The MXD1810–MXD1813/MXD1815–MXD1818 family of microprocessor (µP) reset circuits monitor power supplies in µP and digital systems. These devices provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with +2.5V/+3.0V/+3.3V (MXD1815–MXD1818), and +5V (MXD1810–MXD1813) systems. These circuits assert a reset signal whenever the VCC supply voltage declines below a preset threshold, keeping reset asserted for at least 100ms after VCC rises above the reset threshold. The MXD1813/MXD1818 also keep reset asserted for at least 100ms after the output is momentarily pulled to GND by an external push-button switch. The MXD1812/MXD1817 have an active-high push-pull RESET output. The MXD1810/MXD1815 (push-pull) and MXD1811/MXD1813/MXD1816/MD1818 (open-drain) have an active-low RESET output. The open-drain devices (MXD1811/MXD1813/MXD1816/MXD1818) have an internal pullup resistor to VCC. The MXD1813/MXD1818 feature a debounced manual reset feature that asserts a reset if the active-low RESET pin is pulled low for more than 1.5µs. When used to initiate manual reset, active-low RESET debounces signals from devices such as mechanical switches. For devices with this feature, the release of the external switch triggers the reset period. The MXD1810–MXD1813/MXD1815–MXD1818 are guaranteed to output the correct logic state for VCC down to +1V. These ICs provide a reset comparator designed to ignore fast transients on VCC. Reset thresholds are available between +2.18V and +4.62V. These small, low-power (4µA) devices are ideal for use in portable equipment. All are available in space-saving 3-pin SC70 and SOT23 packages, and are specified from -40°C to +105°C.
Precision Monitoring of +2.5V, +3V, +3.3V, and +5V Power-Supply Voltages