Rainbow-electronics DS1621 User Manual

1 of 16 102299FEATURES§ Temperature measurements require noexternal components§ Measures temperatures from –55°C to+125°C in 0.5°C increments. Fahr

DS1621 10 of 16 102299COMMAND SETData and control information is read from and written to the DS1621 in the format shown in Figure 5. Towrite to the D

DS1621 11 of 16 102299measurement will be completed and the DS1621 will remain idle until a Start Convert T is issued toresume continuous operation.DS

DS1621 12 of 16 102299MEMORY FUNCTION EXAMPLEExample: Bus master sets up DS1621 for continuous conversion and thermostatic function.BUS MASTERMODEDS16

DS1621 13 of 16 102299ABSOLUTE MAXIMUM RATINGS*Voltage on Any Pin Relative to Ground –0.5V to +7.0VOperating Temperature –55°C to +125°CStorage Temper

DS1621 14 of 16 102299AC ELECTRICAL CHARACTERISTICS (-55°C to +125°C; VDD=2.7V to 5.5V)PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTESTemper

DS1621 15 of 16 102299NOTES:1. All voltages are referenced to ground.2. I/O pins of fast mode devices must not obstruct the SDA and SCL lines if VDD

DS1621 16 of 16 102299TYPICAL PERFORMANCE CURVEDS1621 DIGITAL THERMOMETER AND THERMOSTATTEMPERATURE READING ERRORTEMPERATURE (deg. C)

DS1621 2 of 16 102299DETAILED PIN DESCRIPTION Table 1PIN SYMBOL DESCRIPTION1 SDA Data input/output pin for 2-wire serial communication port.2 SCL Cloc

DS1621 3 of 16 102299DS1621 FUNCTIONAL BLOCK DIAGRAM Figure 1STATUS REGISTER &CONTROL LOGICTEMPERATURE SENSORHIGH TEMP TRIGGER, THLOW TEMP TRIGGER

DS1621 4 of 16 102299TEMPERATURE MEASURING CIRCUITRY Figure 2TEMPERATURE/DATA RELATIONSHIPS Table 2TEMPERATURE DIGITAL OUTPUT(Binary)DIGITAL OUTPUT(He

DS1621 5 of 16 102299Higher resolutions may be obtained by reading the temperature and truncating the 0.5°C bit (the LSB)from the read value. This val

DS1621 6 of 16 102299THF = Temperature High Flag. This bit will be set to “1” when the temperature is greater than orequal to the value of TH. It will

DS1621 7 of 16 102299Data valid: The state of the data line represents valid data when, after a START condition, the data lineis stable for the durati

DS1621 8 of 16 102299The master device generates all of the serial clock pulses and the START and STOP conditions. Atransfer is ended with a STOP con

DS1621 9 of 16 1022992-WIRE SERIAL COMMUNICATION WITH DS1621 Figure 5