DS14285SSLASHTR datasheet(23/26 Pages) DALLAS

23 / 26 page

DS14285/DS14287

23 of 26

NOTES:

1) All voltages are referenced to ground.

2) All outputs are open.

3) The MOT pin has an internal pulldown of 20k

Ω.

4) The CEI pin has an internal pullup of 50k

Ω.

5) Applies to the AD0–AD7 pins, the IRQ pin, and the SQW pin when each is in the high impedance

state.

6) The IRQ pin is open drain. The interrupt and the internal clock continue to run regardless of the level

of VCC. However, it is important to insure that the pullup resistor used with the interrupt pin is never

pulled up to a value which is greater than VCC + 0.3V. As VCC falls below approximately 3.0 volts, a

power switching circuit turns the lithium energy source on to maintain the clock and timer data

functionality.

7) ICCO = 100mA, VCC > VBAT.

8) ICCO = 100µA, VCC < VBAT.

9) Measured with a load as shown in Figure 5.

10) Expected data retention is based on using an external SRAM with a data retention current of less than

µA at +25°C.

11) ZCE is an average input-to-output impedance as the input is swept from ground to VCCI and less than

4mA is forced through ZCE.

12) Real-Time Clock Modules such as the DS14287 can be successfully processed through conventional

wave-soldering techniques 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.

DS14285S/TR 数据表(PDF) 23 Page - Dallas Semiconductor