DS1387

Voltage on any Pin Relative to Ground                            0.3V to +7.0V
Operating Temperature                                                       0°C to 70°C
Storage Temperature                                      DS1387: 40°C to +70°C
                                                                     DS1385: 55°C to +125°C
Soldering Temperature                                         260°C for 10 seconds

* This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability.

The DS1385/DS1387 RAMified Real Time Clocks (RTCs) are upwardcompatible successors to the industry standard DS1285/DS1287 RTC's for PC applications. In addition to the basic DS1285/DS1287 RTC functions, 4K bytes of onchip nonvolatile RAM have been added.

The RTC functions of DS1385/DS1387 include a timeofday clock, a onehundred year calendar, timeofday interrupt, periodic interrupts, and an endofclock update cycle interrupt. In addition, 50bytes of user NV RAM are provided within this basic RTC function which can be used to store configuration data. The clock and user RAM are maintained in the absence of system V_CC by a lithium battery.

The 4K x 8 additional NV RAM DS1385/DS1387 is provided to store a much larger amount of system configuration data than is possible within the original 50byte area. This RAM is accessed via control signals separate from the RTC, and is also maintained as nonvolatile storage from the lithium battery.