DS1744/DS1744P Y2K-Compliant, Nonvolatile Timekeeping RAMs FEATURES PIN CONFIGURATIONS Integrated NV SRAM, Real-Time Clock, TOP VIEW Crystal, Power-Fail Control Circuit, and Lithium Energy Source A14 1 28 V CC DS1744 2 27 Clock Registers are Accessed Identically to A12 WE 3 26 A7 A13 the Static RAM. These Registers are Resident 4 25 A8 A6 in the Eight Top RAM Locations. A5 5 24 A9 Century Byte Register (i.e., Y2K Compliant) A4 6 23 A11 7 22 A3 OE Totally Nonvolatile with Over 10 Years of 8 21 A2 A10 Operation in the Absence of Power 9 20 A1 CE BCD-Coded Century, Year, Month, Date, A0 10 19 DQ7 Day, Hours, Minutes, and Seconds with DQ0 11 18 DQ6 12 17 DQ1 DQ5 Automatic Leap-Year Compensation Valid 13 16 DQ2 DQ4 Up to the Year 2100 GND 14 15 DQ3 Battery Voltage-Level Indicator Flag Power-Fail Write Protection Allows for 10% EDIP V Power-Supply Tolerance CC Lithium Energy Source is Electrically Disconnected to Retain Freshness Until 34 N.C. N.C. 1 33 N.C. N.C. 2 Power is Applied for the First Time DS1744P N.C. 3 32 A14 31 4 A13 DIP Module Only RST 30 V 5 A12 CC A11 Standard JEDEC Byte-Wide 32k x 8 Static 6 29 WE 28 A10 7 OE RAM Pinout 27 8 A9 CE 9 26 A8 DQ7 PowerCap Module Board Only 25 A7 10 DQ6 24 11 A6 DQ5 Surface-Mountable Package for Direct 23 12 A5 DQ4 22 13 A4 Connection to PowerCap Containing DQ3 21 14 A3 DQ2 15 20 A2 Battery and Crystal DQ1 19 16 A1 DQ0 GND V X2 Replaceable Battery (PowerCap) X1 BAT 18 17 A0 GND Power-On Reset Output PowerCap MODULE BOARD Pin-for-Pin Compatible with Other Densities (Uses DS9034PCX+ or DS9034I-PCX+ PowerCap) of DS174xP Timekeeping RAM Also Available in Industrial Temperature Range: -40C to +85C UL Recognized 19-5502 Rev 6/13 1 of 16 DS1744/DS1744P Y2K-Compliant, Nonvolatile Timekeeping RAMs PIN DESCRIPTION PIN NAME FUNCTION EDIP PowerCap 1 32 A14 2 30 A12 3 25 A7 4 24 A6 5 23 A5 6 22 A4 7 21 A3 8 20 A2 Address Input 9 19 A1 10 18 A0 21 28 A10 23 29 A11 24 27 A9 25 26 A8 26 31 A13 11 16 DQ0 12 15 DQ1 13 14 DQ2 15 13 DQ3 Data Input/Output 16 12 DQ4 17 11 DQ5 18 10 DQ6 19 9 DQ7 14 17 GND Ground 20 8 CE Active-Low Chip-Enable Input 22 7 OE Active-Low Output-Enable Input 27 6 WE Active-Low Write-Enable Input 28 5 V Power-Supply Input CC Active-Low Reset Output, Open Drain. Requires a pullup resistor for 4 RST proper operation. 1, 2, 3, 33, N.C. No Connection 34 X1, X2, Crystal Connections, V Battery Connection BAT V BAT 2 of 16