DS1921G-F5N MAXIM [Maxim Integrated Products], DS1921G-F5N Datasheet
DS1921G-F5N
Related parts for DS1921G-F5N
DS1921G-F5N Summary of contents
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... DS1921G-F5# -40°C to +85°C DS1921G-F5N# -40°C to +85°C #Denotes a RoHS-compliant device that may include lead(Pb) that is exempt under the RoHS requirements. A NIST traceability certificate is available for the DS1921G-F5N. See Application Note 4629 for details. Examples of Accessories PART ACCESSORY DS9096P Self-Stick Adhesive Pad ...
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Thermochron iButton ABSOLUTE MAXIMUM RATINGS IO Voltage Range Relative to GND ..........................-0.5V to +6V IO Sink Current....................................................................20mA * Storage or operation above +50°C significantly reduces battery life. Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to ...
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ELECTRICAL CHARACTERISTICS (continued +2.8V to +5.25V -40°C to +85°C.) PUP A PARAMETER SYMBOL IO PIN: 1-Wire WRITE Write-Zero Low Time (Notes 1, 12, 13) Write-One Low Time (Notes 1, 13) IO PIN: 1-Wire READ Read Low ...
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... Meets UL 913, 5th Ed., Rev. 1997-02-24; Intrinsically Safe Apparatus, approval under Entity Concept for use in SAFETY Class I, Division 1, Group and D Locations. 4 _______________________________________________________________________________________ OVERDRIVE SPEED (µs) STANDARD SPEED (µs) MIN MAX MIN 7 (undefined) 65 540 DS1921G VALUES OVERDRIVE SPEED (µs) MAX MIN MAX (undefined) 8* (undefined) 640 1.1 6 270 7.5 32 120 8.5 15 ...
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Minimum Product Lifetime vs. Temperature at Different Sample Rates 11.00 10.00 9.00 8.00 7.00 6.00 5.00 4.00 EVERY MINUTE 3.00 NO SAMPLES 2.00 EVERY 3 MINUTES OSCILLATOR OFF 1.00 ...
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Thermochron iButton Minimum Product Lifetime vs. Sample Rate at Different Temperatures 11.00 10.00 9.00 8.00 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0.00 1 2.0 1.5 1.0 0.5 0 -0.5 -1.0 -1.5 -2.0 -40 -30 6 _______________________________________________________________________________________ 10 MINUTES BETWEEN ...
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... Application Note 4126: Understanding the IP (Ingress Protection) Ratings of iButton Data Loggers and Capsule ). Figure 1 shows the relationships between the major control and memory sections of the DS1921G. The device has seven main data components: 64-bit lasered ROM; 256-bit scratchpad; 4096-bit general- purpose SRAM; 256-bit register page of timekeeping, control, and counter registers ...
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... ROM function commands, and 2) if the battery is exhausted for any reason, the ROM may still be read normally. The remaining circuitry of the DS1921G is solely operated by battery energy consequence, if the battery is exhausted, all memory data is lost including the data of the last mission, and no new mission can be started ...
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... X Figure 4. 1-Wire CRC Generator 64-Bit Lasered ROM Each DS1921G contains a unique ROM code that is 64 bits long. The first 8 bits are a 1-Wire family code. The next 48 bits are a unique serial number. The last 8 bits are a cyclic redundancy check (CRC) of the first 56 bits (see Figure 3 for details) ...
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... Thermochron iButton 32-BYTE INTERMEDIATE STORAGE SCRATCHPAD ADDRESS 0000h to 01FFh 0200h to 021Fh 0220h to 027Fh 0280h to 07FFh 0800h to 087Fh 0880h to 0FFFh 1000h to 17FFh 1800h to 1FFFh Figure 5. Memory Map ADDRESS BIT 7 BIT 6 BIT 5 0200h 0 10 Seconds 0201h 0 10 Minutes 20 Hour 0202h 0 12/24 AM/PM 0203h 0 0 0204h ...
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... The contents of the time, calendar, and alarm registers are in the binary-coded decimal (BCD) format. The RTC of the DS1921G can run in either 12hr or 24hr mode. Bit 6 of the Hours register (address 0202h) is defined as the 12hr or 24hr mode select bit. When high, the 12hr mode is selected ...
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... The DS1921G also contains an RTC alarm function. The RTC Alarm registers are located in registers 0207h to 020Ah. The most significant bit of each of the alarm registers is a mask bit. When all the mask bits are logic 0, an alarm occurs once per week when the values ...
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... Temperature Logging and Histogram section), the data in these bins is of lim- ited value. For this reason the specified temperature range of the DS1921G is considered to begin at code 04h and end at code F7h, which corresponds to his- togram bins 1 to 61. ...
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... For a typical mission, the Mission Start Delay mission is too long for a single DS1921G to store all temperature readings at the selected sample rate, one can use several devices, staggering the Mission Start Delay to record the full period ...
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... The memory has to be cleared in order for a mission to start. Bit 5: Mission in Progress (MIP). If this bit reads 1, the DS1921G has been set up for a mission and this mis- sion is still in progress. A mission is started if the EM bit of the Control register (address 20Eh and a nonze- ro value is written to the Sample Rate register, address 20Dh ...
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... Low Byte Center Byte High Byte Temperature Logging and Histogram Once set up for a mission, the DS1921G logs the tem- perature measurements simultaneously byte after byte in the data-log memory as well as in histogram form in the histogram memory. The data-log memory is able to store 2,048 temperature values measured at equidis- tant time points ...
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... As long as the temperature values stay within the tolerance band (i.e., are higher than the low threshold and lower than the high threshold), the DS1921G does not record any temperature alarm. If the temperature during a mission reaches or exceeds either threshold, the DS1921G generates an alarm and ...
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... Before the device can perform this function, it needs to be configured. This procedure is called missioning. First, the DS1921G must have its RTC set to a valid time and date. This reference time can be UTC (also called GMT, Greenwich Mean Time) or any other time stan- dard that was chosen for the application ...
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... Writing data to the scratchpad clears this flag. Writing with Verification To write data to the DS1921G, the scratchpad must be used as intermediate storage. First, the master issues the Write Scratchpad command to specify the desired target address, followed by the data to be written to the scratchpad ...
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... DS1921G. An example on how to use these and other functions to set up the DS1921G for a mission is includ the Mission Example: Prepare and Start a New Mission section. The communication between master and DS1921G takes place either at standard speed (default overdrive speed ( ...
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... TA1 and TA2, the E/S byte, and the scratchpad data starting at the target address. After the CRC is read, the bus master reads logical “1”s from the DS1921G until a reset pulse is issued. Copy Scratchpad [55h] This command is used to copy data from the scratch- pad to the writable memory sections ...
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... CONTROL FUNCTION COMMAND FLOWCHART (FIGURE 13) 0Fh N WRITE SCRATCHPAD? Y DS1921G SETS EMCLR = 0 MASTER Tx TA1 [T7:T0], TA2 [T15:T8] DS1921G SETS SCRATCHPAD OFFSET = [T4:T0] AND CLEARS (PF, AA) MASTER Tx DATA BYTE TO SCRATCHPAD OFFSET DS1921G DS1921G SETS [E4:E0] = INCREMENTS SCRATCHPAD OFFSET SCRATCHPAD OFFSET Y MASTER Tx RESET? N SCRATCHPAD N OFFSET = 11111b? PARTIAL Y BYTE WRITTEN ...
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... N CLEAR MEMORY Y N EMCLR = 1? Y DS1921G CLEARS MISSION TIMESTAMP, MISSION SAMPLES COUNTER, MISSION START DELAY, SAMPLE RATE REGISTER DS1921G CLEARS ALARM TIMESTAMPS AND DURATIONS DS1921G CLEARS HISTOGRAM MEMORY DS1921G SETS MEMCLR = 1 DS1921G ADDRESS COUNTER DS1921G SETS EMCLR = 0 N MASTER Tx RESET? ...
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... Figure 10c. Memory/Control Function Flowchart 24 ______________________________________________________________________________________ 44h CONVERT N TEMPERATURE? Y TEMPERATURE DS1921G SETS CONVERSION PROCESS EMCLR = 0 DS1921G SETS Y MISSION IN TCB = 0 PROGRESS? N DS1921G PERFORMS A TEMPERATURE CONVERSION DS1921G STARTS TEMPERATURE CONVERSION PROCESS DS1921G COPIES RESULT TO ADDRESS 0211h DS1921G SETS N MASTER TCB = 1 Tx RESET? Y END OF PROCESS N MASTER Tx RESET? Y ...
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... Next, the Mission Start Delay Counter starts decrementing every minute until it is down to 0. Now the DS1921G waits until the next minute boundary and starts the logging process, which as its first action copies the applicable RTC reg- isters to the Mission Timestamp register ...
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... Thermochron iButton MISSION START PROCESS Y MIP = 1? N DS1921G SETS MIP = MEMCLR = NEW SAMPLE RATE = 0? N DS1921G COPIES NEW SAMPLE RATE FROM SCRATCHPAD TO SAMPLE RATE REGISTER DS1921G SETS MIP = 1; MEMCLR = 0 Y START DELAY COUNTER = MIP = 1? Y DS1921G WAITS UNTIL NEXT ...
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... With the DS1921G the bus must be left low for no longer than 15µs at overdrive speed to ensure that no DS1921G on the 1-Wire bus performs a reset. The DS1921G communicates properly when used in conjunction with a DS2480B or DS2490 1-Wire driver and adapters that are based on these driver chips ...
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... The presence pulse lets the bus master know that the DS1921G is on the bus and is ready to operate. For more details, see the 1-Wire Signaling section. ROM Function Commands Once the bus master has detected a presence, it can issue one of the seven ROM function commands ...
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... BIT 63 MATCH? BIT 63 MATCH MEMORY FUNCTIONS FLOWCHART (FIGURE 10) FROM FIGURE 13b ECh TO FIGURE 13b N N CONDITIONAL SEARCH COMMAND CONDITION MET? Y DS1921G Tx BIT DS1921G Tx BIT MASTER Tx BIT BIT 0 MATCH? Y DS1921G Tx BIT DS1921G Tx BIT MASTER Tx BIT BIT 1 MATCH? Y DS1921G Tx BIT 63 ...
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Thermochron iButton TO FIGURE 13a FROM FIGURE 13a FROM FIGURE 13a TO FIGURE 13a ***ALWAYS TO BE TRANSMITTED AT OVERDRIVE SPEED. Figure 13b. ROM Functions Flowchart 30 ______________________________________________________________________________________ CCh 3Ch N N SKIP ROM OVERDRIVE- OVERDRIVE- COMMAND? SKIP ROM? MATCH ...
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... The initialization sequence required to begin any com- munication with the DS1921G is shown in Figure 14. A reset pulse followed by a presence pulse indicates the DS1921G is ready to receive data, given the correct ROM and memory function command. If the bus master ...
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... When responding with a 1, the DS1921G does not hold the data line low at all, and the voltage starts rising as soon ...
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... IHMASTER ILMAX RESISTOR READ-DATA TIME SLOT PUP V IHMASTER ILMAX RESISTOR Figure 15. Read/Write Timing Diagram ______________________________________________________________________________________ Thermochron iButton ε t SLOT MASTER t W0L t SLOT MASTER t MSR MASTER SAMPLING WINDOW δ t SLOT MASTER ε t REC t REC DS1921G 33 ...
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... CRC generator and then shifting in the command code, the target addresses TA1 and TA2, the E/S byte, and the scratchpad data starting at the target address. The DS1921G transmits this CRC only if the reading continues through the end 1ST ...
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... RST PD Select RM TA <data to EOM> Read Memory (Invalid Address) RST PD Select loop Reading reserved pages 20 through through 127 or pages 192 and higher (beyond data-log memory) results in 00h bytes. ______________________________________________________________________________________ Thermochron iButton DESCRIPTION 1-Wire Communication Examples CRC-16 FF loop RST PD CRC-16 ...
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... Start a New Mission Assumption: The previous mission has ended. To end an ongoing mission write the MIP bit in the Status regis- ter to 0. The preparation of a DS1921G for a mission including the start of the mission requires up to four steps: 36 ______________________________________________________________________________________ 1-Wire Communication Examples (continued) < ...
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... Let the actual time be 15:30:00 hours on Monday, the 1st of April in 2002. This results in the following data to be writ- ten to the RTC registers: ADDRESS 200h DATA 00h With only a single DS1921G connected to the bus master, the communication of step follows: MASTER MODE DATA (LSB FIRST ...
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... Clear Memory command is issued. Wait 500µs after issuing the Clear Memory command before proceeding to step 3. This results in the following data to be written to the Status register: ADDRESS DATA With only a single DS1921G connected to the bus master, the communication of step follows: MASTER MODE DATA (LSB FIRST) Tx ...
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... Writing through address locations 20Fh to 211h is faster than accessing the Mission Start Delay register in a separate cycle. The write attempt has no effect on the contents of these registers. With only a single DS1921G connected to the bus master, the communication of step follows: MASTER MODE ...
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... The sample rate is once every 10min, allowing the mission to last days. This results in the following data to be written to the special function registers: ADDRESS DATA With only a single DS1921G connected to the bus master, the communication of step follows: MASTER MODE DATA (LSB FIRST) Tx ...
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... Thermochrom IO NOTE: THE DS1921G-F5N# HAS A #F5N SUFFIX. GND ______________________________________________________________________________________ Thermochron iButton For the latest package outline information and land patterns (footprints www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. ...
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... Updated UL certificate reference; deleted from the t 4/11 table; applied note 13 to the t details to Electrical Characteristics table notes 7, 13, and 14 DS1921G-F5N# part number added to the Ordering Information; branding information updated in the 9/11 Pin Configuration Added terminology updates for consistency with similar products; added more details to the Parasite ...