DS1691

www.DataSheet4U.com DS1688/DS1691 DS1688/DS1691 3 Volt/5 Volt Serialized Real Time Clock with NV RAM Control FEATURES Incorporates industry standard DS1287 PC clock plus enhanced features: PIN ASSIGNMENT VBAUX X1 X2 RCLR AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7 PWR GND 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 CEI CEO VCCI VCCO SQW VBAT IRQ PSEL RD GND WR ALE CS KS VBAUX X1 X2 RCLR AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7 PWR GND 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 CEI CEO VCCI VCCO SQW VBAT IRQ PSEL RD GND WR ALE CS KS +3 or +5 volt operation 64–bit Silicon serial number 64–bit customer specific ROM or additional serial number available control circuitry supports system power on from date/time alarm or key closure battery backup and write protection to external SRAM 12.5 pF crystal Power Automatic Crystal select bit allows RTC to operate with 6 pF or 114 bytes user NVRAM Auxiliary battery input RAM clear input Century register 32 KHz output for power management 32–bit VCC powered elapsed time counter 32–bit VBAT powered elapsed time counter 16–bit power cycle counter Compatible with functions existing BIOS for original DS1287 DS1688 28–PIN DIP (600 MIL) VBAUX NC NC RCLR AD0 AD1 AD2 AD3 AD4 AD5 AD6 AD7 PWR GND 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 DS1688S 28–PIN SOIC (330 MIL) CEI CEO VCCI VCCO SQW NC IRQ PSEL RD NC WR ALE CS KS DS1691 28–PIN E...