X25043 Datasheet, PDF (1/15 Pages) Xicor Inc. – Programmable Watchdog Supervisory E2PROM

APPLICATION NOTES
AVA I L A B L E
X25043/45^{AN11 • AN21}
4K
X25043/45
512 x 8 Bit
Programmable Watchdog Supervisory E²PROM
FEATURES
• Programmable Watchdog Timer
• Low VCC Detection
• Reset Signal Valid to VCC = 1V
• 1MHz Clock Rate
• 512 X 8 Bits Serial E²PROM
—4 Byte Page Mode
• Low Power CMOS
—50µA Standby Current
—3mA Active Current
• 2.7V To 5.5V Power Supply
• Block Lock^TM
—Protect 1/4, 1/2 or all of E²PROM Array
• Built-in Inadvertent Write Protection
—Power-Up/Power-Down protection circuitry
—Write Latch
—Write Protect Pin
• High Reliability
—Endurance: 100,000 cycles per byte
—Data Retention: 100 Years
—ESD protection: 2000V on all pins
• Available Packages
—8-Lead PDlP
—8-Lead SOIC
—14-Lead TSSOP
• X25043 = Active LOW RESET
• X25045 = Active HIGH RESET
DESCRIPTION
The X25043/45 combines three popular functions,
Watchdog Timer, Voltage Supervision, and E²PROM in
a single package. This combination lowers the system
cost and reduces the board space requirements.
The Watchdog Timer provides an independent protec-
tion system for microcontrollers. During a system failure,
the X25043/45 watchdog will respond with a RESET/
RESET signal after a selectable time-out interval. The
user selects the interval from three preset values. Once
selected, the interval does not change, even after cy-
cling the power.
The system is protected from low voltage conditions by
the X25043/45 low V_CC detection circuits. When V_CC
drops below the minimum V_CC trip point, the system is
reset. Reset is asserted until V_CC returns and stabilizes.
The memory portion of the X25043/45 is a CMOS 4096-
bit serial E²PROM, internally organized as 512 X 8. The
X25043/45 features a Serial Peripheral Interface (SPI)
and software protocol allowing operation on a simple
three-wire bus.
The X25043/45 utilizes Xicor’s proprietary Direct Write™
cell, providing a minimum endurance of 100,000 cycles
per byte and a minimum data retention of 100 years.
DIE PHOTOGRAPH
RESET
CONTROL
LOGIC
PROGRAMMABLE
VOLTAGE
SENSOR
SERIAL
INTERFACE
LOGIC
Direct Write™ is a trademark of Xicor, Inc.
©Xicor, Inc. 1994, 1995, 1996 Patents Pending
3844-6.5 5/9/96 T4/C2/D2 NS
4K BITS E²²PROM
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AANNDD
CCOONNTTRROOLL
1
W
A
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C
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D
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3844 ILL F01
Characteristics subject to change without notice