Rainbow Electronics MAX6902 - Manual

General Description
The MAX6902 SPI™-compatible real-time clock con-
tains a real-time clock/calendar and 31 x 8 bits of static
random-access memory (SRAM). The real-time
clock/calendar provides seconds, minutes, hours, day,
date, month, year, and century information. A time/date
programmable polled ALARM is included in the
MAX6902. The end-of-the-month 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 24hr or 12hr format with an
AM/PM indicator. The MAX6902 operates with a supply
voltage of +2V to +5.5V, is available in the ultra-small
8-pin TDFN package, and works over the -40°C to
+85°C industrial temperature range.
Applications
Point-of-Sale Equipment
Intelligent Instruments
Fax Machines
Battery-Powered Products
Portable Instruments
Features
♦ Real-Time Clock Counts Seconds, Minutes, Hours,
Day of Week, Date of Month, Month, Year, and Century
♦ Leap-Year Compensation Valid up to Year 2100
♦ +2V to +5.5V Wide Operating Voltage Range
♦ SPI Interface: 4MHz at 5V; 1MHz at 2V
♦ 31 x 8-Bit SRAM for Scratchpad Data Storage
♦ Uses Standard 32.768kHz, 12.5pF Watch Crystal
♦ Low Timekeeping Current (400nA at 2V)
♦ Single-Byte or Multiple-Byte (Burst Mode) Data
Transfer for Read or Write of Clock Registers or
SRAM
♦ Ultra-Small 8-Pin 3mm x 3mm x 0.8mm TDFN
Package
♦ Programmable Time/Date Polled ALARM Function
♦ No External Crystal Bias Resistors or Capacitors
Required
MAX6902
SPI-Compatible RTC in a TDFN
________________________________________________________________ Maxim Integrated Products 1
Pin Configuration
Ordering Information
Typical Operating Circuit
19-2134; Rev 1; 7/03
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.
PART
TEMP
RANGE
PIN-
PACKAGE TOP
MARK
MAX6902ETA-T -40 °C to +85°C 8 TDFN AGT
V
CC
CS GND
1
2
8
7
X1
X2 DOUT
DIN
SCLK
TDFN
TOP VIEW
3
4
6
5
MAX6902
MAX6902
+3.3V
+3.3V
GND
V CC
0.1 µF
µc
1
X1
X2
5
2
3
SCLK
32.768kHz
CRYSTAL
CS
DOUT
DIN
4
8
7
6
I 2 C is a trademark of Philips Corp. Purchase of I 2 C components of Maxim Integrated Products, Inc., or one of its sublicensed
Associated Companies, conveys a license under the Philips I 2 C Patent rights to use these components in an I 2 C system provided that
the system conforms to the I 2 C Standard Specification as defined by Philips.
SPI is a trademark of Motorola, Inc.
PART
SERIAL
INTERFACE
SRAM
ALARM
FUNCTION
OUTPUT
FREQUENCY
PIN-
PACKAGE
MAX6900 I 2 C™ compatible 31 ✕ 8 — — 6 TDFN
MAX6901 3 Wire 31 ✕ 8 Polled 32kHz 8 TDFN
MAX6902 SPI compatible 31 ✕ 8 Polled — 8 TDFN
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