DS1556_10 Datasheet, PDF(17/18 Page) Maxim Integrated Products – 1M, Nonvolatile, Y2K-Compliant Timekeeping RAM

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DS1556_10 Datasheet, PDF (17/18 Pages) Maxim Integrated Products – 1M, Nonvolatile, Y2K-Compliant Timekeeping RAM

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DS1556 1M, Nonvolatile, Y2K-Compliant Timekeeping RAM

AC TEST CONDITIONS

Output Load: 50 pF + 1TTL Gate

Input Pulse Levels: 0.0 to 3.0V

Timing Measurement Reference Levels:

Input: 1.5V

Output: 1.5V

Input Pulse Rise and Fall Times: 5 ns

NOTES:

1. Voltage referenced to ground.

2. Typical values are at +25ï°C and nominal supplies.

3. Outputs are open.

4. Battery switchover occurs at the lower of either the battery voltage or VPF.

5. The IRQ/FT and RST outputs are open drain.

6. Data-retention time is at +25ï°C.

7. Each DS1556 has a built-in switch that disconnects the lithium source until VCC is first applied by the

user. The expected tDR is defined for DIP modules and PowerCap modules as a cumulative time in the

absence of VCC starting from the time power is first applied by the user.

8. RTC modules (DIP) can be successfully processed through conventional wave-soldering techniques

as long as temperature exposure to the lithium energy source contained within does not exceed

+85ï°C. Post-solder cleaning with water-washing techniques is acceptable, provided that ultrasonic

vibration is not used.

In addition, for the PowerCap:

a. Maxim recommends that PowerCap Module bases experience one pass through solder reflow

oriented with the label side up (âlive-bugâ).

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 reflow and use a solder wick to

remove solder.

9. tAH1, tDH1 are measured from WE going high.

10. tAH2, tDH2 are measured from CE going high.

11. tWC = 200ns.

PACKAGE INFORMATION

For the latest package outline information and land patterns, go to www.maxim-ic.com/packages. Note that a â+â, â#â, or â-â

in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing

pertains to the package regardless of RoHS status.

PACKAGE TYPE

PACKAGE CODE

OUTLINE NO. LAND PATTERN NO.

32 EDIP

MDF32+1

21-0245

34 PWRCP

PC2+6

21-0246

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