MAX6909EO33 Maxim Integrated, MAX6909EO33 Datasheet

MAX6909EO33

Manufacturer Part Number

MAX6909EO33

Description

Real Time Clock

Manufacturer

Maxim Integrated

Series

MAX6909, MAX6910r

Datasheet

1.MAX6909EO33T.pdf (33 pages)

Specifications of MAX6909EO33

Function

Clock, Calendar, Watchdog Timekeeper, NV SRAM Control

Rtc Bus Interface

Serial

Time Format

Rtc Memory Size

31 B

Supply Voltage - Max

3.6 V

Supply Voltage - Min

3 V

Maximum Operating Temperature

+ 85 C

Minimum Operating Temperature

- 40 C

Mounting Style

SMD/SMT

Package / Case

QSOP-20

Current page: 1 of 33
Download datasheet (773Kb)

The MAX6909/MAX6910 are I

clocks (RTCs) with a microprocessor supervisor, option-

al trickle charger (MAX6910 only), backup power

source, and NV RAM controller. The MAX6909/

MAX6910 provide alarm outputs to indicate a crystal fail-

ure, a switchover to battery power, and time and date

indication. The NV RAM is 31 bytes of static RAM that

are available for scratchpad storage. The MAX6909/

MAX6910 are controlled through a 2-wire serial bus.

The real-time clock/calendar provides seconds, min-

utes, hours, day, date, month, and year information.

The date is automatically adjusted for months with

fewer than 31 days, including corrections for leap year

up to the year 2100. The clock operates in either the

24-hour or 12-hour format with an AM/PM indicator. A

time/date-programmable ALARM output completes the

features list for the real-time clock section of the

MAX6909/MAX6910. The alarm function can also be

used in a polled mode by periodically reading the

alarm out status bit in the minutes register. A crystal fail

output, CX FAIL, indicates loss of accurate timekeeping

due to crystal problems.

A built-in µP supervisor with an open-drain reset

ensures the µP powers up in a known state. A reset

threshold is available for 3V or 3.3V supplies. The piezo

transducer output, PZT, is register selectable for one of

four frequencies, can be turned on and off through a

output, goes active.

The MAX6909/MAX6910 are available in a 20-pin QSOP

package and operate over the -40°C to +85°C temper-

ature range.

19-3322; Rev 0; 8/04

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at

1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

Point-of-Sale Equipment

Programmable Logic Controller

Handheld Instruments

Medical Instrumentation

________________________________________________________________ Maxim Integrated Products

C-Compatible Real-Time Clocks with µP

General Description

C-compatible real-time

Supervisor and NV RAM Controller

Applications

♦ RTC Counts Seconds, Minutes, Hours, Date of the

♦ 31 Bytes of RAM for Scratchpad Data Storage

♦ Uses Standard 32.768kHz, 6pF Load, Watch

♦ Programmable Time/Date, Open-Drain ALARM

♦ Chip Enable Gating (Control of CE with Reset and

♦ OUT Pin for SRAM Power

♦ µP Reset Output

♦ Watchdog Input

♦ Manual Reset Input with Push-Button Switch

♦ Independent Power-Fail and Reset Comparators

♦ 400kHz 2-Wire Interface

♦ Single-Byte or Multiple-Byte (Burst Mode) Data

♦ Bus Timeout to Prevent Lockup of Malfunctioning

♦ Dual Power-Supply Pins for Primary and Backup

♦ Programmable Trickle Charger (MAX6910)

♦ Uses Less than 1µA Timekeeping Current at 3.0V

♦ Operating Voltages of 3V and 3.3V

Pin Configuration/Selector Guide/Typical Operating Circuit

appear at end of data sheet.

MAX6909EO30

MAX6909EO33

MAX6910EO30

MAX6910EO33

Month, Month, Day of the Week, and Year, with

Leap Year Compensation Valid Up to 2100

Crystal

Output (Status Can also Be Polled)

Power Valid)

Debounce

Transfer for Read or Write of Clock Registers or

RAM

Bus Interface

Power

PART

Ordering Information

-40°C to +85°C

TEMP RANGE

PIN-PACKAGE

20 QSOP

Features

Related parts for MAX6909EO33

MAX6909EO33 Summary of contents

Page 1

... Dual Power-Supply Pins for Primary and Backup Power ♦ Programmable Trickle Charger (MAX6910) ♦ Uses Less than 1µA Timekeeping Current at 3.0V ♦ Operating Voltages of 3V and 3.3V Applications PART MAX6909EO30 MAX6909EO33 MAX6910EO30 MAX6910EO33 Pin Configuration/Selector Guide/Typical Operating Circuit appear at end of data sheet. Features Ordering Information TEMP RANGE PIN-PACKAGE -40° ...

Page 2

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller ABSOLUTE MAXIMUM RATINGS All Voltages (with respect to GND) BATT or V ..........................................................-0.3V to +6.0V CC OUT, ALM, SCL, SDA, CX FAIL, PFO, RESET.......................................................-0.3V to +6.0V All Other ...

Page 3

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller ELECTRICAL CHARACTERISTICS (continued -40°C to +85°C, unless otherwise noted. Typical values are CC(MIN) CC(MAX) A PARAMETER SYMBOL ...

Page 4

Page 5

Page 6

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller AC ELECTRICAL CHARACTERISTICS (V < V < -40°C to +85°C, unless otherwise noted.) (Note 2) CC(MIN) CC CC(MAX) A PARAMETER SYMBOL 2-WIRE BUS TIMING ...

Page 7

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller (V = 3.3V 3V +25°C, unless otherwise noted.) CC BATT OUT VOLTAGE CC vs. TEMPERATURE 100 ...

Page 8

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller (V = 3.3V 3V +25°C, unless otherwise noted.) CC BATT A PFI-TO-PFO DELAY vs. TEMPERATURE 13.0 PFI FALLING AT 10V/ms 12.5 12.0 11.5 11.0 ...

Page 9

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller PIN NAME Backup Battery Input. When V 1 BATT Connect BATT to GND if no backup battery supply is used. Supply Output for CMOS RAM or Other ICs ...

Page 10

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller X1 OSCILLATOR 32.768kHz X2 CRYSTAL- CX_FAIL FAIL DETECT WDI MR PFI CE_IN BATT OUT POWER V CC CONTROL GND BATT_ON SCL INPUT SHIFT REGISTERS SDA ALM Figure 1. ...

Page 11

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller A power-fail comparator is available to monitor other system voltages through PFI and report the status through PFO. If the MAX6909/MAX6910 are in reset, PFO is low; otherwise, ...

Page 12

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Table 1. Crystal Manufacturers and Part Numbers MANUFACTURER AWS2A-32.768KHz, Caliber Electronics AWS2B-32.768KHz ECS INC International ECS-.327-6.0-17 Fox Electronics FSM327 M-tron SX2010/ SX2020 Raltron RSE-32.768-6-C-T Timekeeping accuracy of the ...

Page 13

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Table 2. Acceptable Quartz Crystal Parameters PARAMETER Frequency Equivalent series resistance (ESR) Parallel load capacitance Q factor After 1 month that translates to:   hr min  ...

Page 14

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller REGISTER ADDRESS FUNCTION SEC MIN DATE MONTH ...

Page 15

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller REGISTER ADDRESS FUNCTION STATUS CONFIG ALARM THRESHOLDS: SEC MIN ...

Page 16

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Table 3. Hex Register Address/Description WRITE (HEX) READ (HEX Seconds 82 83 Minutes 84 85 Hours 86 87 Date 88 89 Month 8A 8B Day 8C ...

Page 17

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Table 3. Hex Register Address/Description (continued) WRITE (HEX) READ (HEX RAM RAM RAM RAM ...

Page 18

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Table 4. Trickle-Charger Register Control TCS TCS TCS TCS ...

Page 19

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Table 5. MAX6910 I/O and IC Sections Powered from V DESCRIPTION Crystal Oscillator I/O Crystal Oscillator I/O Backup Power-Supply Input OUT (> BATT if V ...

Page 20

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Alarm Generation Registers The alarm function generates an ALARM when the con- tents of the SEC, MIN, HR, DATE, MONTH, DAY, or YEAR registers match the respective alarm ...

Page 21

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Negative-Going V The MAX6909/MAX6910 are relatively immune to short- duration negative transients (glitches) while issuing resets to the µP during power-up, power-down, and brownout conditions. Therefore, resetting the ...

Page 22

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller START SET WDI HIGH PROGRAM CODE SUBROUTINE OR PROGRAM LOOP SET WDI LOW RETURN Figure 10. Watchdog Flow Diagram Watchdog Software Considerations There is a way to help ...

Page 23

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller V RST OUT V t BATT RP RESET Figure 12. Chip-Enable Timing MR CE OUT t RCE RESET CE IN Figure ...

Page 24

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller Piezo Transducer Output Drive The push-pull, piezo transducer drive output, PZT, is selectable through the configuration register for fre- quencies of 1.024kHz, 2.048kHz, 4.096kHz, or 8.192kHz (Table 6). ...

Page 25

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller START BIT 7 CONDITION MSB (S) (A7) t LOW t SU:STA BUF t HD:STA Figure 17. 2-Wire Bus Timing Diagram TIME_OUT_CLR CLR 1Hz_CLK Q1 CNT_UP ...

Page 26

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller 1Hz_CLK TIME_OUT_CLR VALID START CONDITION SDA SCL TIME_OUT Figure 19. Normal 2-Wire Bus Operation 1Hz_CLK TIME_OUT_CLR VALID START CONDITION SDA SCL TIME_OUT t1 Figure 20. Timeout 2-Wire Bus ...

Page 27

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller START and STOP Conditions Both SDA and SCL remain high when the bus is not busy. A high-to-low transition of SDA, while SCL is high, is defined as ...

Page 28

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller The most accurate way to read the timekeeping regis- ters burst read. In the burst read, the main timekeeping registers (seconds, minutes, hours, date, ...

Page 29

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller R1 PFI PFO PFO IS ACTIVE HIGH WHEN MONITORING A NEGATIVE SUPPLY ( TRIP PFT ...

Page 30

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller PFI MAX6909/ PFO TO µ TRIP PFT ...

Page 31

... C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller UNREGULATED SUPPLY REGULATOR µP Figure 28. Using the Power-Fail Comparator to Generate a Power-Fail Warning Selector Guide RESET THRESHOLD PART (TYP) MAX6909EO30 2.63 MAX6909EO33 2.93 MAX6910EO30 2.63 MAX6910EO33 2.93 ______________________________________________________________________________________ V CC PFI MAX6909/ MAX6910 PFO GND TRICKLE CHARGER ...

Page 32

I C-Compatible Real-Time Clocks with µP Supervisor and NV RAM Controller 1kΩ USER RESET 3.3V RPU RPU = BUS µCONTROLLER CE INTO RESET NMI 3.3V 3.3V MULTIFUNCTION ASIC PFO CX FAIL RST 32 ______________________________________________________________________________________ 12V 6.98kΩ ...

Page 33

... Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 33 © 2004 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products ...

Related keywords

MAX6909EO33 datasheet
MAX6909EO33 data sheet
MAX6909EO33 pdf datasheet
MAX6909EO33 component
MAX6909EO33 part
MAX6909EO33 distributor
MAX6909EO33 RoHS
MAX6909EO33 datasheet download