DP8572AV National Semiconductor, DP8572AV Datasheet
DP8572AV
Specifications of DP8572AV
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DP8572AV Summary of contents
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... This logic is used by the RTC to issue a power fail interrupt and lock out the p interface The time power fails may be logged into RAM automatically when V Block Diagram TRI-STATE is a registered trademark of National Semiconductor Corporation C 1995 National Semiconductor Corporation TL F 9980 V ...
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Absolute Maximum Ratings Specifications for the 883 version of this product are listed separately Supply Voltage ( Input Voltage ( Output Voltage ( ...
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AC Electrical Characteristics PFAIL Symbol READ TIMING t Address Valid Prior to Read Strobe AR t Read Strobe Width (Note Chip Select to Data ...
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... Absolute Maximum Ratings The 883 specifications are written to reflect the current (at the time of printing) Rel Electrical Test Specifica- tions (RETS) established by National Semiconductor for this product For a copy of the latest version of the RETS please contact your local National Semiconduc- tor sales office or distributor ...
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Military Version AC Electrical Characteristics and PFAIL Symbol READ TIMING t Address Valid Prior to Read Strobe AR t Read Strobe Width (Note ...
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Timing Waveforms Read Timing Diagram Write Timing Diagram 9980 – 9980 – 4 ...
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... GND This is the common ground power pin for both V and V CC Connection Diagrams Dual-In-Line P control Order Number DP8572AN or DP8572AMD 883 See NS Package Number D24C or N24C Plastic Chip Carrier The BB Top View Order Number DP8572AV See NS Package Number V28A Utiliz 9980 – 5 Top View TL F 9980 – 6 ...
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Functional Description The DP8572A contains a fast access real time clock inter- rupt control logic power fail detect logic and CMOS RAM All functions of the RTC are controlled by a set of seven registers A simplified block diagram that ...
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Functional Description (Continued) INITIAL POWER-ON of BOTH V and and V may be applied in any sequence In order for BB CC the power fail circuitry to function correctly whenever power is off the V pin ...
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Functional Description (Continued) The oscillator is programmed via the Real Time Mode Reg- ister to operate at various frequencies The crystal oscillator is designed to offer optimum performance at each frequen- cy Thus at 32 768 kHz the oscillator is ...
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Functional Description (Continued) Interrupts Fall Into Three Categories 1 The Alarm Compare Interrupt Issued when the value in the time compared RAM equals the counter 2 The Periodic Interrupts These are issued at every incre- ment of the specific clock ...
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Functional Description (Continued) 12 ...
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Functional Description (Continued) FIGURE 6 System-Battery Switchover (Upper Left) Power Fail If chip select is low when a power failure is detected a safety circuit will ensure that if a read or write is held active continuously for greater than ...
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Functional Description (Continued) the chip is unlocked but only after another 30 s min 63 s max debounce time The system designer must en- sure that his system is stable when power has returned The power fail circuitry contains active ...
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Functional Description (Continued) MAIN STATUS REGISTER The Main Status Register is always located at address 0 regardless of the register block or the page selected D0 This read only bit is a general interrupt status bit that is taken directly ...
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Functional Description (Continued) D5 The Delay Enable bit is used when a power fail occurs If this bit is set a 480 s delay is generated internally before the P interface is locked out This will enable the access the ...
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Functional Description (Continued) D7 This bit is used to program the signal appearing at the MFO output as follows D7 MFO Output Signal 0 Power Fail Interrupt 1 Buffered Crystal Oscillator INTERRUPT CONTROL REGISTER 0 D0 –D5 These bits are ...
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Control and Status Register Address Bit Map Main Status Register ADDRESS Page Register RAM Select Select Periodic Flag Register ...
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Application Hints Suggested Initialization Procedure for DP8572A in Battery Backed Applications that use the V Pin BB 1 Enter the test mode by writing bit D7 in the Period- ic Flag Register 2 Write zero to the ...
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Typical Performance Characteristics Operating Current vs Supply Voltage (Single Supply Mode F 32 768 kHz) e OSC Standby Current vs Power Supply Voltage (F 32 768 kHz) e OSC Operating Current vs Supply Voltage (Battery Backed Mode F 32 768 ...
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Physical Dimensions inches (millimeters) 24-Lead Hermetically Sealed Dual-In-Line Package (D) Order Number DP8572AMD 883 NS Package Number D24C Molded Dual-In-Line Package (N) Order Number DP8572AN NS Package Number N24C 21 ...
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... National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications Plastic Chip Carrier Package (V) Order Number DP8572AV NS Package Number V28A 2 A critical component is any component of a life ...