General Description

The DS1346/DS1347 SPI™-compatible real-time clocks (RTCs) contain a real-time clock/calendar and 31 x 8 bits of static random-access memory (SRAM). The real time clock/calendar provides seconds, minutes, hours, day, date, month, year, and century information. A time/date programmable polled ALARM is included in the devices. The end-of-the-month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24hr or 12hr format with an AM/PM indicator. The devices operate with a supply voltage of +2V to +5.5V, are available in the ultra-small 8-pin TDFN package, and work over the -40°C to +85°C industrial tempera ture range.

Features

♦ RTC Counts Seconds, Minutes, Hours, Day of Week, Date of Month, Month, Year, and Century

♦ Leap-Year Compensation

♦ +2V to +5.5V Wide Operating Voltage Range

♦ SPI (Mode 1 or 3) Interface: 4MHz at 5V, 1MHz at 2V

♦ 31 x 8-Bit SRAM for Scratchpad Data Storage

♦ Uses Standard 32.768kHz Watch Crystal

♦ Low Timekeeping Current (400nA at 2V)

♦ Single-Byte or Multiple-Byte (Burst Mode) Data Transfer for Read or Write of Clock Registers or SRAM

♦ Ultra-Small, 3mm x 3mm x 0.8mm, 8-Pin TDFN Package

♦ Programmable Time/Date Polled ALARM Function

♦ No External Crystal Bias Resistors or Capacitors Required