Product Summary

The DS1644-120 is a 32k × 8 nonvolatile static RAM with a full function real time clock, which are both accessible in a byte-wide format. The nonvolatile timekeeping RAM is functionally equivalent to any JEDEC standard 32k × 8 SRAM. The DS1644-120 can also be easily substituted for ROM, EPROM and EEPROM, providing read/write nonvolatility and the addition of the real time clock function. The real time clock information of the DS1644-120 resides in the eight uppermost RAM locations. The RTC registers contain year, month, date, day, hours, minutes, and seconds data in 24-hour BCD format.

Parametrics

DS1644-120 absolute maximum ratings: (1)Voltage Range on Any Pin Relative to Ground: -0.3V to +6.0V; (2)Storage Temperature Range: -40℃ to +85℃, Noncondensing; (3)Operating Temperature Range: 0℃ to +70℃, Noncondensing; (4)Lead Temperature (soldering, 10s): +260℃; (5)Soldering Temperature (reflow, PowerCap package): +260℃.

Features

DS1644-120 features: (1)Integrated NV SRAM, Real-Time Clock, Crystal, Power-Fail Control Circuit and Lithium Energy Source; (2)Clock Registers are Accessed Identically to the Static RAM. These Registers are Resident in the Eight Top RAM Locations.; (3)Totally Nonvolatile with Over 10 Years of Operation in the Absence of Power; (4)BCD-Coded Year, Month, Date, Day, Hours, Minutes, and Seconds with Leap Year Compensation Valid Up to 2100; (5)Power-Fail Write Protection Allows for ±10% VCC Power Supply Tolerance.

Diagrams

DS1644-120 block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)		 Quantity
DS1644-120
DS1644-120
Maxim Integrated Products
Real Time Clock
Data Sheet
Negotiable 
DS1644-120+
DS1644-120+
Maxim Integrated Products
Real Time Clock NV Timekeeping RAM
Data Sheet
0-1: $25.16
1-25: $16.90
25-50: $12.25
50-100: $12.10