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General Description

The DS1682 is an integrated elapsed-time recorder con-

taining a factory-calibrated, temperature-compensated

RC time base that eliminates the need for an external

crystal. Using EEPROM technology to maintain data in

the absence of power, the DS1682 requires no backup

power source. The DS1682 detects and records the num-

ber of events on the EVENT pin and the total cumulative

event time since the DS1682 was last reset to 0. The

ALARM pin alerts the user when the total time accu-

mulated equals the user-programmed alarm value. The

polarity of the open-drain ALARM pin can be programmed

to either drive low or to become high impedance upon an

alarm condition. The DS1682 is ideal for applications that

monitor the total amount of time that a device has been

in operation and/or the number of uses since inception of

service, repair, or the last calibration.

Applications

● High-Temp, Rugged, Industrial Applications Where

Vibration or Shock Could Damage a Quartz Crystal

● Any System Where Time-of-Use is Important

(Warranty Tracking)

Benets and Features

● Records the Total Time That the Event Input Has

Been Active and the Number of Events That Have

Occurred

● 32-Bit, Nonvolatile, Elapsed Time Counter (ETC)

Monitors Event Duration with Quarter-Second

Resolution and Provides 34 Years of Total Time

Accumulation

● Programmable Elapsed Time ALARM Output

● Nonvolatile, 17-Bit Event Counter Records the Total

Number of Times an Event has Occurred

● Calibrated, Temperature-Compensated RC Time

Base Accurate to 2% Typical

● 10 Bytes of EEPROM User Memory

● Write Disable Function to Prevent the Memory from

Being Changed or Erased

● 2-Wire Serial Communication

● Wide 2.5V to 5.5V Power-Supply Range

● Useful in Time-of-Use Warranty, Calibration, Repair,

and Maintenance Applications

Ordering Information appears at end of data sheet.

For related parts and recommended products to use with this part, refer

to www.maximintegrated.com/DS1682.related.

Figure 1. Block Diagram

SERIAL INTERFACE

EVENT COUNTER

CONTROL

LOGIC AND

EVENT

GLITCH

FILTER

OSCILLATOR

AND DIVIDER

SCL

SDA

ALARM

EVENT

DS1682

ELAPSED TIME

COUNTER (ETC)

USER, CONTROL, AND

CONFIGURATION

REGISTERS

ALARM REGS

AND

COMPARE LOGIC

EEPROM ARRAY

DS1682 Total-Elapsed-Time Recorder

with Alarm

19-6835; Rev 1; 11/13

Summary of content (14 pages)

PAGE 1
DS1682 Total-Elapsed-Time Recorder with Alarm General Description The DS1682 is an integrated elapsed-time recorder containing a factory-calibrated, temperature-compensated RC time base that eliminates the need for an external crystal. Using EEPROM technology to maintain data in the absence of power, the DS1682 requires no backup power source. The DS1682 detects and records the number of events on the EVENT pin and the total cumulative event time since the DS1682 was last reset to 0.
PAGE 2
DS1682 Total-Elapsed-Time Recorder with Alarm Absolute Maximum Ratings Lead Temperature (soldering, 10s).................................. +300°C Soldering Temperature (reflow)........................................+260°C Voltage Range on Any Pin Relative to Ground .......-0.3V to +6V Operating Temperature Range............................ -40°C to +85°C Storage Temperature Range.............................
PAGE 3
DS1682 Total-Elapsed-Time Recorder with Alarm AC Electrical Characteristics (VCC = 2.5V to 5.5V, TA = -40°C to +85°C, unless otherwise noted.) PARAMETER SYMBOL CONDITIONS EEPROM Endurance EE (Note 2) EEPROM Write Time tEW (Notes 1, 3, 4) EEPROM Transfer to RAM tER (Notes 1, 5) ALARM Output Active-Low Pulse Width tSL ALARM Output Active-High Pulse Width MIN TYP 150 MAX UNITS 50k writes 300 ms 1 ms (Note 1) 62.5 ms tSH (Note 1) 437.
PAGE 4
DS1682 Total-Elapsed-Time Recorder with Alarm Timing Diagram SDA tBUF tF tLOW tHD:STA tSP SCL tHD:STA tHIGH tR tHD:DAT STOP START tSU:STA tSU:STO tSU:DAT REPEATED START NOTE: TIMING IS REFERENCED TO VIL(MAX) AND VIH(MIN). Note 1: Typical values are at TA = +25°C, VCC = 4.0V. Note 2: The elapsed time and event counters are backed by three EEPROM arrays, which are used sequentially, allowing up to 3 x EE.
PAGE 5
DS1682 Total-Elapsed-Time Recorder with Alarm Pin Configuration TOP VIEW + 8 VCC 7 N.C. 3 6 SDA 4 5 SCL EVENT 1 N.C. 2 ALARM GND DS1682 SO (150 mils) Pin Description PIN NAME FUNCTION 1 EVENT Event Input. The EVENT pin is the input the DS1682 monitors to determine when an event occurs. When the pin is pulled high, the contents of the EEPROM are transferred to the ETC and the oscillator starts. The ETC begins to count in quarter-second increments.
PAGE 6
DS1682 Total-Elapsed-Time Recorder with Alarm Operation The block diagram in Figure 1 shows the relationship between the major functional blocks, the serial interface, and the EEPROM memory section of the DS1682. Upon power-up, the DS1682 transfers the contents of the EEPROM into the counters and memory registers where the data can be read and written through the serial interface.
PAGE 7
DS1682 Total-Elapsed-Time Recorder with Alarm Table 1.
PAGE 8
DS1682 Total-Elapsed-Time Recorder with Alarm Event Logging Device Setup 1) The RC oscillator starts. The following is a typical sequence: 2) The alarm, ETC, and event counter are transferred from EEPROM to RAM. 1) Write the configuration register, alarm registers, and user memory to the desired values. 3) Note: Reading the RAM during the transfer results in invalid data. 2) Write-protect the alarm, ETC, and event counter registers with the write disable command if needed.
PAGE 9
DS1682 Alarm The alarm register is a 32-bit register that holds time in quarter-second resolution. When a nonzero number is programmed into the alarm register, the ALARM function is enabled and the DS1682 monitors the values in the ETC for the programmed value in the alarm register. When the ETC matches the alarm value, the alarm flag is set. EEPROM Array When power is applied, the contents of the EEPROM are transferred to the configuration register, alarm register, ETC, event counter, and user memory.
PAGE 10
DS1682 Total-Elapsed-Time Recorder with Alarm Configuration Register MSB LSB BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 BIT 0 0 AF WDF WMDF AOS RE AP ECMSB Note: The configuration register is not stored in EEPROM until an event becomes inactive. RE does not need to be stored in EEPROM to reset the device. Bit 6: Alarm Flag (AF). The alarm flag is set to a 1 when the ETC value matches the alarm register. Once the AF bit is set to a 1, it cannot be set to a 0. This bit is read-only.
PAGE 11
DS1682 Total-Elapsed-Time Recorder with Alarm defines a START condition. User Memory There are 10 bytes of user-programmable, EEPROM memory. Once the write-memory disable flag is set to 1, the memory becomes read-only. User memory is not stored in EEPROM until an event becomes inactive. 2-Wire Serial Data Bus The DS1682 supports a bidirectional, 2-wire bus and data-transmission protocol. A device that sends data onto the bus is defined as a transmitter and a device receiving data, a receiver.
PAGE 12
DS1682 Total-Elapsed-Time Recorder with Alarm Depending upon the state of the R/W bit, two types of data transfer are possible: Data transfer from a master transmitter to a slave receiver. The first byte transmitted by the master is the slave address. Next follows a number of data bytes. The slave returns an acknowledge bit after each received byte. Data transfer from a slave transmitter to a master receiver. The master transmits the first byte (the slave address).
PAGE 13
DS1682 Total-Elapsed-Time Recorder with Alarm Chip Information Ordering Information PART PIN-PACKAGE TOP MARK DS1682S+ 8 SO DS1682 DS1682S+T&R 8 SO DS1682 Note: All devices are specified over the -40°C to +85°C operating range. +Denotes a lead(Pb)-free/RoHS-compliant package. T&R = Tape and reel. www.maximintegrated.com PROCESS: CMOS Package Information For the latest package outline information and land patterns (footprints), go to www.maximintegrated.com/packages.
PAGE 14
DS1682 Total-Elapsed-Time Recorder with Alarm Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 1 11/13 Added the lead and soldering temperature information to the Absolute Maximum Ratings section; updated the Ordering Information and Package Information tables 2, 14 For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642, or visit Maxim Integrated’s website at www.maximintegrated.com.