Dallas Semiconductor

DS1305 - 3-Wire/SPI Serial Interface Trickle Charge Real-Time Clock

Photograph

Features Real-time clock (RTC) counts seconds, minutes, hours, date of the month, month, day of the week, and year with leap-year compensation valid up to 2100 96-byte, battery-backed, nonvolatile (NV) RAM for data storage Two time-of-day alarms—programmable on combination of seconds, minutes, hours, and day of the week Serial interface supports Motorola Serial Peripheral Interface (SPI) serial data ports or standard 3-wire interface Dual-power supply pins for primary and backup power supplies Optional trickle charge output to backup supply Underwriters Laboratory (UL) recognized

Pin Description Pin Number Description 1 Vcc2 - Backup Power Supply 2 Vbat - +3V Battery Input 3 X1 - 32.768kHz Crystal 4 X2 - 32.768kHz Crystal 5 NC - Not Connected 6 INT0 - Interrupt 0 Output 7 INT1 - Interrupt 1 Output 8 GND - Ground 9 SEMODE - Serial Interface Mode 10 CE - Chip Enable 11 SCLK - Serial Clock 12 SDI - Serial Data In 13 SDO - Serial Data Out 14 Vccif - Interface Logic Power Supply Input 15 PF - Power Fail Output 16 Vcc1 - Primary Power Supply

Pin Layout Dimensional Drawing

Technical Data Data Sheet Dallas Semiconductor - Data Sheet for DS1305 Application Notes