DS17885

DS17885/DS17887 3V/5V Real-Time Clock www.maxim-ic.com FEATURES Incorporates industry standard DS1287 PC clock plus enhanced features: § Y2K compliant § +3V or +5V operation § SMI recovery stack § 64-bit silicon serial number § Power-control circuitry supports system power-on from date/time alarm or key closure § 32kHz output on power-up § Crystal select bit allows RTC to operate with 6pF or 12.5pF crystal § 114 bytes user NV RAM § Auxiliary battery input § 8kB additional NV RAM § RAM clear input § Century register § Date alarm register § Compatible with existing BIOS for original DS1287 functions § Available as chip (DS17885) or standalone module with embedded battery and crystal (DS17887) § Timekeeping algorithm includes leap-year compensation valid up to 2100 § Underwriters Laboratory (UL) recognized PIN ASSIGNMENT PWR X1 X2 AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7 GND 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 VCC SQW VBAUX RCLR VBAT IRQ KS RD GND WR ALE CS DS17885 24-Pin DIP DS17885S 24-Pin SO PWR NC NC AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7 GND 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 VCC SQW VBAUX RCLR NC IRQ KS RD NC WR ALE CS DS17887 24-Pin Encapsulated Package TYPICAL OPERATING CIRCUIT IRQ VBAT RCLR VBAUX SQW VCC VCC PWR X1 X2 NC ADO AD1 AD2 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 KS RD GND WR ALE CS GND GND AD7 AD6 NC AD5 AD4 AD3 DS17885E 28-Pin TSOP 1 of 38 050802 DS17885/DS17887 ORDERING I...