Overview: YB1921
3-Pin Microprocessor Reset Monitor
Introduction
The YB1921 is a cost-effective system supervisor Integrated Circuit (IC) designed to monitor VCC in digital and mixed signal systems and provide a warning signal when the system power supply is out of working range, and a reset signal to the host processor when necessary. No external ponents are required. The reset output is driven active within 20μsec of VCC falling through the reset voltage threshold. Reset is maintained active for a minimum of 140msec after VCC rises above the reset threshold. The YB1921 has an active-low RESET output. The output of the YB1921 is guaranteed valid down to VCC=1V. The YB1921 is optimized to reject fast transient glitches on the VCC line. Low supply current of 18μA (VCC=3.3V) makes these devices suitable for battery powered applications.
