ds1385s Maxim Integrated Products, Inc., ds1385s Datasheet
ds1385s
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ds1385s Summary of contents
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... Three interrupts are separately software–maskable and testable: – Time–of–day alarm once/second to once/day – Periodic rates from 122 s to 500 ms – End–of–clock update cycle Available as chip (DS1385 or DS1385S) or stand alone module with embedded lithium battery and crystal (DS1387) ORDERING INFORMATION DS1385 RTC Chip ...
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DS1385/DS1387 PIN DESCRIPTION OER – RAM Output Enable X1 – Crystal Input X2 – Crystal Output AD0-AD7 – Mux’ed Address/Data Bus CS – RTC Chip Select Input ALE – RTC Address Strobe WR – RTC Write Data Strobe RD – ...
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DS1385/DS1387 BLOCK DIAGRAM Figure OSC CS POWER V CC SWITCH AND WRITE POK PROTECT V BAT + +3V – BUFFER ENABLE ALE CLOCK/ BUS CALENDAR INTERFACE UPDATE AD0-AD7 AS1 BCD/BINARY ...
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DS1385/DS1387 WR (RTC Write Input) –The WR signal is an active low signal. The WR signal defines the time period during which data is written to the addressed clock register. CS (RTC Chip Select Input) – The Chip Select signal ...
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ADDRESS MAP DS1385/DS1387 Figure 14–BYTES 50–BYTES USER RAM 000 SRAM 4096 FFF TIME, CALENDAR AND ALARM LOCATIONS The time and calendar information is obtained by read- ...
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DS1385/DS1387 TIME, CALENDAR AND ALARM DATA MODES Table 1 ADDRESS ADDRESS FUNCTION FUNCTION LOCATION 0 Seconds 1 Seconds Alarm 2 Minutes 3 Minutes Alarm 4 Hours–12–hr Mode Hours–24–hr Mode 5 Hours Alarm–12–hr Hours Alarm–24–hr 6 Day of the Week Sunday ...
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The alternative flag bit usage method is with fully en- abled interrupts. When an interrupt flag bit is set and the corresponding interrupt enable bit is also set, the IRQ pin is asserted low. IRQ is asserted as long as ...
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DS1385/DS1387 PERIODIC INTERRUPT SELECTION The periodic interrupt will cause the IRQ pin active state from once every 500 ms to once every 122 s. This function is separate from the alarm inter- rupt which can be ...
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REGISTERS The DS1385/DS1387 has four control registers which are accessible at all times, even during the update cycle. REGISTER A MSB BIT 7 BIT 6 BIT 5 BIT 4 BIT 3 BIT 2 BIT 1 UIP DV2 DV1 DV0 RS3 ...
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DS1385/DS1387 AM it changes to 1:00:00 AM. These special updates do not occur when the DSE bit is a zero. This bit is not af- fected by internal functions. REGISTER C MSB BIT 7 BIT 6 BIT 5 BIT 4 ...
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ABSOLUTE MAXIMUM RATINGS* Voltage on any Pin Relative to Ground Operating Temperature Storage Temperature Soldering Temperature * This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the ...
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DS1385/DS1387 RTC AC TIMING CHARACTERISTICS PARAMETER SYMBOL Cycle Time t CYC Pulse Width, RD/WR Low PW EH Pulse Width, RD/WR High PW EL Input Rise and Fall Time Chip Select Setup Time Before t CS ...
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DS1385/DS1387 BUS TIMING FOR WRITE CYCLE TO RTC PW ASH ALE t ASD ASD ASL AD0–AD7 DS1385/DS1387 BUS TIMING FOR READ CYCLE TO RTC PW ASH ALE t ASD ...
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DS1385/DS1387 TIMING CHARACTERISTICS PARAMETER SYMBOL Address Setup Time t AS Address Hold Time t AH Data Setup Time t DS Data Hold Time t DH Output Enable Access Time t OEA Write Pulse Width t WP ...
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BUS TIMING FOR WRITE CYCLE SRAM t OER = V ASP IH AS0 AS1 WER AD0–AD7 LOW ADDRESS VALID UPPER ADDRESS VALID POWER–UP CONDITION CE 4.5V 4.25V 4. POWER FAIL ...
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DS1385/DS1387 POWER–DOWN CONDITION POWER FAIL POWER–UP POWER–DOWN TIMING PARAMETER SYMBOL CE High to Power Fail t PF Recovery at Power Up t REC V Slew Rate Power Down 4.0 < Slew Rate ...
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... All other inputs at CMOS levels. 7. Measured with a load as shown in Figure 4. 8. The real–time clock will keep time to an accuracy of 1 minute per month during data retention time for the period Applies to DS1385 and DS1385S only. OUTPUT LOAD Figure 4 D.U.T. 680 +5 VOLTS 1.1K ...
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DS1385/DS1387 DS1385 24–PIN DIP 012496 18/20 PKG 24–PIN DIM MIN MAX IN. 1.245 1.270 MM 31.62 32.26 B IN. 0.530 0.550 MM 13.46 13.97 C IN. 0.140 0.160 MM 3.56 4.06 ...
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... DS1385S 28–PIN SOIC 0–8 deg. typ PKG 28–PIN DIM MIN A IN. 0.706 MM 17.93 B IN. 0.338 MM 8.58 C IN. 0.086 MM 2.18 D IN. 0.020 MM 0.58 E IN. 0.002 MM 0.05 F IN. 0.090 MM 2.29 C 0.050 BSC G IN. 1. IN. 0.460 MM 11.68 J IN. 0.006 MM 0.15 K IN. 0.014 MM 0.36 F DS1385/DS1387 MAX 0.728 18.49 0.350 8 ...
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DS1385/DS1387 DS1387 24–PIN 740 MIL FLUSH ENCAPSULATED EQUAL SPACES AT .100 .010 TNA 012496 20/20 13 PKG 24–PIN DIM MIN A IN. 1.320 MM 33. IN. 0.720 MM ...