DS1558 Maxim, DS1558 Datasheet
DS1558
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DS1558 Summary of contents
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... TQFP ( 1mm) 5.0 48 TQFP ( 1mm) 5.0 48 TQFP ( 1mm DS1558 36 A15 35 V BAT1 WE 34 IRQ/ A13 DS1558 A11 A10 CE 26 OER 25 TQFP TOP MARK* DS1558D DS1558D DS1558D DS1558D DS1558B DS1558B DS1558B DS1558B www.maxim-ic.com/errata. REV: 071305 ...
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... It is open drain and requires an external pullup resistor Active-Low Write Enable. Used to write data to the RTC registers. FUNCTION r Ad ess Decode DS1558 uses the address read o write cycle should r be dire inputs to determine cted to the attached SRAM or to the ...
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... X1 designed for operation with a crystal having a specified load capacitance (C more information about crystal selection and crystal layout considerations, refer to Application Note 58: Crystal Considerations with Dallas Real-Time Clocks. The DS1558 47 X2 can also be driven by an external 32.768kHz oscillator. In this configuration, the X1 pin is connected to the external oscillator signal and the X2 pin is floated ...
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... NV SRAM controller. User access to all registers within the DS1558 is accomplished with a byte-wide interface as shown in Figure 1. The RTC registers contain century, year, month, date, day, hours, minutes, and seconds data in 24-hour BCD ...
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... DATA READ MODE The DS1558 is in the read mode whenever ripple-throu gh access to any valid address location. Valid data is available at the DQ pins within t the last address input is stable, provided that times are not m et, valid data is available at the latter of chip-enable access (t ...
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... The DS1558 has an internal circuit to prevent battery chargin are required, and none should be used. The DS1558 has two battery pins that operate independently; the DS1558 selects the higher of the two inputs. If only one battery is used, the battery should be attached and V should be grounded ...
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... CLOCK OPERATIONS Table 2 and the following paragraphs describe the operation of the RTC, alarm, and watchdog functions. Table 2. DS1558 REGISTER MAP ADDR ESS 7FFFF h 10 YEAR 7FFF 7FFFD 7FFF 7FFF 7FFFAh X 10 MINUTES 7FFF9h 10 SECONDS OSC ...
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... The alarm can be programmed to activate on a specific day of the month or repeat every day, hour, minute, or second. It can also be programmed to go off while the DS1558 is in the battery-backed state of operation to serve as a system wake-up. Alarm mask bits AM1–AM4 control the alarm mode. Table 3 shows the possible settings ...
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Table 3. ALARM MASK BITS AM4 AM3 AM2 hen regis T ter values m a larm c ond ition ac ...
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Figure 4. BACKUP MODE ALARM WAVEFORMS USING THE WATCHDOG TIMER The watchdog timer can be used to detect an out-of-control processor. T timer by setting the desired am five watchdog register bits BMB4–BMB0 RB1–RB0 select the resolution, where 00 = ...
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... +5V 10 Voltage og CC (All Inputs) = +3.3V 10 Battery Voltage TINGS al o pera tion of the device at these or any other conditions beyond sure to absolute maximum rating conditions for exten A SYMBOL MIN 2 2.0 -0 -0.3 V 2.5 BAT those indicated in the operation ...
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DC ELECTRICAL CHARACTERISTICS (V = +3.3V ±10% or +5V ±10 -40°C to +85°C.) CC PARAMETER Active Suppl y Current, +5V Active Suppl y Current, +3.3V TTL Standby, + TTL Standby, +3.3V ( ...
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READ CYCLE, AC CHARACTERISTICS (V = +3.3V ±10% or +5V ±10 -40°C to +85°C.) (Figure 5) CC PARAMETER Read Cycle Time Address Access Time to DQ Low-Z CE Acce ss Time CE Data Off Time ...
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WRITE CYCLE, AC CHARACTERISTIC ( 3.3V ±10% or +5V ±10% CC PARAMETER Write Cycle Tim e Address Access Pulse Width WE Pulse Width CE Data Setup Time Data Hold Time Data Hold Time Address Hold ...
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Figure 6. WRITE CYCLE TIMING, WRITE-ENA Figure 7. WRITE CYCLE TIMING, CHIP-ENABLE CONTROLLED BLE CONTROLLED ...
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POWER-UP/DOWN CHARACTERISTICS = +5V 10 -40°C o +85°C.) (Figure ARAMETE Before Power-Down V Fall Tim PF(MAX) PF( V ...
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POWER-UP/DOWN CHARACTERISTICS +3.3V 10 -40°C to +85°C.) (Figure PARAMETER Before Power-Down V Fall Time PF(MAX) PF(MIN) V Rise Time ...
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