DS1486 Datasheet, PDF (13/17 Pages) Dallas Semiconductor – RAMified Watchdog Timekeeper

NOTES:
DS1486/DS1486P
1. WE is high for a read cycle.
2. OE = V_IH or V_IL. If OE = V_IH during write cycle, the output buffers remain in a high impedance state.
3. t_WP is specified as the logical AND of the CE and WE . t_WP is measured from the latter of CE or WE
going low to the earlier of CE or WE going high.
4. t_DS or t_DH are measured from the earlier of CE or WE going high.
5. t_DH is measured from WE going high. If CE is used to terminate the write cycle, then t_DH = 20 ns for
-120 parts and t_DH = -25 ns for -150 parts.
6. If the CE low transition occurs simultaneously with or later than the WE low transition in write cycle
1, the output buffers remain in a high impedance state during this period.
7. If the CE high transition occurs prior to or simultaneously with the WE high transition, the output
buffers remain in a high impedance state during this period.
8. If WE is low or the WE low transition occurs prior to or simultaneously with the CE low transition,
the output buffers remain in a high impedance state during this period.
9. Each DS1486 is marked with a four-digit date code AABB. AA designates the year of manufacture.
BB designates the week of manufacture. The expected t_DR is defined for DIP Modules as starting at
the date of manufacture.
10. All voltages are referenced to ground.
11. Applies to both interrupt pins when the alarms are set to pulse.
12. Interrupt output occurs within 100 ns on the alarm condition existing.
13. Both INTA and INTB (INTB) are open drain outputs.
14. Real-Time Clock Modules (DIP) can be successfully processed through conventional wave-soldering
tech-niques as long as temperature exposure to the lithium energy source contained within does not
exceed +85°C. Post-solder cleaning with water washing techniques is acceptable, provided that
ultrasonic vibration is not used.
In addition, for the PowerCap version:
a. Dallas Semiconductor recommends that PowerCap Module bases experience one pass through
solder reflow oriented with the label side up (“live - bug”).
b. Hand Soldering and touch-up: Do not touch or apply the soldering iron to leads for more than
3 seconds. To solder, apply flux to the pad, heat the lead frame pad and apply solder. To
remove the part, apply flux, heat the lead frame pad until the solder reflows and use a solder
wick to remove solder.
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