DESCRIPTION
The X4163, X4165 combines four popular functions,
Power-on Reset Control, Watchdog Timer, Supply Voltage Supervision, and Serial EEPROM Memory in one
package. This combination lowers system cost,
reduces board space requirements, and increases reliability.
Applying power to the device activates the power on
reset circuit which holds RESET/RESET active for a
period of time. This allows the power supply and oscillator to stabilize before the processor can execute code.
The Watchdog Timer provides an independent protection mechanism for microcontrollers. When the microcontroller fails to restart a timer within a selectable
time out interval, the device activates the
RESET/RESET signal. The user selects the interval
from three preset values. Once selected, the interval
does not change, even after cycling the power.
The device’s low VCC detection circuitry protects the
user’s system from low voltage conditions, resetting the
system when VCC falls below the set minimum VCC trip
point. RESET/RESET is asserted until VCC returns to
proper operating level and stabilizes. Four industry
standard VTRIP thresholds are available, however, Intersil’s unique circuits allow the threshold to be reprogrammed to meet custom requirements or to fine-tune
the threshold for applications requiring higher precision.

FEATURES
• Selectable watchdog timer
• Low VCC detection and reset assertion
—Four standard reset threshold voltages
—Adjust low VCC reset threshold voltage using
special programming sequence
—Reset signal valid to VCC = 1V
• Low power CMOS
—<20µA max standby current, watchdog on
—<1µA standby current, watchdog OFF
—3mA active current
• 16Kbits of EEPROM
—64-byte page write mode
—Self-timed write cycle
—5ms write cycle time (typical)
• Built-in inadvertent write protection
—Power-up/power-down protection circuitry
—Block Lock (1, 2, 4, 8 pages, all, none)
• 400kHz 2-wire interface
• 2.7V to 5.5V power supply operation
• Available Packages
—8 Ld SOIC
—8 Ld TSSOP
• Pb-free plus anneal available (RoHS compliant)