These devices combine four popular functions, Power-on

Reset Control, Watchdog Timer, Supply Voltage Supervision,

and Block Lock Protect 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 minimum VCC trip point. RESET/RESET is

asserted until VCC returns to proper operating level and

stabilizes. Five 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.