DS1557WP-120+ Maxim Integrated Products, DS1557WP-120+ Datasheet
DS1557WP-120+
Specifications of DS1557WP-120+
Related parts for DS1557WP-120+
DS1557WP-120+ Summary of contents
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Rev 9/10 www.maxim-ic.com FEATURES Integrated NV SRAM, Real-Time Clock (RTC), Crystal, Power-Fail Control Circuit, and Lithium Energy Source Clock Registers are Accessed Identically to the Static RAM; These Registers Reside in the 16 Top RAM Locations ...
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... ORDERING INFORMATION PART TEMP RANGE DS1557P-70+ 0°C to +70°C DS1557P-70IND+ -40°C to +85°C DS1557WP-120+ 0°C to +70°C DS1557WP-120IND+ -40°C to +85°C + Denotes a lead(Pb)-free/RoHS-compliant package. *DS9034PCX+ or DS9034I-PCX+ (PowerCap) required. Must be ordered separately. *An “IND” on the top mark denotes an industrial temperature grade device. ...
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Figure 1. Block Diagram Table 1. Operating Modes > < V < < V < ...
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DATA WRITE MODE The DS1557 is in the write mode whenever WE and CE are in their active state. The start of a write is referenced to the latter occurring transition CE. The addresses must be held ...
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CLOCK OPERATIONS Table 2 and the following paragraphs describe the operation of RTC, alarm, and watchdog functions. Table 2. Register Map ADDRESS 7FFFFh 10 Year 7FFFEh X X 7FFFDh X X 7FFFCh X FT 7FFFBh X ...
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CLOCK OSCILLATOR CONTROL The clock oscillator may be stopped at any time. To increase the shelf life of the backup lithium battery source, the oscillator can be turned off to minimize current drain from the battery. The OSC bit is ...
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USING THE CLOCK ALARM The alarm settings and control for the DS1557 reside within Registers 7FFF2h-7FFF5h. Register 7FFF6h contains two alarm enable bits: Alarm Enable (AE) and Alarm in Backup Enable (ABE). The AE and ABE bits must be set ...
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Figure 3. Clearing IRQ Waveforms The IRQ/FT pin can also be activated in the battery-backed mode. The IRQ/FT will go low if an alarm occurs and both ABE and AE are set. The ABE ...
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USING THE WATCHDOG TIMER The watchdog timer can be used to detect an out-of-control processor. The user programs the watchdog timer by setting the desired amount of timeout into the 8-bit Watchdog Register (Address 7FFF7h). The five Watchdog Register bits ...
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ABSOLUTE MAXIMUM RATINGS Voltage Range on Any Pin Relative to Ground………………………………………………………………-0.3V to +6.0V Storage Temperature Range…………...………………………………………………………….....……..-55°C to +125°C Lead Temperature (soldering, 10s).....................................................................................................…………+260°C Soldering Temperature (reflow)………………………………………………………………………………………. +260°C This is a stress rating only and functional operation of the device at these ...
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DC ELECTRICAL CHARACTERISTICS (V = 3.3V ±10 Over the Operating Range PARAMETER Active Supply Current TTL Standby Current ( CMOS Standby Current (CE V - 0.2V) CC Input Leakage Current (Any Input) ...
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AC CHARACTERISTICS—READ CYCLE (T = Over the Operating Range) A PARAMETER Read Cycle Time Address Access Time Low-Z CE Access Time CE Data Off Time Low-Z OE Access Time OE Data Off Time Output ...
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Figure 6. Write Cycle Timing, Write-Enable Controlled Figure 7. Write Cycle Timing, Chip-Enable Controlled DS1557 4Meg, Nonvolatile, Y2K-Compliant Timekeeping RAM ...
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POWER-UP/DOWN CHARACTERISTICS— 5.0V ±10 Over the Operating Range PARAMETER Before IH Power-Down V Fall Time PF(MAX) PF(MIN) V Fall Time ...
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POWER-UP/DOWN CHARACTERISTICS—3. 3.3V ±10 Over the Operating Range PARAMETER Before IH Power-Down V Fall Time PF(MAX) PF(MIN) V Rise Time ...
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AC TEST CONDITIONS Output Load 1TTL Gate Input Pulse Levels 3.0V Timing Measurement Reference Levels: Input: 1.5V Output: 1.5V Input Pulse Rise and Fall Times NOTES: 1) Voltage referenced to ground. 2) Typical ...
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... Maxim reserves the right to change the circuitry and specifications without notice at any time 2010 Maxim Integrated Products DS1557 4Meg, Nonvolatile, Y2K-Compliant Timekeeping RAM DESCRIPTION parameter in the DC Electrical Maxim and the Dallas logo are registered trademarks of Maxim Integrated Products. PAGES CHANGED 2, 10, 11, 16 ...