Maxim > Products > Real-Time Clocks (RTCs) > DS1340, DS1340C

DS1340, DS1340C

I²C RTC with Trickle Charger

I²C Real-Time Clock with Trickle Charger Offers Software Clock Calibration

Overview

Technical Documents

Ordering Info

Status

Part Number	Status
DS1340	Active: In Production. See Ordering Information for details.
DS1340C	Active: In Production. See Ordering Information for details.

Description

The DS1340 is a real-time clock (RTC)/calendar that is pin compatible and functionally equivalent to the ST M41T00, including the software clock calibration. The device additionally provides trickle-charge capability on the V_BACKUP pin, a lower timekeeping voltage, and an oscillator STOP flag. Block access of the register map is identical to the ST device. Two additional registers, which are accessed individually, are required for the trickle charger and flag. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. A built-in power-sense circuit detects power failures and automatically switches to the backup supply. The device is programmed serially through an I²C bidirectional bus.

Data Sheet

Download	Rev 7	(PDF, 292kB)
E-Mail

Key Features

Enhanced Second Source for the ST M41T00
Available in a Surface-Mount Package with an Integrated Crystal (DS1340C)
Fast (400kHz) I²C Interface
Software Clock Calibration
RTC Counts Seconds, Minutes, Hours, Day, Date, Month, and Year
Automatic Power-Fail Detect and Switch Circuitry
Trickle-Charge Capability
Low Timekeeping Voltage Down to 1.3V
Three Operating Voltage Ranges (1.8V, 3V, and 3.3V)
Oscillator Stop Flag
Available in 8-Pin µSOP or SO Packages
Underwriters Laboratories (UL) Recognized

Applications/Uses

Medical Equipment
Point-of-Sale Equipment
Portable Instrumentation
Telecommunications

Key Specifications:

Timekeeping & Real-Time Clocks

Part Number

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

DS1340

YY-MM-DD/ HH:MM:SS

I²C

1.8

3.3

800

12.5

None

$1.12 @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 95		Interfacing the DS1307 with an 8051-Compatible Microcontroller
Application Note 504		Design Considerations for Maxim Real-Time Clocks
Application Note 505		Lithium Coin-Cell Batteries: Predicting an Application Lifetime
Application Note 701		Using the DS32kHz with Dallas Real-Time Clocks
Application Note 3572		FAQ About the Integrated-Crystal Package Option
Application Note 3816		Selecting a Backup Source for Real-Time Clocks
Application Note 3921		Using a DS1307 with a PIC Microcontroller
Application Note 4247		Oscillator Design Considerations for Low-Current Applications
Application Note 4427		Demonstrating Green Technology with Apples, Oranges, Lemons, and Limes

Product Guides

Real-Time Clocks (PDF)

Reliability Reports

Reliability Report:	DS1340.pdf
Request Reliability Report for:
Underwriters Laboratories (UL) Recognized

Software/Models

none

Ordering Information

Filters:

Part Number:

Package:

Temperature:

Tape and Reel

Sample

Part Number	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1340C-18			Active		SOIC(W);16 pin;110.6 mm² Outline Drawing:21-0042 (PDF) Land Pattern: 90-0107 (PDF) Use pkgcode/variation: W16-H2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1340C-18#			Active		SOIC(W);16 pin;110.6 mm² Outline Drawing:21-0042 (PDF) Land Pattern: 90-0107 (PDF) Use pkgcode/variation: W16#H2*	-40°C to +85°C	RoHS/Lead-Free: RoHS Qualified Materials Analysis
DS1340C-3			Active		SOIC(W);16 pin;110.6 mm² Outline Drawing:21-0042 (PDF) Land Pattern: 90-0107 (PDF) Use pkgcode/variation: W16-H2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1340C-3#			Active		SOIC(W);16 pin;110.6 mm² Outline Drawing:21-0042 (PDF) Land Pattern: 90-0107 (PDF) Use pkgcode/variation: W16#H2*	-40°C to +85°C	RoHS/Lead-Free: RoHS Qualified Materials Analysis
DS1340C-33		N/A	No Longer Available	DS1340C-33#	SOIC(W);16 pin;110.6 mm² Outline Drawing:21-0042 (PDF) Land Pattern: 90-0107 (PDF) Use pkgcode/variation: W16-H2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1340C-33#			Active		SOIC(W);16 pin;110.6 mm² Outline Drawing:21-0042 (PDF) Land Pattern: 90-0107 (PDF) Use pkgcode/variation: W16#H2*	-40°C to +85°C	RoHS/Lead-Free: RoHS Qualified Materials Analysis
DS1340C-33#T&R			Active		SOIC(W);16 pin;110.6 mm² Outline Drawing:21-0042 (PDF) Land Pattern: 90-0107 (PDF) Use pkgcode/variation: W16#H2*	-40°C to +85°C	RoHS/Lead-Free: RoHS Qualified Materials Analysis
DS1340U-18			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
DS1340U-18+			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
DS1340U-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: No Materials Analysis
Part Number	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1340U-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
DS1340U-3+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
DS1340U-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: No Materials Analysis
DS1340U-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
DS1340U-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
DS1340U-33/T&R		N/A	No Longer Available	DS1340U-33+T&R	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
DS1340Z-18			Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1340Z-18+			Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1340Z-3			Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1340Z-3+			Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
Part Number	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1340Z-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+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1340Z-33		N/A	No Longer Available	DS1340Z-33+	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-2*	-40°C to +85°C	RoHS/Lead-Free: No Materials Analysis
DS1340Z-33+			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: Lead Free Materials Analysis
DS1340Z-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: Lead Free Materials Analysis
DS1340Z-33/T&R		N/A	No Longer Available	DS1340Z-33+T&R	SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-2*	-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.: 19-5578 Rev 7; 2011-09-09
This page last modified: 2011-09-09