMMAND SEQUENCE Table 5 Example: After power-up, initiates a temperature conversion, bus master reads temperature BUS MASTER DS1721 MODE MODE ...

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SAMPLE COMMAND SEQUENCE Table 6 Example: Bus master programs the DS1721 for 11-bit conversions in the continuous mode with an active low state for the thermostat output. It then programs TH=50°C and TL=45°C and starts temperature conversions. BUS MASTER DS1721 ...

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ABSOLUTE MAXIMUM RATINGS* Voltage on VDD, Relative to Ground Voltage on any other pin, Related to Ground Operating Temperature Storage Temperature Soldering Temperature * This is a stress rating only and functional operation of the device at these or any ...

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DC ELECTRICAL CHARACTERISTICS: DIGITAL THERMOMETER PARAMETER SYMBOL DS1721 T ERR Thermometer Error Resolution Conversion Time t CONVT AC ELECTRICAL CHARACTERISTICS: 2-WIRE INTERFACE PARAMETER SYMBOL SCL Clock f SCL Frequency Bus Free Time Between a STOP t BUF and START Condition ...

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Capacitive Load for C each Bus Line Input Capacitance C NOTES: 1. All voltages are referenced to ground. 2. I/O pins of fast mode devices must not obstruct the SDA and SCL lines specified with T ...

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TYPICAL DS1721 THERMOMETER PERFORMANCE CURVE Figure 8 DS1721 ...