Maxim > Products > Real-Time Clocks (RTCs) > DS1338, DS1338C, DS1338U, ...

DS1338, DS1338C, DS1338U, DS1338Z

I²C RTC with 56-Byte NV RAM

Overview

Technical Documents

Ordering Info

Status

Part Number	Status
DS1338	Active: In Production.
DS1338C	Active: In Production. See Ordering Information for details.
DS1338U	Active: In Production. See Ordering Information for details.
DS1338Z	Active: In Production.

Description

The DS1338 serial real-time clock (RTC) is a low-power, full binary-coded decimal (BCD) clock/calendar plus 56 bytes of NV SRAM. Address and data are transferred serially through an I²C interface. The clock/calendar provides seconds, minutes, hours, day, date, month, and year information. The end of the month date is automatically adjusted for months with fewer than 31 days, including corrections for leap year. The clock operates in either the 24-hour or 12-hour format with AM/PM indicator. The DS1338 has a built-in power-sense circuit that detects power failures and automatically switches to the backup supply, maintaining time and date operation.

Data Sheet

Download	Rev 8	(PDF, 241.2kB)
E-Mail

Key Features

RTC Counts Seconds, Minutes, Hours, Date of the Month, Month, Day of the Week, and Year with Leap-Year Compensation Valid Up to 2100
Available in a Surface-Mount Package with an Integrated Crystal (DS1338C)
56-Byte Battery-Backed General-Purpose RAM with Unlimited Writes
I²C Serial Interface
Programmable Square-Wave Output Signal
Automatic Power-Fail Detect and Switch Circuitry
-40°C to +85°C Operating Temperature Range
Underwriters Laboratories (UL) Recognized

Applications/Uses

Consumer Electronics (Set-Top Box, Digital Recording, Network Appliance)
Handhelds (GPS, POS Terminal)
Medical (Glucometer, Medicine Dispenser)
Office Equipment (Fax/Printer, Copier)
Other (Utility Meter, Vending Machine, Thermostat, Modem)
Telecommunications (Router, Switcher, Server)

Key Specifications:

Timekeeping & Real-Time Clocks

Part Number

Date/ Time Format

Interface

V_SUPPLY
(V)

Time Keeping Current
(nA)

C_L
(pF)

Memory Type

Memory Size
(Bytes)

Time of Day Alarms

Integrated XTAL

Budgetary Price

hh = sec/100

typ

See Notes

DS1338

YY-MM-DD/ HH:MM:SS

I²C

1.8

3.3

800

12.5

NV SRAM

$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 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

Product Guides

Real-Time Clocks (PDF)

Reliability Reports

Reliability Report:	DS1338.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
DS1338C-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
DS1338C-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
DS1338C-3		N/A	No Longer Available	DS1338C-3#	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
DS1338C-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
DS1338C-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: No Materials Analysis
DS1338C-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
DS1338C-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
DS1338U-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
DS1338U-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
DS1338U-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
DS1338U-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
DS1338U-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
DS1338U-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
DS1338U-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
DS1338U-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
DS1338U-33+T&R/C01			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
DS1338U-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
DS1338UA-33+		N/A	No Longer Available	DS1338U+033	USOP; Land Pattern: Not Available	-40°C to +85°C	See data sheet
DS1338UA-33+T&R		N/A	No Longer Available	DS1338U+33T	USOP; Land Pattern: Not Available	-40°C to +85°C	See data sheet
DS1338Z-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
Part Number	Free Sample	Buy	Status	Recommended Replacement	Package: TYPE PINS FOOTPRINT DRAWING CODE/VAR *	Temp	RoHS/Lead-Free? Materials Analysis
DS1338Z-18+			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
DS1338Z-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
DS1338Z-3+			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
DS1338Z-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+4*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1338Z-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: No Materials Analysis
DS1338Z-33			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
DS1338Z-33+			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
DS1338Z-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+2*	-40°C to +85°C	RoHS/Lead-Free: Lead Free Materials Analysis
DS1338Z-33/T&R			Active		SOIC(N);8 pin;30.9 mm² Outline Drawing:21-0041 (PDF) Land Pattern: 90-0096 (PDF) Use pkgcode/variation: S8-2*	-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.: 19-6019 Rev 8; 2011-10-11
This page last modified: 2011-10-11