19-6078 Rev 11/11 DS1248/DS1248P 1024K NV SRAM with Phantom Clock FEATURES PIN CONFIGURATIONS Real-Time Clock (RTC) Keeps Track of Hundredths of Seconds, Minutes, Hours, TOP VIEW Days, Date of the Month, Months, and Years RST V 1 32 CC 128K x 8 NV SRAM Directly Replaces A16 31 A15 2 Volatile Static RAM or EEPROM N.C. A14 DS1248 3 30 A12 4 29 WE Embedded Lithium Energy Cell Maintains A13 A7 5 28 Calendar Operation and Retains RAM Data A8 A6 6 27 A9 A5 7 26 Watch Function is Transparent to RAM A11 A4 8 25 Operation A3 OE 9 24 A10 A2 10 23 Automatic Leap Year Compensation Valid CE A1 11 22 Up to 2100 12 21 DQ7 A0 13 20 DQ6 DQ0 Full 10% Operating Range 14 19 DQ5 DQ1 Over 10 Years of Data Retention in the DQ2 15 18 DQ4 17 DQ3 GND 16 Absence of Power Lithium Energy Source is Electrically Encapsulated DIP Disconnected to Retain Freshness Until (740-mil Flush) Power is Applied for the First Time DIP Module Only Standard 32-Pin JEDEC Pinout N.C. 1 34 RST 2 33 N.C. A15 DS1248P 32 A14 Underwriters Laboratories (UL) Recognized 3 A16 31 A13 4 N.C. (www.maxim-ic.com/qa/info/ul/) 30 5 A12 V CC 6 29 A11 WE 7 28 A10 OE PowerCap Module Board Only 27 A9 8 CE 26 A8 9 DQ7 Surface Mountable Package for Direct 25 10 A7 DQ6 24 11 A6 DQ5 Connection to PowerCap Containing 23 12 A5 DQ4 22 A4 13 DQ3 Battery and Crystal 21 14 A3 DQ2 20 A2 15 Replaceable Battery (PowerCap) DQ1 19 A1 16 DQ0 X1 GND V BAT X2 18 Pin-for-Pin Compatible with DS1244P and 17 A0 GND DS1251P PowerCap Module Board (Uses DS9034PCX+ PowerCap) 1 of 19 DS1248/DS1248P 1024K NV SRAM with Phantom Clock ORDERING INFORMATION PART TEMP RANGE V RANGE PIN-PACKAGE CC DS1248Y-70+ 0C to +70C 5V 10% 32 EDIP DS1248Y-70IND+ -40C to +85C 5V 10% 32 EDIP DS1248YP-70+ 0C to +70C 5V 10% 34 PowerCap* DS1248W-120+ 0C to +70C 3.3V 10% 32 EDIP DS1248W-120IND+ -40C to +85C 3.3V 10% 32 EDIP DS1248WP-120+ 0C to +70C 3.3V 10% 34 PowerCap* DS1248WP-120IND+ -40C to +85C 3.3V 10% 34 PowerCap* + Denotes a lead(Pb)-free/RoHS-compliant package. * DS9034PCX+ or DS9034I-PCX+ (PowerCap) required. Must be ordered separately. DETAILED DESCRIPTION The DS1248 1024K NV SRAM with phantom clock is a fully static, nonvolatile RAM (organized as 128K words by 8 bits) with a built-in real-time clock. The DS1248 has a self-contained lithium energy source and control circuitry, which constantly monitors V for an out-of-tolerance condition. When such CC a condition occurs, the lithium energy source is automatically switched on and writes protection is unconditionally enabled to prevent garbled data in both the memory and real-time clock. PACKAGES The DS1248 is available in two packages: 32-pin DIP and 34-pin PowerCap module. The 32-pin DIP style module integrates the crystal, lithium energy source, and silicon in one package. The 34-pin PowerCap module board is designed with contacts for connection to a separate PowerCap (DS9034PCX) that contains the crystal and battery. This design allows the PowerCap to be mounted on top of the DS1248P after completion of the surface mount process. Mounting the PowerCap after the surface mount process prevents damage to the crystal and battery because of the high temperatures required for solder reflow. The PowerCap is keyed to prevent reverse insertion. The PowerCap module board and PowerCap are ordered separately and shipped in separate containers. 2 of 19