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Data Sheet

FULL DATA SHEET (PDF, 392kB) Download   E-Mail

Description

The DS1284/DS1286 watchdog timekeepers are self-contained real-time clocks, alarms, watchdog timers, and interval timers in a 28-pin JEDEC DIP and encapsulated DIP package. The DS1286 contains an embedded lithium energy source and a quartz crystal, which eliminates the need for any external circuitry. The DS1284 requires an external quartz crystal and a VBAT source, which could be a lithium battery. Data contained within 64 8-bit registers can be read or written in the same manner as byte-wide static RAM. Data is maintained in the watchdog timekeeper by intelligent control circuitry that detects the status of VCC and write protects memory when VCC is out of tolerance. The lithium energy source can maintain data and real time for over 10 years in the absence of VCC. Watchdog timekeeper information includes hundredths of seconds, seconds, minutes, hours, day, date, month, and year. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including correction for leap year. The DS1284/DS1286 operate in either 24-hour or 12- hour format with an AM/PM indicator. The devices provide alarm windows and interval timing between 0.01 seconds and 99.99 seconds. The real-time alarm provides for preset times of up to one week.

Key Features

Keeps Track of Hundredths of Seconds, Seconds, Minutes, Hours, Days, Date of the Month, Months, and Years; Valid Leap Year Compensation Up to 2100 Watchdog Timer Restarts an Out-of-Control Processor Alarm Function Schedules Real-Time-Related Activities Embedded Lithium Energy Cell Maintains Time, Watchdog, User RAM, and Alarm Information Programmable Interrupts and Square-Wave Outputs Maintain JEDEC Footprint All Registers are Individually Addressable via the Address and Data Bus Accuracy is Better than ±1 Minute/Month at +25°C Greater than 10 Years of Timekeeping in the Absence of VCC 50 Bytes of User NV RAM UL Recognized -40°C to +85°C Industrial Temperature Range

Application Notes

Application Note 58: Crystal Considerations with Dallas Real-Time Clocks (RTCs) - DS1284 Application Note 66: Watchdog Timekeeper - DS1284, DS1286 Application Note 504: Design Considerations for Dallas Semiconductor Real-Time Clocks - DS1284, DS1286 Application Note 505: Lithium Coin-Cell Batteries: Predicting an Application Lifetime - DS1284 Application Note 701: Using the DS32kHz with Dallas Real-Time Clocks - DS1284

Evaluation Kits

none

Design Guides

REAL-TIME CLOCKS (PDF) SYSTEM TIMING & CONTROL (PDF)

Reliability Reports

Reliability Report: DS1284.pdf DS1286.pdf

Software/Models

none

Ordering Information
Notes: Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales. Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day. Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt. More: SeeFull Data Sheet or Part Naming Conventions. * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.
Devices: 1-15 of 15
DS1284	Free Sample	Buy	Package: TYPE PINS FOOTPRINT   DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1284			PDIP;28 pin; Dwg: 56-G5000-002 Use pkgcode/variation: P28-9*	0°C to +70°C	See data sheet
DS1284+			PDIP;28 pin; Dwg: 56-G5000-002 Use pkgcode/variation: P28+9*	0°C to +70°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1284N			PDIP;28 pin; Dwg: 21-0044B (PDF) Use pkgcode/variation: P28-6*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1284Q			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28-3*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
DS1284Q/T&R			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28-3*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
DS1284Q+			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28+11*	0°C to +70°C	See data sheet
DS1284QN			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28-3*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1284QN/T&R			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28-3*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1284QN+T&R			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28+11*	-40°C to +85°C	See data sheet
DS1284Q+T&R			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28+11*	-40°C to +85°C	See data sheet
DS1284QN+			PLCC;28 pin; Dwg: 21-0049D (PDF) Use pkgcode/variation: Q28+11*	-40°C to +85°C	See data sheet
DS1286	Free Sample	Buy	Package: TYPE PINS FOOTPRINT   DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1286+			MOD;28 pin; Dwg: 56-G0001-001 Use pkgcode/variation: MDP28+1*	0°C to +70°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1286			MOD;28 pin; Dwg: 56-G0001-001 Use pkgcode/variation: MDP28-1*	0°C to +70°C	RoHS/Lead-Free: No Materials Analysis
DS1286I			MOD;28 pin; Dwg: 56-G0001-001 Use pkgcode/variation: MDP28-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1286I+			MOD;28 pin; Dwg: 56-G0001-001 Use pkgcode/variation: MDP28+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis

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