Product Summary

The DS1643-100 is an 8K×8 nonvolatile static RAM with a full function real time clock which are both accessible in a bytewide format. The nonvolatile time keeping RAM is pin and function equivalent to any JEDEC standard 8K×8 SRAM. The DS1643-100 can also be easily substituted in ROM, EPROM and EEPROM sockets providing read/ write nonvolatility and the addition of the real time clock function. The real time clock information resides in the eight uppermost RAM locations. The DS1643-100 RTC registers contain year, month, date, day, hours, minutes, and seconds data in 24 hour BCD format. Corrections for the day of the month and leap year are made automatically.

Parametrics

DS1643-100 absolute maximum ratings: (1)Voltage on Any Pin Relative to Ground: –0.3V to +7.0V; (2)Operating Temperature: 0 to 70℃; (3)Storage Temperature: –20 to +70℃; (4)Soldering Temperature: 260℃ for 10 seconds.

Features

DS1643-100 features: (1)Form, fit, and function compatible with the MK48T08 Timekeeping RAM; (2)Integrated NV SRAM, real time clock, crystal, power–fail control circuit and lithium energy source; (3)Standard JEDEC bytewide 8K×8 static RAM pinout; (4)Clock registers are accessed identical to the static RAM. These registers are resident in the eight top RAM locations; (5)Totally nonvolatile with over 10 years of operation in the absence of power; (6)Access times of 120 ns and 150 ns; (7)Quartz accuracy ±1 minute a month @ 25℃, factory calibrated; (8)BCD coded year, month, date, day, hours, minutes, and seconds with leap year compensation valid up to 2100; (9)Power–fail write protection allows for ±10% VCC power supply tolerance.

Diagrams

DS1643-100 block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)		 Quantity
DS1643-100
DS1643-100
Maxim Integrated Products
Real Time Clock NV Timekeeping RAM
Data Sheet
Negotiable 
DS1643-100+
DS1643-100+
Maxim Integrated Products
Real Time Clock NV Timekeeping RAM
Data Sheet
0-1: $16.89
1-25: $11.34
25-50: $8.22
50-100: $8.12