Rainbow Electronics DS28DG02 - Manual

1 of 33 REV: 061907
Note: Some revisions of this device may incorporate deviations from published specifications known as errata. Multiple revisions of any device
may be simultaneously available through various sales channels. For information about device errata, click here:
www.maxim-ic.com/errata .
DS28DG02
2kb SPI EEPROM with PIO, RTC,
Reset, Battery Monitor, and Watchdog
GENERAL DESCRIPTION
The DS28DG02 combines 2kb (256 x 8) EEPROM
with 12 PIO lines, a real-time clock (RTC) and
calendar with alarm function, a CPU reset monitor, a
battery monitor, and a watchdog. Communication
with the device is accomplished with an industry-
standard SPI™ interface. The user EEPROM is
organized as four blocks of 64 bytes each with
single-byte and up to 16-byte page write capability.
Additional registers provide access to PIOs and to
setup functions. Individual PIO lines can be
configured as inputs or outputs. The power-on state
of PIOs programmed as outputs is stored in
nonvolatile (NV) memory. All PIOs may be
reconfigured by the user through the serial interface.
The RTC/calendar operates in the 12/24-hour format
and automatically corrects for leap years. Battery
monitor threshold and watchdog timeout are user-
programmable through NV registers. The reset
monitor generates a reset to the CPU if the voltage at
the V
CC
pin falls below the factory-set limit. The reset
output includes a debounce circuit for manual
pushbutton reset.
APPLICATIONS
Asset-Tracking Systems
Broadband Access Network Equipment
Patient-Monitoring Systems
Home Lighting Control Systems
Holter Heart Monitors
Typical Operating Circuit appears on page 32.
Pin Configuration appears on page 33.
FEATURES
ƒ 2kb (256 x 8) EEPROM Organized in Four
64-Byte Blocks
ƒ Single Byte and Up to 16-Byte EEPROM Write
Sequences
ƒ EEPROM Write-Protect Control Pin Protects
1, 2, or All 4 Blocks
ƒ Endurance 200k Cycles per Page at +25°C;
10ms (max) EEPROM Write Cycle
ƒ SPI Serial Interface Supporting Modes (0,0)
and (1,1) at Up to 2MHz Clock Frequency
ƒ 12 PIO Lines with LED Drive Capability
ƒ Each PIO is Configured to Input or Output,
Open-Drain/Push-Pull on Startup by Stored
Value
ƒ All PIOs are Reconfigurable After Startup
ƒ RTC/Calendar/Alarm with BCD Format and
Leap-Year Compensation
ƒ RTC Controlled Through 32.768kHz, 12.5pF
Crystal or External TCXO
ƒ CPU Reset Through Fast-Response Precision
V
CC
Monitor with Hysteresis or Pushbutton
ƒ Battery Monitor 2.5V, 2.25V, 2.0V, 1.75V, -5%
ƒ Watchdog Timer 1.6s, 0.8s, 0.4s, 0.2s (typ)
ƒ Unique Factory-Programmed 64-Bit Device
Registration Number
ƒ Operating Range: 2.2V to 5.25V,
-40°C to +85°C
ƒ ±4kV IEC 1000-4-2 ESD Protection Level
(Except Crystal Pins)
ƒ Available in 28-Lead, 4.4mm TSSOP or
36-Lead 6mm × 6mm QFN Package
ORDERING INFORMATION
PART TEMP RANGE V
CC
TRIP PIN-PACKAGE PKG CODE
DS28DG02E-3C+ -40°C to +85°C 3.3V -5% 28 TSSOP-EP * (4.4mm) U28E+5
DS28DG02E-3C+T -40°C to +85°C 3.3V -5% 28 TSSOP-EP * T&R U28E+5
DS28DG02G-3C+ -40°C to +85°C 3.3V -5% 36 TQFN-EP * (6mm × 6mm) T3666+3
DS28DG02G-3C+T -40°C to +85°C 3.3V -5% 36 TQFN-EP * T&R T3666+3
*EP = Exposed Paddle.
+ Denotes lead-free/RoHS compliant device.
For additional V
CC
monitor trip points or other device options, contact the factory.
Note: Registers are capitalized for clarity.
SPI is a trademark of Motorola, Inc.
www.maxim-ic.com