Maxim > Products > Real-Time Clocks (RTCs) > DS1672

DS1672

I²C 32-Bit Binary Counter RTC

Low-Voltage, Serial Timekeeping Chip Combines an Ultra-Low-Voltage Clock with Sophisticated Power-Monitoring Circuitry, Power-Fail Switches, and a Switch to Optional Trickle-Charging, Replacing Several Discrete Components with One Chip

Overview

Technical Documents

Ordering Info

Status

Part Number	Status
DS1672	Active: In Production. See Ordering Information for details.

Description

The DS1672 low-voltage serial timekeeping chip incorporates a 32-bit counter and power-monitoring functions. The 32-bit counter is designed to count seconds and can be used to derive time-of-day, week, month, and year by using a software algorithm. A precision, temperature-compensated reference and comparator circuit monitors the status of V_CC. When an out-of-tolerance condition occurs, an internal power-fail signal is generated that forces the reset to the active state. When V_CC returns to an in-tolerance condition, the reset signal is kept in the active state for 250ms to allow the power supply and processor to stabilize.

Data Sheet

Download	Rev 5	(PDF, 191.6kB)
E-Mail

Key Features

32-Bit Counter
I²C Serial Interface
Automatic Power-Fail Detect and Switch Circuitry
Power-Fail Reset Output
Low-Voltage Oscillator Operation (1.3V min)
Trickle-Charge Capability
Underwriters Laboratories (UL) Recognized

Key Specifications:

Timekeeping & Real-Time Clocks

Part Number

Functions

Date/ Time Format

Interface

V_SUPPLY
(V)

Time Keeping Current
(nA)

C_L
(pF)

Memory Type

Time of Day Alarms

Integrated XTAL

Budgetary Price

hh = sec/100

typ

See Notes

DS1672

Elapsed Time Counter

Binary

I²C

3.3

425

None

$1.18 @1k

See All Timekeeping & Real-Time Clocks (86)

Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.

Diagram

Typical Operating Circuit

Application Notes

Application Note 58		Crystal Considerations with Maxim Real-Time Clocks (RTCs)
Application Note 82		Using the Dallas Tricklecharge Timekeeper
Application Note 504		Design Considerations for Maxim Real-Time Clocks
Application Note 505		Lithium Coin-Cell Batteries: Predicting an Application Lifetime
Application Note 511		Using the DS1672 Low-Voltage Serial Timekeeping IC
Application Note 517		DS1371/DS1372/DS1374 32-Bit Binary Counter Time Conversion
Application Note 701		Using the DS32kHz with Dallas Real-Time Clocks
Application Note 3816		Selecting a Backup Source for Real-Time Clocks
Application Note 4247		Oscillator Design Considerations for Low-Current Applications

Product Guides

Real-Time Clocks (PDF)

Reliability Reports

Reliability Report:	DS1672.pdf
Underwriters Laboratories (UL) Recognized

Software/Models

DS1672 IBIS Model

Ordering Information

Filters:

Part Number:

Package:

Temperature:

Tape and Reel

Sample

Part Number	Notes	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1672-2			N/A	No Longer Available	DS1672-2+	PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672-2+				Active		PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672-3			N/A	No Longer Available	DS1672-3+	PDIP(N);8 pin;79.7 mm² Land Pattern: Not Available Use pkgcode/variation: P8-9*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672-3+				Active		PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672-33			N/A	No Longer Available	DS1672-33+	PDIP(N);8 pin;79.7 mm² Land Pattern: Not Available Use pkgcode/variation: P8-9*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672-33+				Active		PDIP(N);8 pin;79.7 mm² Outline Drawing:21-0043 (PDF) Land Pattern: Not Applicable Use pkgcode/variation: P8+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672S-2+				Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672S-3	3V			Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672S-3+				Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672S-3+T&R				Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
Part Number	Notes	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1672S-33	3.3V			Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672S-33+				Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672S-33+T&R				Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+5*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672S-33/T&R				Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-4*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672U-2+				Active		µMAX;8 pin;16.2 mm² Outline Drawing:21-0036 (PDF) Land Pattern: 90-0092 (PDF) Use pkgcode/variation: U8+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672U-3	3V			Active	DS1672U-3+	µMAX;8 pin;16.2 mm² Outline Drawing:21-0036 (PDF) Land Pattern: 90-0092 (PDF) Use pkgcode/variation: U8-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672U-3+				Active		µMAX;8 pin;16.2 mm² Outline Drawing:21-0036 (PDF) Land Pattern: 90-0092 (PDF) Use pkgcode/variation: U8+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672U-33	3.3V			Active		µMAX;8 pin;16.2 mm² Outline Drawing:21-0036 (PDF) Land Pattern: 90-0092 (PDF) Use pkgcode/variation: U8-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1672U-33+				Active		µMAX;8 pin;16.2 mm² Outline Drawing:21-0036 (PDF) Land Pattern: 90-0092 (PDF) Use pkgcode/variation: U8+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1672U-33+T&R				Active		µMAX;8 pin;16.2 mm² Outline Drawing:21-0036 (PDF) Land Pattern: 90-0092 (PDF) Use pkgcode/variation: U8+1*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
Part Number	Notes	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1672U-33/T&R				Active		µMAX;8 pin;16.2 mm² Outline Drawing:21-0036 (PDF) Land Pattern: 90-0092 (PDF) Use pkgcode/variation: U8-1*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis

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; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product 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.

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Information Index

Overview		Technical Documents		Ordering Info		Related Products
Description Key Features Applications/Uses Key Specifications Diagram Notes and Comments		Data Sheet Application Notes Evaluation Kits Product Guides Reliability Reports Software/Models		Price and Availability Samples Buy Online Package Information Lead-Free Information		Similar Products by Function Similar Products by Application Evaluation Kits Products with Similar Part Numbers Products Used With This

Document Ref.: 19-6032 Rev 5; 2011-10-11
This page last modified: 2011-10-11