Product Summary

The DS1747 is a full-function, year-2000-compliant (Y2KC), real-time clock/calendar (RTC) and 512k x 8 nonvolatile static RAM. User access to all registers within the DS1747 is accomplished with a byte-wide interface. The RTC information and control bits reside in the eight uppermost RAM locations. The RTC registers contain century, year, month, date, day, hours, minutes, and seconds data in 24-hour binary-coded decimal (BCD) format. Corrections for the date of each month and leap year are made automatically. The DS1747 also contains its own power-fail circuitry that deselects the device when the VCC supply is in an out-of-tolerance condition. This feature prevents loss of data from unpredictable system operation brought on by low VCC as errant access and update cycles are avoided.

Parametrics

DS1747 absolute maximum ratings: (1)Voltage Range on Any Pin Relative to Ground: -0.3V to +6.0V; (2)Operating Temperature Range: 0 to +70℃; (3)Storage Temperature Range: -40 to +85℃; (4)Lead Temperature (soldering, 10s): +260℃; (5)Soldering Temperature (reflow, PowerCap): +260℃.

Features

DS1747 features: (1)Integrated NV SRAM, Real-Time Clock (RTC), 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)Century Byte Register (Y2K Compliant); (4)Totally Nonvolatile with Over 10 Years of Operation in the Absence of Power; (5)BCD-Coded Century, Year, Month, Date, Day, Hours, Minutes, and Seconds with Automatic Leap Year Compensation Valid Up to the Year 2100; (6)Battery Voltage-Level Indicator Flag; (7)Power-Fail Write Protection Allows for ±10% VCC Power-Supply Tolerance; (8)Lithium Energy Source is Electrically Disconnected to Retain Freshness Until Power is Applied for the First Time.

Diagrams

DS1747 block diagram

Image Part No Mfg Description Data Sheet Download Pricing
(USD)
Quantity
DS1747-70
DS1747-70

Maxim Integrated Products

Real Time Clock Timekeeping NV RAM

Data Sheet

Negotiable 
DS1747-70+
DS1747-70+

Maxim Integrated Products

Real Time Clock Timekeeping NV RAM

Data Sheet

0-1: $36.30
1-25: $24.37
25-50: $17.66
50-100: $17.45
DS1747-70IND
DS1747-70IND

Maxim Integrated Products

Real Time Clock Timekeeping NV RAM

Data Sheet

Negotiable 
DS1747P-70
DS1747P-70

Maxim Integrated Products

Real Time Clock

Data Sheet

Negotiable 
DS1747P-70+
DS1747P-70+

Maxim Integrated Products

Real Time Clock Timekeeping NV RAM

Data Sheet

0-14: $35.12
14-25: $23.58
25-50: $17.09
50-100: $16.89
DS1747W-120
DS1747W-120

Maxim Integrated Products

Real Time Clock

Data Sheet

Negotiable 
DS1747W-120+
DS1747W-120+

Maxim Integrated Products

Real Time Clock Timekeeping NV RAM

Data Sheet

0-1: $36.30
1-25: $24.37
25-50: $17.66
50-100: $17.45
DS1747W-120IND
DS1747W-120IND

Maxim Integrated Products

Real Time Clock Timekeeping NV RAM

Data Sheet

Negotiable