Qty 1 Ds75 Ic Thermometer/stat Digital 8-soic Dallas/maxim

US $0.99

Longmont, Colorado, United States
Jan 29th

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DS75 2–Wire Thermal Watchdog FEATURES Temperature measurements require no external components Measures temperatures from –55°C to +125°C. Fahrenheit equivalent is –67°F to +257°F. Thermometer accuracy is ±2.0°C. Thermometer resolution is configurable from nine (default) to 12 bits (0.5°C to 0.0625°C resolution) 9–bit readout mode features a max conversion time of 150 ms. Thermostatic settings are user definable. Data is read from/written via a 2–wire serial interface. (open drain I/O lines). 3–bit addressability Wide power supply range (2.7V – 5.5V). Applications include personal computers, cellular telephones, office equipment, or any thermally sensi- tive system. Pin/software compatible to LM75CIM–x Thermal Watchdog in 9–bit (default) mode. 8–pin 150 mil SOIC package PIN DESCRIPTION SDA – 2–Wire Serial Data Input/Output SCL – 2–Wire Serial Clock GND – Ground O.S. – Thermostat Output Signal A0 – Chip Address Input A1 – Chip Address Input A2 – Chip Address Input VDD– Power Supply Voltage FEATURES The DS75 2–wire thermal watchdog provides 9–bit tem- perature readings which indicate the temperature of the device. Thermostat settings and temperature readings are all communicated to/from the DS75 over a simple 2–wire serial interface. No additional components are required; the device is truly a “temperature–to–digital” converter. The DS75 has three address bits that allow a user to multidrop up to eight sensors along the 2–wire bus, greatly simplifying the bussing of distributed tempera- ture sensing networks. The open–drain thermal alarm output, O.S., becomes active when the temperature of the device exceeds a user–defined temperature TOS. The number of consec- utive faults required to set O.S. active is configurable by the user. The device can also be configured in the inter- rupt or comparator mode, to customize the method which clears the fault condition. For applications that require greater temperature reso- lution, the user can adjust the readout resolution from 9 to 12 bits. This is particularly useful in applications where thermal runaway conditions must be detected quickly. Applications for the DS75 include personal computers/ servers, cellular telephones, office equipment, or any microprocessor–based thermally–sensitive system DETAILED PIN DESCRIPTION PIN SYMBOL DESCRIPTION 1 SDA Data input/output pinfor 2–wire serial communication port. 2 SCL Clock input/output pinfor 2–wire serial communication port. 3 O.S. Thermostat output Becomes active when temperature exceeds TOS. Device configuration defines means to clear over–temperature state. 4 GND Ground pin. 5 A2 Address input pin. 6 A1 Address input pin. 7 A0 Address input pin. 8 VDD Supply Voltage 2.7V – 5.5V input power pin. OVERVIEW A block diagram of the DS75 is shown in Figure 1. The DS75 consists of five major components: 1. Precision temperature sensor 2. Analog–to–digital converter 3. 2–wire interface electronics 4. Data registers 5. Thermostat comparator The factory–calibrated temperature sensor requires no external components. Upon power–up, the DS75 begins temperature conversions with the default resolu- tion of 9 bits (0.5°C resolution). The host can periodi- cally read the value in the temperature register, which contains the last completed conversion. As conver- sions are performed in the background, reading the temperature register does not affect the conversion in progress. In power–sensitive applications, the user can put the DS75 into a shutdown mode, under which the sensor will complete and store the conversion in progress and revert to a low–power standby state. In applications where small incremental temperature changes are criti- cal, the user can change the conversion resolution from 9–bits to 10, 11, or 12. Each additional bit of resolution approximately doubles the conversion time. This is accomplished by programming the configuration register. The configuration register defines the conver- sion state, thermometer resolution/conversion time, active state of the thermostat output, number of consec- utive faults to trigger an alarm condition, and the method to terminate an alarm condition. The user can also program over–temperature (TOS) and under–temperature (THYST) setpoints for thermostatic operation. The power–up state of TOSis 80°C and that for THYSTis 75°C. The result of each temperature con- version is compared with the TOSand THYSTsetpoints. The DS75 offers two modes for temperature control, the comparator mode and the interrupt mode. This allows the user the flexibility to customize the condition that would generate and clear a fault condition. Regardless of the mode chosen, the O.S. output will become active only after the measured temperature exceeds the respective trippoint a consecutive number of times; the number of consecutive conversions beyond the limit to generate an O.S. is programmable. The power–up state of the DS75 is in the comparator mode with a single fault generating an active O.S. Digital data is written to/read from the DS75 via a 2–wire interface, and all communication is MSb first. Multipoint sensing is possible with the DS75 by uniquely setting the 3–bit address of up to 8 parts on the 2–wire bus.

Condition:	New: A brand-new, unused, unopened, undamaged item in its original packaging (where packaging is applicable). Packaging should be the same as what is found in a retail store, unless the item is handmade or was packaged by the manufacturer in non-retail packaging, such as an unprinted box or plastic bag. See the seller's listing for full details. ...	Brand	DALLAS
Model	DS75