MAX6902 Datasheet, PDF (1/18 Pages) Maxim Integrated Products – SPI-Compatible RTC in a TDFN

19-2134; Rev 1; 7/03
SPI-Compatible RTC in a TDFN
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.
Point-of-Sale Equipment
Intelligent Instruments
Fax Machines
Battery-Powered Products
Portable Instruments
Applications
PART
MAX6900
MAX6901
MAX6902
SERIAL
INTERFACE
I²C™ compatible
3 Wire
SPI compatible
SRAM
31 ✕ 8
31 ✕ 8
31 ✕ 8
Typical Operating Circuit
+3.3V _0.1µF
+3.3V
µc
6
V_CC
MAX6902
1 _SCLK
5 _CS
2 _DOUT
3 _DIN
GND
4
X1 ⁸
X2 ⁷
32.768kHz
CRYSTAL
Features
o Real-Time Clock Counts Seconds, Minutes, Hours,
Day of Week, Date of Month, Month, Year, and Century
o Leap-Year Compensation Valid up to Year 2100
o +2V to +5.5V Wide Operating Voltage Range
o SPI Interface: 4MHz at 5V; 1MHz at 2V
o 31 x 8-Bit SRAM for Scratchpad Data Storage
o Uses Standard 32.768kHz, 12.5pF Watch Crystal
o Low Timekeeping Current (400nA at 2V)
o Single-Byte or Multiple-Byte (Burst Mode) Data
Transfer for Read or Write of Clock Registers or
SRAM
o Ultra-Small 8-Pin 3mm x 3mm x 0.8mm TDFN
Package
o Programmable Time/Date Polled ALARM Function
o No External Crystal Bias Resistors or Capacitors
Required
Ordering Information
PART
MAX6902ETA-T
TEMP
RANGE
-40°C to +85°C
PIN-
PACKAGE
8 TDFN
TOP
MARK
AGT
Related Real-Time Clock Products
ALARM
FUNCTION
—
Polled
Polled
OUTPUT
FREQUENCY
—
32kHz
—
PIN-
PACKAGE
6 TDFN
8 TDFN
8 TDFN
Pin Configuration
TOP VIEW
SCLK 1
DOUT 2
DIN 3
GND 4
MAX6902
8 X1
7 X2
6 V_CC
5 CS
TDFN
I²C is a trademark of Philips Corp. Purchase of I²C components of Maxim Integrated Products, Inc., or one of its sublicensed
Associated Companies, conveys a license under the Philips I²C Patent rights to use these components in an I²C system provided that
the system conforms to the I²C Standard Specification as defined by Philips.
SPI is a trademark of Motorola, Inc.
________________________________________________________________ Maxim Integrated Products 1
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.