DS1388 I²C RTC/Supervisor with Trickle Charger and 512 Bytes EEPROM

Description

The DS1388 I²C real-time clock (RTC), supervisor, and EEPROM is a multifunction device that provides a clock/calendar, programmable watchdog timer, power-supply monitor with reset, and 512 bytes of EEPROM. The clock provides hundredths of seconds, seconds, minutes, and hours, and operates in 24-hour or 12-hour format with an AM/PM indicator. The calendar provides day, date, month, and year information. The date at the end of the month is automatically adjusted for months with fewer than 31 days, including corrections for leap year. A watchdog timer provides a reset for an unresponsive microprocessor. It is programmable in 10ms intervals from 0.01 to 99.99 seconds. A temperature-compensated voltage reference and comparator circuit monitors the status of V_CC. If a primary power failure is detected, the device automatically switches to the backup supply and drives the reset output to the active state. The backup supply maintains time and date operation in the absence of V_CC. When V_CC returns to nominal levels, the reset is held low for a period to allow the power supply and processor to stabilize. The device also has a pushbutton reset controller, which debounces a reset input signal. The device is accessed through an I²C serial interface.

Key Features

Applications/Uses

Fast (400kHz) I²C Interface
RTC Counts Hundredths of Seconds, Seconds, Minutes, Hours, Day, Date, Month, and Year with Leap Year Compensation Valid Up to 2100
Programmable Watchdog Timer
Automatic Power-Fail Detect and Switch Circuitry
Reset Output with Pushbutton Reset Input Capability
512 x 8 Bits of EEPROM
Integrated Trickle-Charge Capability for Backup Supply
Three Operating Voltages: 5.0V, 3.3V, and 3.0V
Low Timekeeping Voltage Down to 1.3V
-40°C to +85°C Temperature Range
Underwriters Laboratories (UL®) Recognized

	Network-Interface Cards
	Point-of-Sale Equipment
	Portable Instrumentation
	Wireless Equipment

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

Memory Size
(Bytes)

Time of Day Alarms

Price

hh = sec/100

typ

See Notes

DS1388

Watchdog Timekeeper

YY-MM-DD/ HH:MM:SS:hh

I²C

3.3

410

EEPROM

512

$1.66 @1k

See All Timekeeping & Real-Time Clocks (80)

Diagram

Typical Operating Circuit

Application Notes

Application Note 3482: Interfacing a DS1388 Real-Time Clock with an 8051-Type Microcontroller - DS1388
Application Note 3921: Using a DS1307 with a PIC Microcontroller - DS1388

Reliability Reports

Reliability Report: DS1388.pdf

Underwriters Laboratories (UL®) Recognized

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: 1-8 of 8

DS1388 Free
Sample Buy Status Recommended Replacement

Package: TYPE PINS FOOTPRINT

DRAWING CODE/VAR *

Temp RoHS/Lead-Free?
Materials Analysis

DS1388Z-3+T&R

Active
SOIC(N);8 pin;31 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

DS1388Z-3 N/A No Longer Available DS1388Z-3+
SOIC(N);8 pin;31 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

DS1388Z-33 N/A No Longer Available DS1388Z-33+
SOIC(N);8 pin;31 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

DS1388Z-5 N/A No Longer Available DS1388Z-5+
SOIC(N);8 pin;31 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

DS1388Z-3+

Active
SOIC(N);8 pin;31 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

DS1388Z-33+

Active
SOIC(N);8 pin;31 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

DS1388Z-5+

Active
SOIC(N);8 pin;31 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

DS1388Z-33+T&R

Active
SOIC(N);8 pin;31 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

More Information

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Document Ref.: 19-4984; 2009-10-14
This page last modified: 2009-10-14