DS1643 Maxim, DS1643 Datasheet
DS1643
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DS1643 Summary of contents
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... Disconnected to Retain Freshness Until Power is Applied for the First Time DS1643 Only (DIP Module) Standard JEDEC Byte-Wide RAM Pinout UL Recognized DS1643P Only (PowerCap Module Board) Surface Mountable Package for Direct Connection to PowerCap Containing Battery and Crystal Replaceable Battery (PowerCap) Power-Fail Output ...
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... No Connection Address Inputs Data Input/Output Active-Low Chip-Enable Input Active-Low Output-Enable Input Chip-Enable 2 Input (Active High) Active-Low Write-Enable Input Power-Supply Input CC Active-Low Power-Fail Output. This open-drain pin requires a pullup resistor for proper operation. Ground Crystal Connection, Battery Connection BAT DS1643/DS1643P FUNCTION ...
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... DESCRIPTION The DS1643 nonvolatile static RAM with a full function Real Time Clock (RTC) that are both accessible in a byte-wide format. The nonvolatile timekeeping RAM is functionally equivalent to any JEDEC standard SRAM. The device can also be easily substituted in ROM, EPROM and EEPROM sockets providing read/write nonvolatility and the addition of the real time clock function ...
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... The 8-bit of the control register is the write bit. Setting the write bit like the read bit, halts updates to the DS1643 registers. The user can then load them with the correct day, date and time data in 24 hour BCD format. Resetting the write bit then transfers those values to the actual clock counters and allows normal operation to resume ...
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... CLOCK ACCURACY (DIP MODULE) The DS1643 is guaranteed to keep time accuracy to within 1 minute per month at 25C. CLOCK ACCURACY (POWERCAP MODULE) The DS1643P and DS9034PCX are each individually tested for accuracy. Once mounted together, the module is guaranteed to keep time accuracy to within 1.53 minutes per month (35ppm) at 25C. ...
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... The DS1643 has a lithium power source that is designed to provide energy for clock activity, and clock and RAM data retention when the V is sufficient to power the DS1643 continuously for the life of the equipment in which it is installed. For specification purposes, the life expectancy is 10 years at 25C with the internal clock oscillator running in the absence of V power ...
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... Write Protection Voltage SYMBOL MIN TYP V 4 -0.3 IL SYMBOL MIN TYP CC1 I 1 CC2 2 4.25 4. DS1643/DS1643P MAX UNITS NOTES 5 0 +0.8 V MAX UNITS NOTES A +1 0 ...
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... MAX CEL t 85 CEA t 95 CE2A t 30 CEZ t 5 OEL t 45 OEA t 30 OEZ DS1643/DS1643P 100ns ACCESS UNITS NOTES MIN MAX 100 ns 100 100 ns 105 ...
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... ACCESS MIN MAX WEW t 70 CEW t 75 CE2W WEZ DS1643/DS1643P 100ns ACCESS UNITS NOTES MIN MAX 100 ...
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... WRITE CYCLE TIMING DIAGRAM—WE CONTROLLED WRITE CYCLE TIMING DIAGRAM— , CE2 CONTROLLED DS1643/DS1643P ...
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... Capacitance on All Pins Capacitance on All Output Pins SYMBOL MIN TYP 300 REC SYMBOL MIN TYP DS1643/DS1643P MAX UNITS NOTES s s s years 5, 6 MAX UNITS NOTES ...
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... The CE2 control signal functions exactly the same as the active and inactive levels are opposite. 5) Data retention time is at 25C. 6) Each DS1643 has a built-in switch that disconnects the lithium source until V user. The expected t is defined for DIP modules as a cumulative time in the absence from the time power is first applied by the user ...
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... DS1643 28-PIN PACKAGE PKG 28-PIN DIM MIN A IN. 1.470 MM 37.34 B IN. 0.675 MM 17.75 C IN. 0.315 MM 8.51 D IN. 0.075 MM 1.91 E IN. 0.015 MM 0.38 F IN. 0.140 MM 3.56 G IN. 0.090 MM 2.29 H IN. 0.590 MM 14.99 J IN. 0.010 MM 0.25 K IN. 0.015 MM 0. DS1643/DS1643P MAX 1.490 37.85 0.740 18.80 0.335 9.02 0.105 2.67 0.030 0.76 0.180 4.57 0.110 2.79 0.630 16.00 0.018 0.45 0.025 ...
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... SECONDS. TO SOLDER, APPLY FLUX TO THE PAD, HEAT THE LEAD FRAME PAD AND APPLY SOLDER. TO REMOVE THE PART, APPLY FLUX, HEAT THE LEAD FRAME PAD UNTIL THE SOLDER REFLOWS AND USE A SOLDER WICK TO REMOVE SOLDER DS1643/DS1643P MAX 0.930 0.990 - 0.080 0.058 ...
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... DS1643P WITH DS9034PCX ATTACHED PKG INCHES DIM MIN NOM A 0.920 0.925 B 0.955 0.960 C 0.240 0.245 D 0.052 0.055 E 0.048 0.050 F 0.015 0.020 G 0.020 0.025 DS1643/DS1643P MAX 0.930 0.965 0.250 0.058 0.052 0.025 0.030 ...
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... RECOMMENDED POWERCAP MODULE LAND PATTERN PKG INCHES DIM MIN NOM A - 1.050 B - 0.826 C - 0.050 D - 0.030 E - 0.112 DS1643/DS1643P MAX - - - - - ...
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... © 2010 Maxim Integrated Products DESCRIPTION Maxim is a registered trademark of Maxim Integrated Products, Inc. DS1643/DS1643P PAGES CHANGED ...