DS1248 Maxim, DS1248 Datasheet
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DS1248
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DS1248 Summary of contents
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... A11 A10 DQ7 13 20 DQ6 14 19 DQ5 DQ4 DQ3 16 (740-mil Flush) N. N.C. DS1248P 32 A14 31 A13 30 A12 A11 29 28 A10 GND BAT ...
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... 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 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 ...
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PIN DESCRIPTION PIN NAME EDIP PowerCap 1 1 RST 2 3 A16 3 32 A14 4 30 A12 ...
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... OE, rather than address access. RAM WRITE MODE The DS1248 is in the write mode whenever the WE and CE signals are in the active (low) state after address inputs are stable. The latter occurring falling edge will determine the start of the write cycle. The write cycle is terminated by the earlier rising edge of CEor WE. All address inputs must be kept valid throughout the write cycle ...
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PHANTOM CLOCK OPERATION Communication with the phantom clock is established by pattern recognition on a serial bit stream of 64 bits, which must be matched by executing 64 consecutive write cycles containing the proper data on DQ0. All accesses that ...
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Figure 1. Phantom Clock Register Definition NOTE: THE PATTERN RECOGNITION IN HEX IS C5, 3A, A3, 5C, C5, 3A, A3, 5C. THE ODDS OF THIS PATTERN BEING ACCIDENTALLY DUPLICATED AND CAUSING INADVERTENT ENTRY TO THE PHANTOM CLOCK IS LESS THAN ...
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Figure 2. Phantom Clock Register Definition AM/PM/12/24-MODE Bit 7 of the hours register is defined as the 12-hour or 24-hour mode-select bit. When high, the 12-hour mode is selected. In the 12-hour mode, bit 5 is the AM/PM bit with ...
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... The DS1248 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 DS1248 continuously for the life of the equipment in which it is installed. For specification purposes, the life expectancy is 10 years at +25°C with the internal clock oscillator running in the absence of V power ...
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... Soldering Temperature (reflow, PowerCap) ......................................................................................+260°C This is a stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of time can affect reliability. ...
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... Data Setup Time Data Hold Time from WE SYMBOL MIN CCS1 I CCS2 I CC01 V 2. SYMBOL MIN I/O DS1248Y-70 SYMBOL MIN ACC COE ODW ...
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PHANTOM CLOCK AC ELECTRICAL CHARACTERISTICS Over the Operating Range (5V) PARAMETER Read Cycle Time CE Access Time OE Access Time CE to Output Low Output Low Output High Output High-Z Read Recovery Write Cycle ...
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... CE to Output Low Output Low Output High Output High-Z Read Recovery Write Cycle Time Write Pulse Width Write Recovery Data Setup Time Data Hold Time CE Pulse Width RST Pulse Width DS1248W-120 SYMBOL MIN t 120 RC t ACC ...
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POWER-DOWN/POWER-UP TIMING Over the Operating Range (3.3V) PARAMETER before Power-Down IH V Slew from PF(MAX PF(MIN Slew from PF(MAX ...
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MEMORY WRITE CYCLE 1 (Notes 2, 6, and 7) MEMORY WRITE CYCLE 2 (Notes 2 and ...
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RESET FOR PHANTOM CLOCK READ CYCLE TO PHANTOM CLOCK WRITE CYCLE TO PHANTOM CLOCK ...
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POWER-DOWN/POWER-UP CONDITION (5V) POWER-DOWN/POWER-UP CONDITION (3.3V ...
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AC TEST CONDITIONS Output Load: 50pF + 1TTL Gate Input Pulse Levels Timing Measurement Reference Levels Input: 1.5V Output: 1.5V Input Pulse Rise and Fall Times: 5ns NOTES high for a read cycle. 2) ...
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... PACKAGE INFORMATION For the latest package outline information and land patterns (footprints www.maxim-ic.com/packages. Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a different suffix character, but the drawing pertains to the package regardless of RoHS status. ...
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... © 2011 Maxim Integrated Products DS1248/DS1248P 1024K NV SRAM with Phantom Clock DESCRIPTION Maxim is a registered trademark of Maxim Integrated Products, Inc ...