DS1922E-F5# Maxim Integrated Products, DS1922E-F5# Datasheet
DS1922E-F5#
Specifications of DS1922E-F5#
Related parts for DS1922E-F5#
DS1922E-F5# Summary of contents
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... First Applies Voltage ♦ Meets UL 913 (4th Edit.); Intrinsically Safe Apparatus: Approved Under Entity Concept for Use in Class I, Division 1, Group and D Locations* PART DS1922E-F5# # Denotes a RoHS-compliant device that may include lead(Pb) that is exempt under the RoHS requirements. DS9093RA DS9107 DS9490B Pin Configuration appears at end of data sheet. ...
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... Rising-Edge Hold-Off Time Time Slot Duration (Note 2) I/O PIN 1-Wire RESET, PRESENCE-DETECT CYCLE Reset Low Time (Note 2) Presence-Detect High Time 2 _______________________________________________________________________________________ Junction Temperature ......................................................+150°C Storage Temperature Range............................-25°C to +140°C* CONDITIONS T DS1922E (Note (Notes 2, 3) PUP C (Note I/O pin PUP ...
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High-Temperature Logger iButton with 8KB ELECTRICAL CHARACTERISTICS (continued 3.0V to 5.25V.) PUP PARAMETER SYMBOL Presence-Detect Fall Time (Note 13) Presence-Detect Low Time Presence-Detect Sample Time (Note 2) I/O PIN 1-Wire WRITE Write-Zero Low Time (Notes 2, 14) Write-One ...
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High-Temperature Logger iButton with 8KB Data-Log Memory Note 1: Operation above +125°C is restricted to mission operations only. Communication and 1-Wire pin specifications are not specified for operation above +125°C. Note 2: System requirement. Note 3: Maximum allowable pullup resistance ...
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... MAX MIN MAX 7 (undefined 240 8 24 120 6 16 RTC ACCURACY (TYPICAL TEMPERATURE (°C) Data-Log Memory DS1922E VALUES STANDARD SPEED OVERDRIVE SPEED (μs) (μs) MIN MAX MIN * 65 (undefined) 9.5 (undefined) 690 720 287 7 60 120 7.5 RTC Accuracy 105 115 ...
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... The remaining circuitry of the DS1922E is sole- Overview ly operated by battery energy. Each DS1922E 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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... LITHIUM 32.768kHz OSCILLATOR THERMAL SENSE Figure 1. Block Diagram _______________________________________________________________________________________ ROM 64-BIT FUNCTION LASERED CONTROL ROM MEMORY FUNCTION CONTROL DS1922E GENERAL-PURPOSE SRAM (512 BYTES) INTERNAL TIMEKEEPING, REGISTER PAGES CONTROL REGISTERS, (64 BYTES) AND COUNTERS USER MEMORY ADC (64 BYTES) CONTROL DATA-LOG MEMORY LOGIC 8KB ...
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... STAGE Figure 4. 1-Wire CRC Generator 8 _______________________________________________________________________________________ OTHER DEVICES DS1922E AVAILABLE COMMANDS: DATA FIELD AFFECTED: READ ROM 64-BIT ROM, RC-FLAG MATCH ROM 64-BIT ROM, RC-FLAG SEARCH ROM 64-BIT ROM, RC-FLAG CONDITIONAL SEARCH ROM 64-BIT ROM, RC-FLAG, ALARM FLAGS, SEARCH CONDITIONS SKIP ROM ...
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... High-Temperature Logger iButton with 8KB Figure 5 shows the DS1922E memory map. Pages contain 512 bytes of general-purpose SRAM. The various registers to set up and control the device fill pages 16 and 17, called register pages 1 and 2 (see Figure 6 for details). Pages 18 and 19 can be used as extension of the general-purpose memory. The data-log logging memory starts at address 1000h (page 128) and extends over 256 pages ...
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... The left entry in the ACCESS column is valid between missions. The right entry shows the applicable access type while a mission is in progress. Figure 6. DS1922E Register Pages Map 10 ______________________________________________________________________________________ BIT 5 BIT 4 BIT 3 BIT 2 Single Seconds Single Minutes 10 Hour ...
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... Function; All These Bytes Read 00h) … 023Fh * The left entry in the ACCESS column is valid between missions. The right entry shows the applicable access type while a mission is in progress. Figure 6. DS1922E Register Pages Map (continued) ______________________________________________________________________________________ BIT 5 BIT 4 BIT 3 BIT 2 ...
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... These bits always read 0 regardless of how they are written. The number representation of the RTC registers is binary-coded decimal (BCD) format. The DS1922E’s RTC 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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... High-Temperature Logger iButton with 8KB Temperature Conversion The DS1922E’s temperature range begins at +15°C and ends at +140°C. Temperature values are repre- sented 16-bit unsigned binary number with a resolution of 0.5°C in 8-bit mode and 0.0625°C in 16-bit mode. The higher temperature byte TRH is always valid. In 16-bit mode, only the three highest bits of the lower byte TRL are valid ...
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... BIT minimize the power consumption of a DS1922E, the RTC oscillator should be turned off when the device is not in use. The oscillator on/off bit is located in the RTC Control register. This register also includes the EHSS bit, which determines whether the sample rate is speci- fied in seconds or minutes ...
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... Note: During a mission, there is only read access to this register. Bits 6 and 7 have no function. They always read 1 and cannot be written to 0. Bits 1 and 3 control functions that are not available with the DS1922E. Bit 1 must be set to 0. Under this condition the setting of bit 3 becomes a “don’t care.” ...
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... Note: There is only read access to this register. Bits have no function. They always read 1. Bits 2 and 3 have no function with the DS1922E. They always read 0. The alarm status bits are cleared simultaneously when the Clear Memory Function is invoked. See memory and control functions for details. ...
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... For a typical mission, the Mission Start Delay mission is too long for a single DS1922E to store all readings at the selected sample rate, one can use sev- eral devices and set the Mission Start Delay for the sec- ond device to start recording as soon as the memory of the first device is full, and so on ...
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... BIT 4 BIT 3 EPW Other Indicators The DS1922E is designed to use two passwords that control read access and full access. Reading from or writing to the scratchpad as well as the forced conver- sion command does not require a password. The pass- word must be transmitted immediately after the command code of the memory or control function ...
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... FP0, FP1…FP62, FP63. It affects the functions Read Memory with CRC, Copy Scratchpad, Clear Memory, Start Mission, and Stop Mission. The DS1922E executes the command only if the password transmitted by the master was correct or if password checking is not enabled. Due to the special behavior of the write-access logic, the Password Control register and both passwords must be written at the same time ...
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... Before the device can perform this func- tion, it needs to be set up properly. This procedure is called missioning. First, the DS1922E must have its RTC set to a valid time and date. This reference time can be the local time, or, when used inside of a mobile unit, UTC (also called GMT, Greenwich Mean Time), or any other time stan- dard that was agreed upon ...
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... EHSS bit. If the Start Upon Temperature Alarm mode is chosen (SUTA = 1) and temperature logging is enabled (ETL = 1), the DS1922E first waits until the start delay is over. Then the device wakes up in intervals as specified by the sample rate and EHSS bit and measures the tem- perature ...
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... Figure 9 shows the protocols necessary for accessing the memory and the special function registers of the DS1922E. An example on how to use these and other functions to set up the DS1922E for a mission is includ the Mission Example: Prepare and Start a New Mission section. The communication between the mas- ...
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... CRC generator and then shift- ing in the contents of the data memory page. After the 16-bit CRC of the last page is read, the bus master receives logic 1s from the DS1922E until a reset pulse is issued. The Read Memory with CRC command sequence can be ended at any point by issuing a reset pulse ...
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... FLOWCHART (FIGURE 11) 0Fh N WRITE SCRATCHPAD? Y MASTER Tx TA1 [T7:T0] MASTER Tx TA2 [T15:T8] DS1922E SETS SCRATCHPAD OFFSET = [T4:T0] AND CLEARS (PF, AA) MASTER Tx DATA BYTE TO SCRATCHPAD OFFSET DS1922E DS1922E SETS [E4:E0] = INCREMENTS SCRATCHPAD OFFSET SCRATCHPAD OFFSET Y MASTER Tx RESET SCRATCHPAD OFFSET = 11111b? PARTIAL Y BYTE WRITTEN? Y ...
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... DS1922E ALARM FLAGS INCREMENTS ADDRESS COUNTER DS1922E SETS MEMCLR = MASTER Tx RESET MASTER Rx "1"s N Data-Log Memory 55h N N FORCED CONVERSION? Y MASTER Tx FFh DUMMY BYTE Y MISSION IN PROGRESS DS1922E PERFORMS A TEMPERATURE CONVERSION DS1922E COPIES RESULT TO Y ADDRESS 020C/Dh N MASTER Tx RESET FIGURE 9c FROM FIGURE 9c 25 ...
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... START DELAY COUNTER = 0? MASTER Tx N DS1922E WAITS FOR 1 MINUTE PASSWORD DS1922E DECREMENTS ACCEPTED? START DELAY COUNTER Y MISSION IN PROGRESS? SUTA = DS1922E SETS WFTA = 1 DS1922E WAITS ONE Y SAMPLE PERIOD MIP = 1, Y MIP = 0? N DS1922E PERFORMS 8-BIT TEMPERATURE CONVERSION TEMPERATURE ALARM DS1922E SETS WFTA = 0 ...
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... Status register reads 1. During a mission there is only read access to the register pages. Stop Mission with Password [33h] The DS1922E uses a control function command to stop a mission. Only a mission that is in progress can be stopped. After the command code, the master must transmit the 64-bit full-access password followed by a FFh dummy byte ...
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High-Temperature Logger iButton with 8KB Data-Log Memory Memory Access Conflicts While a mission is in progress or while the device is waiting for a temperature alarm to start a mission, peri- odically a temperature sample is taken and logged. This ...
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... With the DS1922E the bus must be left low for no longer than 12µs at overdrive to ensure that no DS1922E on the 1-Wire bus performs a reset. The DS1922E 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 DS1922E is on the bus and is ready to operate. For more details, see the 1-Wire Signaling section. 1-Wire ROM Function Commands ...
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... AND result). The Overdrive-Match ROM command followed by a 64-bit ROM sequence transmitted at overdrive speed allows the bus master to address a specific DS1922E on a multidrop bus and to simultaneously set it in Overdrive Mode. Only the DS1922E that exactly match- es the 64-bit ROM sequence responds to the subse- quent memory/control function command ...
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... DS1922E Tx BIT 0 MASTER Tx BIT 0 MASTER Tx BIT BIT 0 MATCH? BIT 0 MATCH? BIT 0 MATCH DS1922E Tx BIT 1 DS1922E Tx BIT 1 MASTER Tx BIT 1 DS1922E Tx BIT 1 DS1922E Tx BIT 1 MASTER Tx BIT 1 MASTER Tx BIT BIT 1 MATCH? BIT 1 MATCH? BIT 1 MATCH DS1922E Tx BIT 63 DS1922E Tx BIT 63 MASTER Tx BIT 63 DS1922E Tx BIT 63 DS1922E Tx BIT 63 ...
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High-Temperature Logger iButton with 8KB TO FIGURE 11a CCh FROM FIGURE 11a SKIP ROM COMMAND FROM FIGURE 11a TO FIGURE 11a NOTE: THE OD FLAG REMAINS THE DEVICE WAS ALREADY AT OVERDRIVE SPEED ...
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... ILMAX determining a logical level, not triggering any events. The initialization sequence required to begin any com- munication with the DS1922E is shown in Figure 12. A reset pulse followed by a presence pulse indicates the DS1922E 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 DS1922E does not hold the data line low at all, and the voltage starts rising as soon δ (rise time) on one side and the inter- ...
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... W1L V PUP V IHMASTER ILMAX RESISTOR WRITE-ZERO TIME SLOT V PUP V IHMASTER ILMAX RESISTOR READ-DATA TIME SLOT PUP V IHMASTER ILMAX RESISTOR Figure 13. Read/Write Timing Diagrams 36 ______________________________________________________________________________________ ε t SLOT MASTER t W0L t SLOT MASTER t MSR MASTER SAMPLING WINDOW δ t SLOT MASTER ε t REC t REC DS1922E ...
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... X Figure 15. CRC-16 Hardware Description and Polynomial CRC Generation The DS1922E uses two types of CRCs. One CRC is an 8-bit type and is stored in the most significant byte of the 64-bit ROM. The bus master can compute a CRC value from the first 56 bits of the 64-bit ROM and com- pare it to the value stored within the DS1922E to deter- mine if the ROM data has been received error-free ...
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... High-Temperature Logger iButton with 8KB Data-Log Memory ing in the command code, the target addresses TA1 and TA2, and all the data bytes. The DS1922E transmits this CRC only if the data bytes written to the scratchpad include scratchpad ending offset 11111b. The data can start at any location within the scratchpad ...
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High-Temperature Logger iButton with 8KB Command-Specific 1-Wire Communication Protocol—Color Codes Master-to-Slave Slave-to-Master Write Scratchpad, Reaching the End of the Scratchpad (Cannot Fail) RST PD Select WS TA <Data to EOS> Read Scratchpad (Cannot Fail) RST PD Select RS TA-E/S <Data ...
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High-Temperature Logger iButton with 8KB Data-Log Memory Forced Conversion RST PD Select FC FFh FF Loop To read the result and to verify success, read the addresses 020Ch to 020Fh (results) and the device samples counter at address 0223h to ...
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... Alarm Controls (Response to Conditional Search) • General Mission Parameters (e.g., Channels to Log and Logging Format, Rollover, Start Mode) • Mission Start Delay The following data sets up the DS1922E for a mission that logs temperature using 8-bit format. EXAMPLE VALUES Time Date ...
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High-Temperature Logger iButton with 8KB Data-Log Memory With only a single device connected to the bus master, the communication of step 2 looks like this: MASTER MODE ...
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... Software Correction Algorithm for Temperature The correction algorithm described in the DS1922L/ DS1922T data sheet does not apply to the DS1922E. If attempted, the corrected result is generally less accu- rate than the raw temperature data read from the device. Therefore, with the DS1922E the memory pages 18 and 19 are available as additional user memory ...
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... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 44 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2009 Maxim Integrated Products DESCRIPTION Maxim is a registered trademark of Maxim Integrated Products, Inc ...