19-5058 Rev 5/10 DS1643/DS1643P Nonvolatile Timekeeping RAMs www.maxim-ic.com FEATURES PIN CONFIGURATIONS Integrated NV SRAM, Real-Time Clock, V N.C. 1 28 CC Crystal, Power-Fail Control Circuit and TOP VIEW A12 27 WE 2 Lithium Energy Source DS1643 A7 CE2 3 26 Clock Registers are Accessed Identically to the A6 4 25 A8 A9 Static RAM. These Registers Reside in the A5 5 24 A4 6 23 A11 Eight Top RAM Locations. A3 7 22 OE Totally Nonvolatile with Over 10 Years of A2 8 21 A10 Operation in the Absence of Power A1 9 20 CE Access Times of 85ns and 100ns A0 10 19 DQ7 DQ0 DQ6 BCD-Coded Year, Month, Date, Day, Hours, 11 18 12 17 DQ1 DQ5 Minutes, and Seconds with Leap Year 13 16 DQ2 DQ4 Compensation Valid Up to 2100 14 15 GND DQ3 Power-Fail Write Protection Allows for 10% V Power Supply Tolerance Encapsulated DIP CC (700-mil Extended) Lithium Energy Source is Electrically Disconnected to Retain Freshness Until Power is Applied for the First Time 34 N.C. 1 DS1643 Only (DIP Module) N.C. 2 33 N.C. N.C. Standard JEDEC Byte-Wide 8K x 8 RAM 32 N.C. 3 DS1643P N.C. 31 N.C. 4 PFO Pinout 30 5 A12 V CC 6 29 A11 WE UL Recognized 7 28 A10 OE 27 A9 8 DS1643P Only (PowerCap Module Board) CE 26 A8 9 DQ7 Surface Mountable Package for Direct 25 10 A7 DQ6 24 A6 11 DQ5 Connection to PowerCap Containing 23 12 A5 DQ4 22 A4 13 DQ3 Battery and Crystal 14 21 A3 DQ2 20 A2 15 Replaceable Battery (PowerCap) DQ1 X1 GND V X2 BAT 19 A1 16 DQ0 Power-Fail Output 18 17 A0 GND Pin-for-Pin Compatible with Other Densities of PowerCap Module Board DS164XP Timekeeping RAM (Uses DS9034PCX PowerCap) ORDERING INFORMATION VOLTAGE RANGE PART TEMP RANGE PIN-PACKAGE TOP MARK (V) DS1643-85+ 5.0 0C to +70C 28 EDIP (0.740) DS1643+85 5.0 0C to +70C DS1643-100+ 28 EDIP (0.740) DS1643+100 5.0 0C to +70C DS1643P-85+ 34-PowerCap* DS1643P+85 DS1643P-100+ 5.0 0C to +70C 34-PowerCap* DS1643P+100 *DS9034I-PCX+ and DS9034-PCX+ required (must be ordered separately). +Denotes a lead(Pb)-free/RoHS-compliant package. The top mark will include a + symbol on lead-free devices. 1 of 17 DS1643/DS1643P PIN DESCRIPTION PIN NAME FUNCTION PDIP PowerCap 1, 2, 3, 1 N.C. No Connection 3134 2 30 A12 3 25 A7 4 24 A6 5 23 A5 6 22 A4 7 21 A3 8 20 A2 Address Inputs 9 19 A1 10 18 A0 21 28 A10 23 29 A11 24 27 A9 25 26 A8 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 CE 20 8 Active-Low Chip-Enable Input 22 7 OE Active-Low Output-Enable Input 26 CE2 Chip-Enable 2 Input (Active High) 27 6 WE Active-Low Write-Enable Input 28 5 V Power-Supply Input CC Active-Low Power-Fail Output. This open-drain pin requires a 4 PFO pullup resistor for proper operation. 14 17 GND Ground X1, X2, Crystal Connection, Battery Connection V BAT 2 of 17