YB1921
3-Pin Microprocessor Reset Monitor
Introduction
The YB1921 is a cost-effective system
supervisor Integrated Circuit (IC) designed to monitor
V
CC
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 components
are required.
The reset output is driven active within 20μsec
of V
CC
falling through the reset voltage threshold.
Reset is maintained active for a minimum of 140msec
after V
CC
rises above the reset threshold. The YB1921
has an active-low RESET output. The output of the
YB1921 is guaranteed valid down to V
CC
=1V.
The YB1921 is optimized to reject fast transient
glitches on the V
CC
line. Low supply current of 18μA
(V
CC
=3.3V) makes these devices suitable for battery
powered applications.
Features
Precision V
CC
Monitor for 2.8V, 3.0V, 3.3V,
and 5.0V Supplies
140msec Guaranteed Minimum RESET
Output Duration
RESET Output Guaranteed to V
CC
=1.0V
Low 18μA Supply Current
V
CC
Transient Immunity
Small SOT-23 Package
No External Components
Wide Operating Temperature: 0°C to 85°C
Applications
Computers
Embedded systems
Battery powered equipment
Critical µP power supply monitoring
Application Diagram
YB1921
www.yobon.com.tw
1
YOBON [ YOBON TECHNOLOGIES,INC. ]
