GENERAL DESCRIPTION
The HWD803/HWD809/HWD810 are microprocessor (µP) supervisory circuits used to monitor the power supplies in µP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +5V, +3.3V, +3.0V, or +2.5V powered circuits. These circuits perform a single function: they assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds suitable for operation with a variety of supply voltages are available. The HWD803 has an open-drain output stage, while the HWD809/HWD810 have push-pull outputs. The HWD803’s open-drain RESET output requires a pull-up resistor that can be connected to a voltage higher than VCC. The HWD803/HWD809 have an active-low RESET output, while the HWD810 has an active-high RESET output. Low supply current makes the HWD803/HWD809/ HWD810 ideal for use in portable equipment.
Chengdu Sino Microelectronics System
